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Demaret T, Bédard K, Soucy JF, Watkins D, Allard P, Levtova A, O'Brien A, Brunel-Guitton C, Rosenblatt DS, Mitchell GA. The MMACHC variant c.158T>C: Mild clinical and biochemical phenotypes and marked hydroxocobalamin response in cblC patients. Mol Genet Metab 2024; 142:108345. [PMID: 38387306 DOI: 10.1016/j.ymgme.2024.108345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/08/2024] [Accepted: 02/09/2024] [Indexed: 02/24/2024]
Abstract
Mutations in MMACHC cause cobalamin C disease (cblC, OMIM 277400), the commonest inborn error of vitamin B12 metabolism. In cblC, deficient activation of cobalamin results in methylcobalamin and adenosylcobalamin deficiency, elevating methylmalonic acid (MMA) and total plasma homocysteine (tHcy). We retrospectively reviewed the medical files of seven cblC patients: three compound heterozygotes for the MMACHC (NM_015506.3) missense variant c.158T>C p.(Leu53Pro) in trans with the common pathogenic mutation c.271dupA (p.(Arg91Lysfs*14), "compounds"), and four c.271dupA homozygotes ("homozygotes"). Compounds receiving hydroxocobalamin intramuscular injection monotherapy had age-appropriate psychomotor performance and normal ophthalmological examinations. In contrast, c.271dupA homozygotes showed marked psychomotor retardation, retinopathy and feeding problems despite penta-therapy (hydroxocobalamin, betaine, folinic acid, l-carnitine and acetylsalicylic acid). Pretreatment levels of plasma and urine MMA and tHcy were higher in c.271dupA homozygotes than in compounds. Under treatment, levels of the compounds approached or entered the reference range but not those of c.271dupA homozygotes (tHcy: compounds 9.8-32.9 μM, homozygotes 41.6-106.8 (normal (N) < 14); plasma MMA: compounds 0.14-0.81 μM, homozygotes, 10.4-61 (N < 0.4); urine MMA: compounds 1.75-48 mmol/mol creatinine, homozygotes 143-493 (N < 10)). Patient skin fibroblasts all had low cobalamin uptake, but this was milder in compound cells. Also, the distribution pattern of cobalamin species was qualitatively different between cells from compounds and from homozygotes. Compared to the classic cblC phenotype presented by c.271dupA homozygous patients, c.[158T>C];[271dupA] compounds had mild clinical and biochemical phenotypes and responded strikingly to hydroxocobalamin monotherapy.
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Affiliation(s)
- Tanguy Demaret
- Medical Genetics Division, Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, Québec, Canada; Centre de Génétique Humaine, Institut de Pathologie et Génétique, Gosselies, Belgium
| | - Karine Bédard
- Medical Genetics Division, Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, Québec, Canada; Laboratoire de Diagnostic Moléculaire, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada; Département de Pathologie et Biologie Cellulaire, Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada
| | - Jean-François Soucy
- Medical Genetics Division, Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, Québec, Canada
| | - David Watkins
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada; Department of Medical Genetics, McGill University Health Centre, Montreal, Quebec, Canada
| | - Pierre Allard
- Medical Genetics Division, Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, Québec, Canada; Department of Biochemistry, CHU Sainte-Justine, Montréal, Québec, Canada
| | - Alina Levtova
- Service de Médecine Génique, Département de Médecine, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Alan O'Brien
- Service de Médecine Génique, Département de Médecine, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Catherine Brunel-Guitton
- Medical Genetics Division, Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, Québec, Canada; Division of Biochemical Genetics, Department of Pediatrics, University of British Columbia, BC Children's Hospital, Vancouver, British Columbia, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada; Department of Medical Genetics, McGill University Health Centre, Montreal, Quebec, Canada
| | - Grant A Mitchell
- Medical Genetics Division, Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, Québec, Canada.
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Bauer WG, Watkins D, Zacharias C, Gilfix BM, Rosenblatt DS. Growth requirement for methionine in human melanoma-derived cell lines with different levels of MMACHC expression and methylation. Mol Genet Metab 2024; 141:108111. [PMID: 38103461 DOI: 10.1016/j.ymgme.2023.108111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/05/2023] [Accepted: 12/06/2023] [Indexed: 12/19/2023]
Abstract
Methionine dependence, the inability to grow in culture when methionine in the medium is replaced by its metabolic precursor homocysteine, occurs in many tumor cell lines. In most affected lines, the cause of methionine dependence is not known. An exception is the melanoma-derived cell line MeWo-LC1, in which hypermethylation of the MMACHC gene is associated with decreased MMACHC expression. Decreased expression results in decreased provision of the methylcobalamin cofactor required for activity of methionine synthase and thus decreased conversion of homocysteine to methionine. Analysis of data in the Cancer Cell Line Encyclopedia Archive demonstrated that MMACHC hypermethylation and decreased MMACHC expression occurred more frequently in melanoma cell lines when compared to other tumor cell lines. We further investigated methionine dependence and aspects of MMACHC function in a panel of six melanoma lines, including both melanoma lines with known methionine dependence status (MeWo, which is methionine independent, and A375, which is methionine dependent). We found that the previously unclassified melanoma lines HMCB, Colo829 and SH-4 were methionine dependent, while SK-Mel-28 was methionine independent. However, despite varying levels of MMACHC methylation and expression, none of the tested lines had decreased methylcobalamin and adenosylcobalamin synthesis as seen in MeWo-LC1, and the functions of both cobalamin-dependent enzymes methionine synthase and methylmalonyl-CoA mutase were intact. Thus, while melanoma lines were characterized by relatively high levels of MMACHC methylation and low expression, the defect in metabolism observed in MeWo-LC1 was unique, and decreased MMACHC expression was not a cause of methionine dependence in the other melanoma lines.
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Affiliation(s)
- William G Bauer
- Department of Human Genetics, McGill University, Montreal, Canada; Child Health and Human Development, Research Institute, McGill University Health Centre, Montreal, Quebec, Canada
| | - David Watkins
- Department of Human Genetics, McGill University, Montreal, Canada; Child Health and Human Development, Research Institute, McGill University Health Centre, Montreal, Quebec, Canada.
| | - Caitlin Zacharias
- Child Health and Human Development, Research Institute, McGill University Health Centre, Montreal, Quebec, Canada
| | - Brian M Gilfix
- Child Health and Human Development, Research Institute, McGill University Health Centre, Montreal, Quebec, Canada; Division of Medical Biochemistry, Department of Specialized Medicine, McGill University Health Centre, Montreal, Quebec, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Canada; Child Health and Human Development, Research Institute, McGill University Health Centre, Montreal, Quebec, Canada; Division of Medical Biochemistry, Department of Specialized Medicine, McGill University Health Centre, Montreal, Quebec, Canada; Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, Montreal, Quebec, Canada
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Melvill K, Fitzpatrick J, Rosenblatt DS. Perspective on the future of genetic counseling assistants - Should it be a steppingstone or a stand-alone career? Mol Genet Metab 2023; 138:107370. [PMID: 36603531 DOI: 10.1016/j.ymgme.2022.107370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 12/23/2022] [Accepted: 12/24/2022] [Indexed: 12/29/2022]
Affiliation(s)
- Kenzie Melvill
- Department of Human Genetics, McGill University, Montreal, QC, Canada; Division of Medical Genetics, Department of Specialized Medicine, Jewish General Hospital, Montreal, QC, Canada
| | | | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, QC, Canada; Division of Medical Genetics, Department of Specialized Medicine, Jewish General Hospital, Montreal, QC, Canada.
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Nunes GDC, Grenier K, Kron CM, Kitzler T, Helou JE, Rosenblatt DS, Olivier F. Pulmonary lymphangiectasia in myotubular myopathy: a novel unrecognized association? Neuromuscul Disord 2022; 32:512-515. [DOI: 10.1016/j.nmd.2022.04.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 04/27/2022] [Accepted: 04/29/2022] [Indexed: 01/21/2023]
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Abstract
Cobalamin (vitamin B12) is required for activity of the enzymes methylmalonyl-CoA mutase and methionine synthase in human cells. Inborn errors affecting cobalamin uptake or metabolism are characterized by accumulation of the substrates for these enzymes, methylmalonic acid and homocysteine, in blood and urine. Inborn errors affecting synthesis of the adenosylcobalamin coenzyme required by methylmalonyl-CoA mutase (cblA and cblB) result in isolated methylmalonic aciduria; inborn errors affecting synthesis of the methylcobalamin coenzyme required by methionine synthase (cblE and cblG) result in isolated homocystinuria. Combined methylmalonic aciduria and homocystinuria is seen in patients with impaired intestinal cobalamin absorption (intrinsic factor deficiency, Imerslund-Gräsbeck syndrome) and with defects affecting synthesis of both cobalamin coenzymes (cblC, cblD, cblF and cblJ). A series of disorders caused by pathogenic variant mutations affecting gene regulators (transcription factors) of the MMACHC gene have recently been described (HCFC1 [cblX disorder] and deficiencies of THAP11, and ZNF143 [the cblK disorder]).
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Affiliation(s)
- David Watkins
- Department of Human Genetics, McGill University, The Research Institute of the McGill University Health Centre, Montreal, QC, Canada.
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, The Research Institute of the McGill University Health Centre, Montreal, QC, Canada
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Oussalah A, Siblini Y, Hergalant S, Chéry C, Rouyer P, Cavicchi C, Guerrini R, Morange PE, Trégouët D, Pupavac M, Watkins D, Pastinen T, Chung WK, Ficicioglu C, Feillet F, Froese DS, Baumgartner MR, Benoist JF, Majewski J, Morrone A, Rosenblatt DS, Guéant JL. Epimutations in both the TESK2 and MMACHC promoters in the Epi-cblC inherited disorder of intracellular metabolism of vitamin B 12. Clin Epigenetics 2022; 14:52. [PMID: 35440018 PMCID: PMC9020039 DOI: 10.1186/s13148-022-01271-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 04/05/2022] [Indexed: 03/14/2023] Open
Abstract
Background epi-cblC is a recently discovered inherited disorder of intracellular vitamin B12 metabolism associating hematological, neurological, and cardiometabolic outcomes. It is produced by an epimutation at the promoter common to CCDC163P and MMACHC, which results from an aberrant antisense transcription due to splicing mutations in the antisense PRDX1 gene neighboring MMACHC. We studied whether the aberrant transcription produced a second epimutation by encompassing the CpG island of the TESK2 gene neighboring CCDC163P.
Methods We unraveled the methylome architecture of the CCDC163P–MMACHC CpG island (CpG:33) and the TESK2 CpG island (CpG:51) of 17 epi-cblC cases. We performed an integrative analysis of the DNA methylome profiling, transcriptome reconstruction of RNA-sequencing (RNA-seq), chromatin immunoprecipitation sequencing (ChIP-Seq) of histone H3, and transcription expression of MMACHC and TESK2.
Results The PRDX1 splice mutations and activation of numerous cryptic splice sites produced antisense readthrough transcripts encompassing the bidirectional MMACHC/CCDC163P promoter and the TESK2 promoter, resulting in the silencing of both the MMACHC and TESK2 genes through the deposition of SETD2-dependent H3K36me3 marks and the generation of epimutations in the CpG islands of the two promoters. Conclusions The antisense readthrough transcription of the mutated PRDX1 produces an epigenetic silencing of MMACHC and TESK2. We propose using the term 'epi-digenism' to define this epigenetic disorder that affects two genes. Epi-cblC is an entity that differs from cblC. Indeed, the PRDX1 and TESK2 altered expressions are observed in epi-cblC but not in cblC, suggesting further evaluating the potential consequences on cancer risk and spermatogenesis. Supplementary Information The online version contains supplementary material available at 10.1186/s13148-022-01271-1.
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Affiliation(s)
- Abderrahim Oussalah
- INSERM UMR_S 1256, Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, 9 Avenue de la Forêt de Haye, 54000, Nancy, France.,Reference Center for Inborn Errors of Metabolism (ORPHA67872), University Hospital of Nancy, 54000, Nancy, France.,Department of Molecular Medicine, Division of Biochemistry, Molecular Biology and Nutrition, University Hospital of Nancy, 54000, Nancy, France
| | - Youssef Siblini
- INSERM UMR_S 1256, Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, 9 Avenue de la Forêt de Haye, 54000, Nancy, France
| | - Sébastien Hergalant
- INSERM UMR_S 1256, Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, 9 Avenue de la Forêt de Haye, 54000, Nancy, France
| | - Céline Chéry
- INSERM UMR_S 1256, Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, 9 Avenue de la Forêt de Haye, 54000, Nancy, France.,Reference Center for Inborn Errors of Metabolism (ORPHA67872), University Hospital of Nancy, 54000, Nancy, France.,Department of Molecular Medicine, Division of Biochemistry, Molecular Biology and Nutrition, University Hospital of Nancy, 54000, Nancy, France
| | - Pierre Rouyer
- INSERM UMR_S 1256, Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, 9 Avenue de la Forêt de Haye, 54000, Nancy, France
| | - Catia Cavicchi
- Molecular and Cell Biology Laboratory of Neurometabolic Diseases, Paediatric Neurology Unit and Laboratories, Meyer Children's Hospital, Viale Pieraccini 24, 50139, Florence, Italy
| | - Renzo Guerrini
- Molecular and Cell Biology Laboratory of Neurometabolic Diseases, Paediatric Neurology Unit and Laboratories, Meyer Children's Hospital, Viale Pieraccini 24, 50139, Florence, Italy.,Department of NEUROFARBA, University of Florence, Florence, Italy
| | - Pierre-Emmanuel Morange
- INSERM UMR_S 1263, Center for CardioVascular and Nutrition Research (C2VN), Aix-Marseille University, 13385, Marseille, France
| | - David Trégouët
- INSERM, BPH, U1219, Université Bordeaux, 33000, Bordeaux, France
| | - Mihaela Pupavac
- Department of Human Genetics, McGill University and Research Institute, McGill University Health Centre, Montreal, QC, H4A 3J1, Canada
| | - David Watkins
- Department of Human Genetics, McGill University and Research Institute, McGill University Health Centre, Montreal, QC, H4A 3J1, Canada
| | - Tomi Pastinen
- Department of Human Genetics, McGill University and Research Institute, McGill University Health Centre, Montreal, QC, H4A 3J1, Canada
| | - Wendy K Chung
- Departments of Pediatrics and Medicine, Columbia University, New York, USA
| | - Can Ficicioglu
- Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - François Feillet
- INSERM UMR_S 1256, Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, 9 Avenue de la Forêt de Haye, 54000, Nancy, France.,Reference Center for Inborn Errors of Metabolism (ORPHA67872), University Hospital of Nancy, 54000, Nancy, France
| | - D Sean Froese
- Division of Metabolism, University Children's Hospital, University of Zürich, Zürich, Switzerland
| | - Matthias R Baumgartner
- Division of Metabolism, University Children's Hospital, University of Zürich, Zürich, Switzerland
| | - Jean-François Benoist
- Biochemistry Hormonology Laboratory, Robert-Debré University Hospital, APHP, 48 bd Serurier, 75019, Paris, France
| | - Jacek Majewski
- Department of Human Genetics, McGill University and Research Institute, McGill University Health Centre, Montreal, QC, H4A 3J1, Canada
| | - Amelia Morrone
- Molecular and Cell Biology Laboratory of Neurometabolic Diseases, Paediatric Neurology Unit and Laboratories, Meyer Children's Hospital, Viale Pieraccini 24, 50139, Florence, Italy.,Department of NEUROFARBA, University of Florence, Florence, Italy
| | - David S Rosenblatt
- Department of Human Genetics, McGill University and Research Institute, McGill University Health Centre, Montreal, QC, H4A 3J1, Canada
| | - Jean-Louis Guéant
- INSERM UMR_S 1256, Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, 9 Avenue de la Forêt de Haye, 54000, Nancy, France. .,Reference Center for Inborn Errors of Metabolism (ORPHA67872), University Hospital of Nancy, 54000, Nancy, France. .,Department of Molecular Medicine, Division of Biochemistry, Molecular Biology and Nutrition, University Hospital of Nancy, 54000, Nancy, France. .,Department of Hepato-Gastroenterology, University Hospital of Nancy, 54000, Nancy, France.
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El Helou J, Perry TB, Anastasio N, Holbrook KA, Rosenblatt DS. Lessons on the value of long term follow-up from genetic counselling of a family with severe autosomal recessive congenital ichthyosis. Mol Genet Metab 2022; 135:309-310. [PMID: 35216886 DOI: 10.1016/j.ymgme.2022.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 02/11/2022] [Accepted: 02/11/2022] [Indexed: 11/26/2022]
Affiliation(s)
- Janine El Helou
- McGill University, Department of Human Genetics, Montreal, QC, Canada.
| | - Tracy B Perry
- McGill University, Department of Human Genetics, Montreal, QC, Canada
| | - Natascia Anastasio
- University of Sherbrooke, Department of Pediatrics, Sherbrooke, QC, Canada.
| | - Karen A Holbrook
- University of South Florida Sarasota-Manatee Campus, Sarasota, FL, USA.
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Kripps KA, Sremba L, Larson AA, Van Hove JLK, Nguyen H, Wright EL, Mirsky DM, Watkins D, Rosenblatt DS, Ketteridge D, Berry SA, McCandless SE, Baker PR. Methionine synthase deficiency: Variable clinical presentation and benefit of early diagnosis and treatment. J Inherit Metab Dis 2022; 45:157-168. [PMID: 34625984 DOI: 10.1002/jimd.12448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 10/05/2021] [Accepted: 10/06/2021] [Indexed: 11/06/2022]
Abstract
Methionine synthase deficiency (cblG complementation group) is a rare inborn error of metabolism affecting the homocysteine re-methylation pathway. It leads to a biochemical phenotype of hyperhomocysteinemia and hypomethioninemia. The clinical presentation of cblG is variable, ranging from seizures, encephalopathy, macrocytic anemia, hypotonia, and feeding difficulties in the neonatal period to onset of psychiatric symptoms or acute neurologic changes in adolescence or adulthood. Given the variable and nonspecific symptoms seen in cblG, the diagnosis of affected patients is often delayed. Medical management of cblG includes the use of hydroxocobalamin, betaine, folinic acid, and in some cases methionine supplementation. Treatment has been shown to lead to improvement in the biochemical profile of affected patients, with lowering of total homocysteine levels and increasing methionine levels. However, the published literature contains differing conclusions on whether treatment is effective in changing the natural history of the disease. Herein, we present five patients with cblG who have shown substantial clinical benefit from treatment with objective improvement in their neurologic outcomes. We demonstrate more favorable outcomes in our patients who were treated early in life, especially those who were treated before neurologic symptoms manifested. Given improved outcomes from treatment of presymptomatic patients, cblG warrants inclusion in newborn screening.
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Affiliation(s)
- Kimberly A Kripps
- Section of Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, USA
| | - Leighann Sremba
- Section of Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Austin A Larson
- Section of Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Johan L K Van Hove
- Section of Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Hoanh Nguyen
- Section of Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Erica L Wright
- Section of Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - David M Mirsky
- Department of Radiology, University of Colorado, and Children's Hospital Colorado, Aurora, Colorado, USA
| | - David Watkins
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - David Ketteridge
- Department of Genetics and Molecular Pathology, Women's and Children's Hospital, Adelaide, South Australia, Australia
| | - Susan A Berry
- Department of Pediatrics, Division of Genetics and Metabolism, University of Minnesota, Minneapolis, Minnesota, USA
| | - Shawn E McCandless
- Section of Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Peter R Baker
- Section of Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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Pangilinan F, Watkins D, Bernard D, Chen Y, Dong N, Wu Q, Ozel-Abaan H, Kaur M, Caggana M, Morrissey M, Browne ML, Mills JL, Van Ryzin C, Shchelochkov O, Sloan J, Venditti CP, Sarafoglou K, Rosenblatt DS, Kay DM, Brody LC. Probing the functional consequence and clinical relevance of CD320 p.E88del, a variant in the transcobalamin receptor gene. Am J Med Genet A 2022; 188:1124-1141. [PMID: 35107211 DOI: 10.1002/ajmg.a.62627] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/12/2021] [Accepted: 11/20/2021] [Indexed: 11/06/2022]
Abstract
The biological and clinical significance of the p.E88del variant in the transcobalamin receptor, CD320, is unknown. This allele is annotated in ClinVar as likely benign, pathogenic, and of uncertain significance. To determine functional consequence and clinical relevance of this allele, we employed cell culture and genetic association studies. Fibroblasts from 16 CD320 p.E88del homozygotes exhibited reduced binding and uptake of cobalamin. Complete ascertainment of newborns with transiently elevated C3 (propionylcarnitine) in New York State demonstrated that homozygosity for CD320 p.E88del was over-represented (7/348, p < 6 × 10-5 ). Using population data, we estimate that ~85% of the p.E88del homozygotes born in the same period did not have elevated C3, suggesting that cobalamin metabolism in the majority of these infants with this genotype is unaffected. Clinical follow-up of 4/9 homozygous individuals uncovered neuropsychological findings, mostly in speech and language development. None of these nine individuals exhibited perturbation of cobalamin metabolism beyond the newborn stage even during periods of acute illness. Newborns homozygous for this allele in the absence of other factors are at low risk of requiring clinical intervention, although more studies are required to clarify the natural history of various CD320 variants across patient populations.
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Affiliation(s)
- Faith Pangilinan
- Genetics and Environment Interaction Section, National Human Genome Research Institute, National Institutes of Health, Maryland, USA
| | - David Watkins
- Department of Human Genetics, McGill University and Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - David Bernard
- Genetics and Environment Interaction Section, National Human Genome Research Institute, National Institutes of Health, Maryland, USA
| | - Yue Chen
- Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, State Key Laboratory of Radiation Medicine and Prevention, Soochow University, Suzhou, China
| | - Ningzheng Dong
- Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, State Key Laboratory of Radiation Medicine and Prevention, Soochow University, Suzhou, China.,MOH Key Laboratory of Thrombosis and Hemostasis, Jiangsu Institute of Hematology, the First Affiliated Hospital of Soochow University, Suzhou, China
| | - Qingyu Wu
- Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, State Key Laboratory of Radiation Medicine and Prevention, Soochow University, Suzhou, China
| | - Hatice Ozel-Abaan
- Genetics and Environment Interaction Section, National Human Genome Research Institute, National Institutes of Health, Maryland, USA
| | - Manjit Kaur
- Genetics and Environment Interaction Section, National Human Genome Research Institute, National Institutes of Health, Maryland, USA
| | - Michele Caggana
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Mark Morrissey
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Marilyn L Browne
- Birth Defects Registry, New York State Department of Health, Albany, New York and University at Albany School of Public Health, Rensselaer, New York, USA
| | - James L Mills
- Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Carol Van Ryzin
- Organic Acid Research Section, National Human Genome Research Institute, National Institutes of Health, Maryland, USA
| | - Oleg Shchelochkov
- Organic Acid Research Section, National Human Genome Research Institute, National Institutes of Health, Maryland, USA
| | - Jennifer Sloan
- Organic Acid Research Section, National Human Genome Research Institute, National Institutes of Health, Maryland, USA
| | - Charles P Venditti
- Organic Acid Research Section, National Human Genome Research Institute, National Institutes of Health, Maryland, USA
| | - Kyriakie Sarafoglou
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - David S Rosenblatt
- Department of Human Genetics, McGill University and Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.,Division of Medical Biochemistry, Department of Specialized Medicine, McGill University Health Centre, Montreal, Quebec, Canada.,Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, Montreal, Quebec, Canada
| | - Denise M Kay
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Lawrence C Brody
- Genetics and Environment Interaction Section, National Human Genome Research Institute, National Institutes of Health, Maryland, USA
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10
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Chern T, Achilleos A, Tong X, Hill MC, Saltzman AB, Reineke LC, Chaudhury A, Dasgupta SK, Redhead Y, Watkins D, Neilson JR, Thiagarajan P, Green JBA, Malovannaya A, Martin JF, Rosenblatt DS, Poché RA. Mutations in Hcfc1 and Ronin result in an inborn error of cobalamin metabolism and ribosomopathy. Nat Commun 2022; 13:134. [PMID: 35013307 PMCID: PMC8748873 DOI: 10.1038/s41467-021-27759-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 12/13/2021] [Indexed: 12/26/2022] Open
Abstract
Combined methylmalonic acidemia and homocystinuria (cblC) is the most common inborn error of intracellular cobalamin metabolism and due to mutations in Methylmalonic Aciduria type C and Homocystinuria (MMACHC). Recently, mutations in the transcriptional regulators HCFC1 and RONIN (THAP11) were shown to result in cellular phenocopies of cblC. Since HCFC1/RONIN jointly regulate MMACHC, patients with mutations in these factors suffer from reduced MMACHC expression and exhibit a cblC-like disease. However, additional de-regulated genes and the resulting pathophysiology is unknown. Therefore, we have generated mouse models of this disease. In addition to exhibiting loss of Mmachc, metabolic perturbations, and developmental defects previously observed in cblC, we uncovered reduced expression of target genes that encode ribosome protein subunits. We also identified specific phenotypes that we ascribe to deregulation of ribosome biogenesis impacting normal translation during development. These findings identify HCFC1/RONIN as transcriptional regulators of ribosome biogenesis during development and their mutation results in complex syndromes exhibiting aspects of both cblC and ribosomopathies. Combined methylmalonic acidemia (MMA) and hyperhomocysteinemias are inborn errors of vitamin B12 metabolism, and mutations in the transcriptional regulators HCFC1 and RONIN (THAP11) underlie some forms of these disorders. Here the authors generated mouse models of a human syndrome due to mutations in RONIN (THAP11) and HCFC1, and show that this syndrome is both an inborn error of vitamin B12 metabolism and displays some features of ribosomopathy.
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Affiliation(s)
- Tiffany Chern
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA.,Graduate Program in Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Annita Achilleos
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA. .,Department of Basic and Clinical Sciences, University of Nicosia Medical School, Nicosia, Cyprus.
| | - Xuefei Tong
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Matthew C Hill
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA.,Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Alexander B Saltzman
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Lucas C Reineke
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Arindam Chaudhury
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Swapan K Dasgupta
- Department of Pathology, Center for Translational Research on Inflammatory Diseases, Michael E. DeBakey Veterans Affairs Medical Center, Houston, TX, 77030, USA
| | - Yushi Redhead
- The Francis Crick Institute, London, NW1 1AT, UK.,Centre for Craniofacial Biology and Regeneration, King's College London, London, SE1 9RT, UK
| | - David Watkins
- Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, Montreal, QC, Canada.,Division of Medical Biochemistry, Department of Specialized Medicine, McGill University Health Centre, Montreal, QC, Canada
| | - Joel R Neilson
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA.,Graduate Program in Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA.,Development, Disease Models and Therapeutics Graduate Program, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Perumal Thiagarajan
- Department of Pathology, Center for Translational Research on Inflammatory Diseases, Michael E. DeBakey Veterans Affairs Medical Center, Houston, TX, 77030, USA.,Department of Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Jeremy B A Green
- Centre for Craniofacial Biology and Regeneration, King's College London, London, SE1 9RT, UK
| | - Anna Malovannaya
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - James F Martin
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA.,Graduate Program in Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA.,Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, TX, 77030, USA.,Development, Disease Models and Therapeutics Graduate Program, Baylor College of Medicine, Houston, TX, 77030, USA.,Texas Heart Institute, Houston, TX, 77030, USA
| | - David S Rosenblatt
- Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, Montreal, QC, Canada.,Division of Medical Biochemistry, Department of Specialized Medicine, McGill University Health Centre, Montreal, QC, Canada.,Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Ross A Poché
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA. .,Graduate Program in Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, 77030, USA. .,Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, TX, 77030, USA. .,Development, Disease Models and Therapeutics Graduate Program, Baylor College of Medicine, Houston, TX, 77030, USA.
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11
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Abdrabo LS, Watkins D, Wang SR, Lafond-Lapalme J, Riviere JB, Rosenblatt DS. Genome and RNA sequencing in patients with methylmalonic aciduria of unknown cause. Genet Med 2022; 24:254. [PMID: 35029148 DOI: 10.1016/j.gim.2021.11.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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12
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Sorin M, Watkins D, Gilfix BM, Rosenblatt DS. Methionine dependence in tumor cells: The potential role of cobalamin and MMACHC. Mol Genet Metab 2021; 132:155-161. [PMID: 33487542 DOI: 10.1016/j.ymgme.2021.01.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 01/08/2021] [Accepted: 01/08/2021] [Indexed: 12/27/2022]
Abstract
Methionine dependence of tumor cell lines, the inability to grow in tissue culture media lacking methionine but supplemented with homocysteine, has been known for decades, but an understanding of the mechanism underlying this phenomenon remains incomplete. Methionine dependence of certain glioma and melanoma cell lines has been linked to alterations in the metabolism of cobalamin (vitamin B12). In the MeWo LC1 melanoma line, complementation analysis demonstrated that the genetic defect affected the same locus mutated in the cblC inborn error of cobalamin metabolism; hypermethylation of the MMACHC promoter was subsequently demonstrated. Analysis of data in the Cancer Cell Line Encyclopedia showed increased MMACHC methylation levels in melanoma lines compared to other types of cancer. RNA sequencing data from isolated tumors, tabulated at the cBioPortal for Cancer Genomics website, showed decreased MMACHC expression compared to other tumors; and methylation data tabulated at the TGGA Wanderer website demonstrated increased MMACHC methylation. These data suggest that disruptions in cobalamin metabolism might play a more general role in methionine dependence, and potentially in the pathogenesis of melanoma cell lines and primary tumors.
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Affiliation(s)
- Mark Sorin
- Department of Human Genetics, McGill University and Research Institute of the McGill University Health Centre, Montreal, Quebec H4A 3J1, Canada
| | - David Watkins
- Department of Human Genetics, McGill University and Research Institute of the McGill University Health Centre, Montreal, Quebec H4A 3J1, Canada.
| | - Brian M Gilfix
- Division of Medical Biochemistry, Department of Specialized Medicine, McGill University Health Centre, Montreal, Quebec H4A 3J1, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University and Research Institute of the McGill University Health Centre, Montreal, Quebec H4A 3J1, Canada; Division of Medical Biochemistry, Department of Specialized Medicine, McGill University Health Centre, Montreal, Quebec H4A 3J1, Canada; Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, Montreal, Quebec H4A 3J1, Canada
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13
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Bidla G, Rosenblatt DS, Gilfix BM. Identification of Variants in Alpha-1-Antitrypsin by High Resolution Melting. J Appl Lab Med 2020; 6:715-728. [PMID: 33331634 DOI: 10.1093/jalm/jfaa191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 09/28/2020] [Indexed: 11/14/2022]
Abstract
BACKGROUND Alpha-1-antitrypsin deficiency (AATD) is one of the most common hereditary disorders occurring in populations of European origin and is due to variants in SERPINA1, which encodes a protease inhibitor of neutrophil elastase, limiting lung damage from this enzyme. The World Health Organization has recommended that individuals with chronic obstructive pulmonary disease and asthma be tested for AATD. The development of inexpensive and simple genetic testing will help to meet this goal. METHODS Primers and synthetic SERPINA1 gene fragments (gBlocks) were designed for 5 AATD-associated variants. PCR was run on a CFX96 Thermal Cycler with High Resolution Melting (HRM) capacity and data analyzed using the supplied HRM-analysis software. Genomic DNA from individuals (n = 86) genotyped for the S and Z variants were used for validation. HRM-analysis was performed on 3 additional samples with low alpha-1-antitrypsin levels inconsistent with the genotype determined in our clinical laboratory. RESULTS Unique normalized melt curve and difference curve patterns were identified for the AAT variants Z, S, I, F, and MMalton using gBlocks. Similar curve shapes were seen when these primers were used to analyze the gDNA samples. HRM identified the genotypes of the gDNA correctly with 100% concordance. The curve shapes of some samples did not match the melting patterns of the targeted variant. Sequencing was used to identify the variants, including rare AATD variants c.1108_1115delinsAAAAACA (p.Glu370Lysfs*31) and c.1130dup (p.Leu377fs). CONCLUSION We developed a rapid and inexpensive HRM-analysis method for genotyping of Z, S, MMalton, I, and F variants that was also capable of detecting other variants.
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Affiliation(s)
- Gawa Bidla
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada.,Divisions of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, Montreal, Quebec, Canada.,Medical Biochemistry, Department of Specialized Medicine, McGill University Health Centre, Montreal, Quebec, Canada
| | - Brian M Gilfix
- Medical Biochemistry, Department of Specialized Medicine, McGill University Health Centre, Montreal, Quebec, Canada
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14
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Bascunana C, El Helou J, Rauch FT, Bardai G, Glorieux FH, Riviere JB, Byers P, Kaplan PB, Rosenblatt DS. Perspectives on the evolution of genetic counselling: Experience over three decades in a family with recurrent lethal osteogenesis imperfecta. Mol Genet Metab 2020; 131:114-115. [PMID: 32690443 DOI: 10.1016/j.ymgme.2020.06.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 06/23/2020] [Accepted: 06/24/2020] [Indexed: 11/19/2022]
Affiliation(s)
- C Bascunana
- Division of Medical Genetics, Department of Specialized Medicine, Jewish General Hospital, Montreal, Quebec, Canada; Department of Human Genetics, McGill University, Montreal, Quebec, Canada.
| | - J El Helou
- Division of Medical Genetics, Department of Specialized Medicine, Jewish General Hospital, Montreal, Quebec, Canada; Department of Human Genetics, McGill University, Montreal, Quebec, Canada.
| | - F T Rauch
- Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Clinical Biomedical Laboratory, Shriners Hospitals for Children, Montreal, Quebec, Canada.
| | - G Bardai
- Clinical Biomedical Laboratory, Shriners Hospitals for Children, Montreal, Quebec, Canada.
| | - F H Glorieux
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Clinical Biomedical Laboratory, Shriners Hospitals for Children, Montreal, Quebec, Canada.
| | - J-B Riviere
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada.
| | - P Byers
- Departments of Pathology and Medicine (Medical Genetics), University of Washington, Seattle, Washington, USA.
| | - P B Kaplan
- Genetics and Metabolism, The Children's Hospital of Philadelphia, Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
| | - D S Rosenblatt
- Division of Medical Genetics, Department of Specialized Medicine, Jewish General Hospital, Montreal, Quebec, Canada; Department of Human Genetics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics, McGill University, Montreal, Quebec, Canada.
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15
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Abdrabo LS, Watkins D, Wang SR, Lafond-Lapalme J, Riviere JB, Rosenblatt DS. Correction: Genome and RNA sequencing in patients with methylmalonic aciduria of unknown cause. Genet Med 2020; 22:1280. [DOI: 10.1038/s41436-020-0852-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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16
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Bidla G, Watkins D, Chéry C, Froese DS, Ells C, Kerachian M, Saskin A, Christensen KE, Gilfix BM, Guéant JL, Rosenblatt DS. Biochemical analysis of patients with mutations in MTHFD1 and a diagnosis of methylenetetrahydrofolate dehydrogenase 1 deficiency. Mol Genet Metab 2020; 130:179-182. [PMID: 32414565 DOI: 10.1016/j.ymgme.2020.04.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/30/2020] [Accepted: 04/30/2020] [Indexed: 10/24/2022]
Abstract
MTHFD1 is a trifunctional protein containing 10-formyltetrahydrofolate synthetase, 5,10-methenyltetrahydrofolate cyclohydrolase and 5,10-methylenetetrahydrofolate dehydrogenase activities. It is encoded by MTHFD1 and functions in the cytoplasmic folate cycle where it is involved in de novo purine synthesis, synthesis of thymidylate and remethylation of homocysteine to methionine. Since the first reported case of severe combined immunodeficiency resulting from MTHFD1 mutations, seven additional patients ascertained through molecular analysis have been reported with variable phenotypes, including megaloblastic anemia, atypical hemolytic uremic syndrome, hyperhomocysteinemia, microangiopathy, infections and autoimmune diseases. We determined the level of MTHFD1 expression and dehydrogenase specific activity in cell extracts from cultured fibroblasts of three previously reported patients, as well as a patient with megaloblastic anemia and recurrent infections with compound heterozygous MTHFD1 variants that were predicted to be deleterious. MTHFD1 protein expression determined by Western blotting in fibroblast extracts from three of the patients was markedly decreased compared to expression in wild type cells (between 4.8 and 14.3% of mean control values). MTHFD1 expression in the fourth patient was approximately 44% of mean control values. There was no detectable methylenetetrahydrofolate dehydrogenase specific activity in extracts from any of the four patients. This is the first measurement of MTHFD1 function in MTHFD1 deficient patients and confirms the previous molecular diagnoses.
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Affiliation(s)
- Gawa Bidla
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - David Watkins
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada.; Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, Montreal, Quebec, Canada.; Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada..
| | - Céline Chéry
- Inserm-U954, National reference centre for inherited metabolic diseases, University Hospital Centre, Nancy, France
| | - D Sean Froese
- Division of Metabolism and Children's Research Center, University Children's Hospital, Steinwiesstrasse 75, CH-8032 Zürich, Switzerland
| | - Courtney Ells
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Matin Kerachian
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Avi Saskin
- Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, Montreal, Quebec, Canada
| | - Karen E Christensen
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada.; Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Brian M Gilfix
- Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.; Division of Medical Biochemistry, Department of Specialized Medicine, McGill University Health Centre, Montreal, Quebec, Canada
| | - Jean-Louis Guéant
- Inserm-U954, National reference centre for inherited metabolic diseases, University Hospital Centre, Nancy, France
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada.; Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, Montreal, Quebec, Canada.; Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.; Division of Medical Biochemistry, Department of Specialized Medicine, McGill University Health Centre, Montreal, Quebec, Canada
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17
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Abstract
PURPOSE OF REVIEW Immune dysfunction, including severe combined immunodeficiency, has been described in genetic disorders affecting the metabolism of the vitamins cobalamin (vitamin B12) and folate. We have reviewed reports of clinical findings in patients with a number of inborn errors of cobalamin or folate metabolism, specifically looking for immune problems. RECENT FINDINGS There is little evidence that immune function is affected in most of the disorders. Exceptions are Imerslund-Gräsbeck syndrome and hereditary folate malabsorption (affecting intestinal absorption of cobalamin and folate, respectively), transcobalamin deficiency (affecting transport of cobalamin in blood and cellular cobalamin uptake), and methylenetetrahydrofolate dehydrogenase 1 deficiency (catalyzing cytoplasmic interconversion of reduced folate coenzyme derivatives). SUMMARY Although some inborn errors of cobalamin or folate can be associated with immune dysfunction, the degree and type of immune dysfunction vary with no obvious pattern.
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Affiliation(s)
- David Watkins
- Department of Human Genetics, McGill University
- Department of Specialized Medicine, Division of Medical Genetics, McGill University Health Centre
- Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University
- Department of Specialized Medicine, Division of Medical Genetics, McGill University Health Centre
- Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
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18
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Rashka C, Hergalant S, Dreumont N, Oussalah A, Camadro JM, Marchand V, Hassan Z, Baumgartner MR, Rosenblatt DS, Feillet F, Guéant JL, Flayac J, Coelho D. Analysis of fibroblasts from patients with cblC and cblG genetic defects of cobalamin metabolism reveals global dysregulation of alternative splicing. Hum Mol Genet 2020; 29:1969-1985. [DOI: 10.1093/hmg/ddaa027] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 02/10/2020] [Accepted: 02/11/2020] [Indexed: 12/13/2022] Open
Abstract
ABSTRACT
Vitamin B12 or cobalamin (Cbl) metabolism can be affected by genetic defects leading to defective activity of either methylmalonyl-CoA mutase or methionine synthase or both enzymes. Patients usually present with a wide spectrum of pathologies suggesting that various cellular processes could be affected by modifications in gene expression. We have previously demonstrated that these genetic defects are associated with subcellular mislocalization of RNA-binding proteins (RBP) and subsequent altered nucleo-cytoplasmic shuttling of mRNAs. In order to characterize the possible changes of gene expression in these diseases, we have investigated global gene expression in fibroblasts from patients with cblC and cblG inherited disorders by RNA-seq. The most differentially expressed genes are strongly associated with developmental processes, neurological, ophthalmologic and cardiovascular diseases. These associations are consistent with the clinical presentation of cblC and cblG disorders. Multivariate analysis of transcript processing revaled splicing alterations that led to dramatic changes in cytoskeleton organization, response to stress, methylation of macromolecules and RNA binding. The RNA motifs associated with this differential splicing reflected a potential role of RBP such as HuR and HNRNPL. Proteomic analysis confirmed that mRNA processing was significantly disturbed. This study reports a dramatic alteration of gene expression in fibroblasts of patients with cblC and cblG disorders, which resulted partly from disturbed function of RBP. These data suggest to evaluate the rescue of the mislocalization of RBP as a potential strategy in the treatment of severe cases who are resistant to classical treatments with co-enzyme supplements.
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Affiliation(s)
- Charif Rashka
- Inserm UMRS 1256 NGERE – Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy F-54000, France
| | - Sébastien Hergalant
- Inserm UMRS 1256 NGERE – Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy F-54000, France
| | - Natacha Dreumont
- Inserm UMRS 1256 NGERE – Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy F-54000, France
| | - Abderrahim Oussalah
- Inserm UMRS 1256 NGERE – Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy F-54000, France
- National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, Nancy F-54000, France
| | | | - Virginie Marchand
- University of Lorraine, CNRS, INSERM, UMS2008, IBSLor, Epitranscriptomics and RNA Sequencing Core Facility, Nancy F-54000, France
| | - Ziad Hassan
- Inserm UMRS 1256 NGERE – Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy F-54000, France
| | - Matthias R Baumgartner
- Radiz – Rare Disease Initiative Zürich, Clinical Research Priority Program for Rare Diseases, University of Zürich, Zürich, Switzerland
| | | | - François Feillet
- Inserm UMRS 1256 NGERE – Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy F-54000, France
- National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, Nancy F-54000, France
| | - Jean-Louis Guéant
- Inserm UMRS 1256 NGERE – Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy F-54000, France
- National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, Nancy F-54000, France
| | - Justine Flayac
- Inserm UMRS 1256 NGERE – Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy F-54000, France
| | - David Coelho
- Inserm UMRS 1256 NGERE – Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy F-54000, France
- National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, Nancy F-54000, France
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19
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Abdrabo LS, Watkins D, Wang SR, Lafond-Lapalme J, Riviere JB, Rosenblatt DS. Genome and RNA sequencing in patients with methylmalonic
aciduria of unknown cause. Genet Med 2019; 22:432-436. [DOI: 10.1038/s41436-019-0640-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/13/2019] [Indexed: 01/13/2023] Open
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20
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Ruetz M, Campanello GC, McDevitt L, Yokom AL, Yadav PK, Watkins D, Rosenblatt DS, Ohi MD, Southworth DR, Banerjee R. Allosteric Regulation of Oligomerization by a B 12 Trafficking G-Protein Is Corrupted in Methylmalonic Aciduria. Cell Chem Biol 2019; 26:960-969.e4. [PMID: 31056463 DOI: 10.1016/j.chembiol.2019.03.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 03/07/2019] [Accepted: 03/25/2019] [Indexed: 10/26/2022]
Abstract
Allosteric regulation of methylmalonyl-CoA mutase (MCM) by the G-protein chaperone CblA is transduced via three "switch" elements that gate the movement of the B12 cofactor to and from MCM. Mutations in CblA and MCM cause hereditary methylmalonic aciduria. Unlike the bacterial orthologs used previously to model disease-causing mutations, human MCM and CblA exhibit a complex pattern of regulation that involves interconverting oligomers, which are differentially sensitive to the presence of GTP versus GDP. Patient mutations in the switch III region of CblA perturb the nucleotide-sensitive distribution of the oligomeric complexes with MCM, leading to loss of regulated movement of B12 to and/or from MCM and explain the molecular mechanism of the resulting disease.
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Affiliation(s)
- Markus Ruetz
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI, USA
| | - Gregory C Campanello
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI, USA
| | - Liam McDevitt
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI, USA
| | - Adam L Yokom
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Pramod K Yadav
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - David Watkins
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - Melanie D Ohi
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Daniel R Southworth
- Department of Biochemistry and Biophysics, Institute for Neurodegenerative Diseases, University of California-San Francisco, San Francisco, CA 94158, USA
| | - Ruma Banerjee
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI, USA.
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21
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Witte A, Whitehead VM, Rosenblatt DS, Vuchich MJ. Synthesis of Methotrexate Polyglutamates by Bone Marrow Cells
from Patients with Leukemia and Lymphoma. ACTA ACUST UNITED AC 2019. [DOI: 10.1159/000455520] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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22
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Campanello GC, Ruetz M, Dodge GJ, Gouda H, Gupta A, Twahir UT, Killian MM, Watkins D, Rosenblatt DS, Brunold TC, Warncke K, Smith JL, Banerjee R. Sacrificial Cobalt-Carbon Bond Homolysis in Coenzyme B 12 as a Cofactor Conservation Strategy. J Am Chem Soc 2018; 140:13205-13208. [PMID: 30282455 DOI: 10.1021/jacs.8b08659] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A sophisticated intracellular trafficking pathway in humans is used to tailor vitamin B12 into its active cofactor forms, and to deliver it to two known B12-dependent enzymes. Herein, we report an unexpected strategy for cellular retention of B12, an essential and reactive cofactor. If methylmalonyl-CoA mutase is unavailable to accept the coenzyme B12 product of adenosyltransferase, the latter catalyzes homolytic scission of the cobalt-carbon bond in an unconventional reversal of the nucleophilic displacement reaction that was used to make it. The resulting homolysis product binds more tightly to adenosyltransferase than does coenzyme B12, facilitating cofactor retention. We have trapped, and characterized spectroscopically, an intermediate in which the cobalt-carbon bond is weakened prior to being broken. The physiological relevance of this sacrificial catalytic activity for cofactor retention is supported by the significantly lower coenzyme B12 concentration in patients with dysfunctional methylmalonyl-CoA mutase but normal adenosyltransferase activity.
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Affiliation(s)
- Gregory C Campanello
- Department of Biological Chemistry , University of Michigan , Ann Arbor , Michigan 48109-0600 , United States
| | - Markus Ruetz
- Department of Biological Chemistry , University of Michigan , Ann Arbor , Michigan 48109-0600 , United States
| | - Greg J Dodge
- Department of Biological Chemistry , University of Michigan , Ann Arbor , Michigan 48109-0600 , United States.,Life Sciences Institute, University of Michigan , Ann Arbor , Michigan 48109-0600 , United States
| | - Harsha Gouda
- Department of Biological Chemistry , University of Michigan , Ann Arbor , Michigan 48109-0600 , United States.,Indian Institute of Science Education and Research , Pune 411008 , India
| | - Aditi Gupta
- Department of Biological Chemistry , University of Michigan , Ann Arbor , Michigan 48109-0600 , United States
| | - Umar T Twahir
- Department of Physics , Emory University , Atlanta , Georgia 30322-2430 , United States
| | - Michelle M Killian
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States
| | - David Watkins
- Department of Human Genetics , McGill University , Montreal , Quebec H3A 1B1 , Canada
| | - David S Rosenblatt
- Department of Human Genetics , McGill University , Montreal , Quebec H3A 1B1 , Canada
| | - Thomas C Brunold
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States
| | - Kurt Warncke
- Department of Physics , Emory University , Atlanta , Georgia 30322-2430 , United States
| | - Janet L Smith
- Department of Biological Chemistry , University of Michigan , Ann Arbor , Michigan 48109-0600 , United States.,Life Sciences Institute, University of Michigan , Ann Arbor , Michigan 48109-0600 , United States
| | - Ruma Banerjee
- Department of Biological Chemistry , University of Michigan , Ann Arbor , Michigan 48109-0600 , United States
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23
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Guéant JL, Chéry C, Oussalah A, Nadaf J, Coelho D, Josse T, Flayac J, Robert A, Koscinski I, Gastin I, Filhine-Tresarrieu P, Pupavac M, Brebner A, Watkins D, Pastinen T, Montpetit A, Hariri F, Tregouët D, Raby BA, Chung WK, Morange PE, Froese DS, Baumgartner MR, Benoist JF, Ficicioglu C, Marchand V, Motorin Y, Bonnemains C, Feillet F, Majewski J, Rosenblatt DS. Publisher Correction: A PRDX1 mutant allele causes a MMACHC secondary epimutation in cblC patients. Nat Commun 2018; 9:554. [PMID: 29396438 PMCID: PMC5797229 DOI: 10.1038/s41467-018-03054-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The original version of this Article contained an error in the title, which was incorrectly given as 'APRDX1 mutant allele causes a MMACHC secondary epimutation in cblC patients'. This has now been corrected in both the PDF and HTML versions of the Article to read 'A PRDX1 mutant allele causes a MMACHC secondary epimutation in cblC patients'.
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Affiliation(s)
- Jean-Louis Guéant
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France.
| | - Céline Chéry
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Abderrahim Oussalah
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Javad Nadaf
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, H4A 3J1, Montreal, Quebec, Canada
| | - David Coelho
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Thomas Josse
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Justine Flayac
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Aurélie Robert
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Isabelle Koscinski
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Isabelle Gastin
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Pierre Filhine-Tresarrieu
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Mihaela Pupavac
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, H4A 3J1, Montreal, Quebec, Canada
| | - Alison Brebner
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, H4A 3J1, Montreal, Quebec, Canada
| | - David Watkins
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, H4A 3J1, Montreal, Quebec, Canada
| | - Tomi Pastinen
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, H4A 3J1, Montreal, Quebec, Canada
| | - Alexandre Montpetit
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, H4A 3J1, Montreal, Quebec, Canada
| | - Fadi Hariri
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, H4A 3J1, Montreal, Quebec, Canada
| | - David Tregouët
- Sorbonne Universités, UPMC University Paris 06, Institut National pour la Santé et la Recherche Médicale (INSERM), ICAN Institute for Cardiometabolism and Nutrition, Unité Mixte de Recherche en Santé (UMR_S) 1166, Team Genomics & Pathophysiology of Cardiovascular Diseases, 75013, Paris, France
| | - Benjamin A Raby
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 02115, Boston, MA, United States of America
| | - Wendy K Chung
- Departments of Pediatrics and Medicine, Columbia University, 10032, New York, NY, United States of America
| | - Pierre-Emmanuel Morange
- INSERM, UMR_S1062, Nutrition Obesity and Risk of Thrombosis, Aix-Marseille University, 13005, Marseille, France
| | - D Sean Froese
- Division of Metabolism and Children's Research Centre (CRC), University Children's Hospital, CH-8032, Zürich, Switzerland
| | - Matthias R Baumgartner
- Division of Metabolism and Children's Research Centre (CRC), University Children's Hospital, CH-8032, Zürich, Switzerland
| | | | - Can Ficicioglu
- Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, 19104, Philadelphia, PA, United States of America
| | - Virginie Marchand
- Laboratoire Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR7365 CNRS - Université, de Lorraine and FR3209 CNRS- Université de Lorraine, 54505, Nancy, France
| | - Yuri Motorin
- Laboratoire Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR7365 CNRS - Université, de Lorraine and FR3209 CNRS- Université de Lorraine, 54505, Nancy, France
| | - Chrystèle Bonnemains
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - François Feillet
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Jacek Majewski
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, H4A 3J1, Montreal, Quebec, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, H4A 3J1, Montreal, Quebec, Canada
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24
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Quintana AM, Yu HC, Brebner A, Pupavac M, Geiger EA, Watson A, Castro VL, Cheung W, Chen SH, Watkins D, Pastinen T, Skovby F, Appel B, Rosenblatt DS, Shaikh TH. Mutations in THAP11 cause an inborn error of cobalamin metabolism and developmental abnormalities. Hum Mol Genet 2018; 26:2838-2849. [PMID: 28449119 DOI: 10.1093/hmg/ddx157] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 04/20/2017] [Indexed: 11/14/2022] Open
Abstract
CblX (MIM309541) is an X-linked recessive disorder characterized by defects in cobalamin (vitamin B12) metabolism and other developmental defects. Mutations in HCFC1, a transcriptional co-regulator which interacts with multiple transcription factors, have been associated with cblX. HCFC1 regulates cobalamin metabolism via the regulation of MMACHC expression through its interaction with THAP11, a THAP domain-containing transcription factor. The HCFC1/THAP11 complex potentially regulates genes involved in diverse cellular functions including cell cycle, proliferation, and transcription. Thus, it is likely that mutation of THAP11 also results in biochemical and other phenotypes similar to those observed in patients with cblX. We report a patient who presented with clinical and biochemical phenotypic features that overlap cblX, but who does not have any mutations in either MMACHC or HCFC1. We sequenced THAP11 by Sanger sequencing and discovered a potentially pathogenic, homozygous variant, c.240C > G (p.Phe80Leu). Functional analysis in the developing zebrafish embryo demonstrated that both THAP11 and HCFC1 regulate the proliferation and differentiation of neural precursors, suggesting important roles in normal brain development. The loss of THAP11 in zebrafish embryos results in craniofacial abnormalities including the complete loss of Meckel's cartilage, the ceratohyal, and all of the ceratobranchial cartilages. These data are consistent with our previous work that demonstrated a role for HCFC1 in vertebrate craniofacial development. High throughput RNA-sequencing analysis reveals several overlapping gene targets of HCFC1 and THAP11. Thus, both HCFC1 and THAP11 play important roles in the regulation of cobalamin metabolism as well as other pathways involved in early vertebrate development.
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Affiliation(s)
- Anita M Quintana
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Hung-Chun Yu
- Section of Genetics, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Alison Brebner
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - Mihaela Pupavac
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - Elizabeth A Geiger
- Section of Genetics, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Abigail Watson
- Section of Genetics, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Victoria L Castro
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Warren Cheung
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - Shu-Huang Chen
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - David Watkins
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - Tomi Pastinen
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - Flemming Skovby
- Department of Clinical Genetics, Rigshospitalet, and Institute of Clinical Medicine, University of Copenhagen, Copenhagen, 2100 Denmark
| | - Bruce Appel
- Section of Developmental Biology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - Tamim H Shaikh
- Section of Genetics, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
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25
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Guéant JL, Chéry C, Oussalah A, Nadaf J, Coelho D, Josse T, Flayac J, Robert A, Koscinski I, Gastin I, Filhine-Tresarrieu P, Pupavac M, Brebner A, Watkins D, Pastinen T, Montpetit A, Hariri F, Tregouët D, Raby BA, Chung WK, Morange PE, Froese DS, Baumgartner MR, Benoist JF, Ficicioglu C, Marchand V, Motorin Y, Bonnemains C, Feillet F, Majewski J, Rosenblatt DS. APRDX1 mutant allele causes a MMACHC secondary epimutation in cblC patients. Nat Commun 2018; 9:67. [PMID: 29302025 PMCID: PMC5754367 DOI: 10.1038/s41467-017-02306-5] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 11/17/2017] [Indexed: 12/17/2022] Open
Abstract
To date, epimutations reported in man have been somatic and erased in germlines. Here, we identify a cause of the autosomal recessive cblC class of inborn errors of vitamin B12 metabolism that we name “epi-cblC”. The subjects are compound heterozygotes for a genetic mutation and for a promoter epimutation, detected in blood, fibroblasts, and sperm, at the MMACHC locus; 5-azacytidine restores the expression of MMACHC in fibroblasts. MMACHC is flanked by CCDC163P and PRDX1, which are in the opposite orientation. The epimutation is present in three generations and results from PRDX1 mutations that force antisense transcription of MMACHC thereby possibly generating a H3K36me3 mark. The silencing of PRDX1 transcription leads to partial hypomethylation of the epiallele and restores the expression of MMACHC. This example of epi-cblC demonstrates the need to search for compound epigenetic-genetic heterozygosity in patients with typical disease manifestation and genetic heterozygosity in disease-causing genes located in other gene trios. Inborn errors of vitamin B12 metabolism of the cblC class are caused by mutations in the MMACHC gene. Here, Guéant et al. report epi-cblC, a class of cblC in which patients are compound heterozygous for a genetic mutation and a secondary epimutation at the MMACHC locus.
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Affiliation(s)
- Jean-Louis Guéant
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France.
| | - Céline Chéry
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Abderrahim Oussalah
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Javad Nadaf
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, Montreal, H4A 3J1, Quebec, Canada
| | - David Coelho
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Thomas Josse
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Justine Flayac
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Aurélie Robert
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Isabelle Koscinski
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Isabelle Gastin
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Pierre Filhine-Tresarrieu
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Mihaela Pupavac
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, Montreal, H4A 3J1, Quebec, Canada
| | - Alison Brebner
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, Montreal, H4A 3J1, Quebec, Canada
| | - David Watkins
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, Montreal, H4A 3J1, Quebec, Canada
| | - Tomi Pastinen
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, Montreal, H4A 3J1, Quebec, Canada
| | - Alexandre Montpetit
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, Montreal, H4A 3J1, Quebec, Canada
| | - Fadi Hariri
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, Montreal, H4A 3J1, Quebec, Canada
| | - David Tregouët
- Sorbonne Universités, UPMC University Paris 06, Institut National pour la Santé et la Recherche Médicale (INSERM), ICAN Institute for Cardiometabolism and Nutrition, Unité Mixte de Recherche en Santé (UMR_S) 1166, Team Genomics & Pathophysiology of Cardiovascular Diseases, 75013 Paris, France
| | - Benjamin A Raby
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, United States of America
| | - Wendy K Chung
- Departments of Pediatrics and Medicine, Columbia University, New York, NY, 10032, United States of America
| | - Pierre-Emmanuel Morange
- INSERM, UMR_S1062, Nutrition Obesity and Risk of Thrombosis, Aix-Marseille University, 13005, Marseille, France
| | - D Sean Froese
- Division of Metabolism and Children's Research Centre (CRC), University Children's Hospital, CH-8032, Zürich, Switzerland
| | - Matthias R Baumgartner
- Division of Metabolism and Children's Research Centre (CRC), University Children's Hospital, CH-8032, Zürich, Switzerland
| | | | - Can Ficicioglu
- Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, United States of America
| | - Virginie Marchand
- Laboratoire Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR7365 CNRS - Université de Lorraine and FR3209 CNRS- Université de Lorraine, 54505, Nancy, France
| | - Yuri Motorin
- Laboratoire Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR7365 CNRS - Université de Lorraine and FR3209 CNRS- Université de Lorraine, 54505, Nancy, France
| | - Chrystèle Bonnemains
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - François Feillet
- INSERM, UMR_S954 Nutrition-Genetics-Environmental Risk Exposure and Reference Centre of Inborn Metabolism Diseases, University of Lorraine and University Hospital Centre of Nancy (CHRU Nancy), 54505, Nancy, France
| | - Jacek Majewski
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, Montreal, H4A 3J1, Quebec, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University and Research Institute McGill University Health Centre, Montreal, H4A 3J1, Quebec, Canada
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26
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Pupavac M, Zawati MH, Rosenblatt DS. A RaDiCAL gene hunt. J Taibah Univ Med Sci 2017; 12:194-198. [PMID: 31435239 PMCID: PMC6694981 DOI: 10.1016/j.jtumed.2016.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 11/25/2016] [Accepted: 11/29/2016] [Indexed: 11/29/2022] Open
Abstract
In the past several years, rare disease consortia have embarked on the discovery of disease-causing genes for Mendelian diseases using next generation sequencing approaches. Despite the success of these large-scale initiatives, many diseases still have no identified genetic cause. The Rare Disease Collaboration for Autosomal Loci (RaDiCAL) studies the rarest diseases, where occasionally only a single proband is available to identify putative disease-causing genes. This article reviews how “RaDiCAL” addressed some of the challenges in generating informed consent documents for international participants and considers the emerging topic of the “right not to know” in study design.
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Affiliation(s)
- Mihaela Pupavac
- Department of Human Genetics, McGill University, Montreal, Québec, Canada
| | - Ma'n H. Zawati
- Centre of Genomics and Policy, McGill University, Montreal, Québec, Canada
| | - David S. Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Québec, Canada
- Corresponding address: McGill University, Research Institute of the McGill University Health Centre, Glen Site, 1001 Décarie Boulevard Block E, M0.2220, Montreal, Québec, H4A 3J1, Canada.
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27
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Kernohan KD, Dyment DA, Pupavac M, Cramer Z, McBride A, Bernard G, Straub I, Tetreault M, Hartley T, Huang L, Sell E, Majewski J, Rosenblatt DS, Shoubridge E, Mhanni A, Myers T, Proud V, Vergano S, Spangler B, Farrow E, Kussman J, Safina N, Saunders C, Boycott KM, Thiffault I. Matchmaking facilitates the diagnosis of an autosomal-recessive mitochondrial disease caused by biallelic mutation of the tRNA isopentenyltransferase (TRIT1
) gene. Hum Mutat 2017; 38:511-516. [DOI: 10.1002/humu.23196] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 02/07/2017] [Accepted: 02/07/2017] [Indexed: 01/14/2023]
Affiliation(s)
- Kristin D. Kernohan
- Children's Hospital of Eastern Ontario Research Institute; Ottawa Ontario Canada
| | - David A. Dyment
- Children's Hospital of Eastern Ontario Research Institute; Ottawa Ontario Canada
- Department of Genetics; Children's Hospital of Eastern Ontario; Ottawa Ontario Canada
| | - Mihaela Pupavac
- Department of Human Genetics; McGill University; Montréal Québec Canada
| | - Zvi Cramer
- Department of Human Genetics; McGill University; Montréal Québec Canada
| | - Arran McBride
- Children's Hospital of Eastern Ontario Research Institute; Ottawa Ontario Canada
| | - Genevieve Bernard
- Department of Human Genetics; McGill University; Montréal Québec Canada
| | - Isabella Straub
- Department of Human Genetics; McGill University; Montréal Québec Canada
| | - Martine Tetreault
- McGill University and Genome Quebec Innovation Centre; Montreal Quebec Canada
| | - Taila Hartley
- Children's Hospital of Eastern Ontario Research Institute; Ottawa Ontario Canada
| | - Lijia Huang
- Children's Hospital of Eastern Ontario Research Institute; Ottawa Ontario Canada
| | - Erick Sell
- Division of Neurology; Children's Hospital of Eastern Ontario; Ottawa Ontario Canada
| | - Jacek Majewski
- Department of Human Genetics; McGill University; Montréal Québec Canada
- McGill University and Genome Quebec Innovation Centre; Montreal Quebec Canada
| | | | - Eric Shoubridge
- Department of Human Genetics; McGill University; Montréal Québec Canada
| | - Aziz Mhanni
- Section of Genetics and Metabolism; Children's Hospital and the Department of Pediatrics and Child Health; University of Manitoba; Winnipeg Manitoba Canada
| | - Tara Myers
- Department of Pediatrics; Children's Mercy Hospitals; Kansas City Missouri
| | - Virginia Proud
- Division of Medical Genetics and Metabolism; Children's Hospital of the King's Daughters; Norfolk Virginia
| | - Samanta Vergano
- Division of Medical Genetics and Metabolism; Children's Hospital of the King's Daughters; Norfolk Virginia
| | - Brooke Spangler
- Division of Medical Genetics and Metabolism; Children's Hospital of the King's Daughters; Norfolk Virginia
| | - Emily Farrow
- Center for Pediatric Genomic Medicine; Children's Mercy Hospital; Kansas City Missouri
- University of Missouri-Kansas City School of Medicine; Kansas City Missouri
| | - Jennifer Kussman
- Department of Pediatrics; Children's Mercy Hospitals; Kansas City Missouri
| | - Nicole Safina
- Department of Pediatrics; Children's Mercy Hospitals; Kansas City Missouri
| | - Carol Saunders
- Center for Pediatric Genomic Medicine; Children's Mercy Hospital; Kansas City Missouri
- University of Missouri-Kansas City School of Medicine; Kansas City Missouri
| | - Kym M. Boycott
- Children's Hospital of Eastern Ontario Research Institute; Ottawa Ontario Canada
- Department of Genetics; Children's Hospital of Eastern Ontario; Ottawa Ontario Canada
| | - Isabelle Thiffault
- Center for Pediatric Genomic Medicine; Children's Mercy Hospital; Kansas City Missouri
- University of Missouri-Kansas City School of Medicine; Kansas City Missouri
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28
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Chu J, Pupavac M, Watkins D, Tian X, Feng Y, Chen S, Fenter R, Zhang VW, Wang J, Wong LJ, Rosenblatt DS. Corrigendum to "Next generation sequencing of patients with mut methylmalonic aciduria: Validation of somatic cell studies and identification of 16 novel mutations." [Mol. Genet. Metab. (Aug 2016); 118(4): 264-71]. Mol Genet Metab 2017; 120:295. [PMID: 28284539 DOI: 10.1016/j.ymgme.2016.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Jordan Chu
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Mihaela Pupavac
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - David Watkins
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Xia Tian
- Department of Molecular Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Yanming Feng
- Department of Molecular Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Stella Chen
- Department of Molecular Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Remington Fenter
- Department of Molecular Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Victor W Zhang
- Department of Molecular Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Jing Wang
- Department of Molecular Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Lee-Jun Wong
- Department of Molecular Genetics, Baylor College of Medicine, Houston, TX, United States
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada.
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Waters PJ, Thuriot F, Clarke JT, Gravel S, Watkins D, Rosenblatt DS, Lévesque S. Methylmalonyl-coA epimerase deficiency: A new case, with an acute metabolic presentation and an intronic splicing mutation in the MCEE gene. Mol Genet Metab Rep 2016; 9:19-24. [PMID: 27699154 PMCID: PMC5037260 DOI: 10.1016/j.ymgmr.2016.09.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 09/02/2016] [Accepted: 09/03/2016] [Indexed: 11/27/2022] Open
Abstract
Methylmalonyl-coA epimerase (MCE) follows propionyl-coA carboxylase and precedes methylmalonyl-coA mutase in the pathway converting propionyl-coA to succinyl-coA. MCE deficiency has previously been described in six patients, one presenting with metabolic acidosis, the others with nonspecific neurological symptoms or asymptomatic. The clinical significance and biochemical characteristics of this rare condition have been incompletely defined. We now describe a patient who presented acutely at 5 years of age with vomiting, dehydration, confusion, severe metabolic acidosis and mild hyperammonemia. At presentation, organic acid profiles were dominated by increased ketones and 3-hydroxypropionate, with moderately elevated methylcitrate and propionylglycine, and acylcarnitine profiles showed marked C3 (propionylcarnitine) elevation with normal C4DC (methylmalonylcarnitine + succinylcarnitine). Propionic acidemia was initially suspected, but it was subsequently noted that methylmalonic acid was mildly but persistently elevated in urine, and clearly elevated in plasma and cerebrospinal fluid. The overall biochemical profile prompted consideration of MCE deficiency. Studies on cultured fibroblasts showed moderately decreased propionate incorporation. Complementation analysis permitted assignment to the MCEE group. A heterozygous p.Arg47Ter (p.R47*) mutation in the MCEE gene was identified by sequencing of exons, and RNA studies identified a novel intronic splicing mutation, c.379-644A > G, confirming the diagnosis of MCE deficiency. Following the initial severe presentation, development has been normal and the clinical course over the subsequent six years has remained relatively uneventful on an essentially normal diet. This report contributes to the clinical and biochemical characterisation of this rare disorder, while highlighting potential causes of under-diagnosis or of diagnostic confusion.
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Affiliation(s)
- Paula J. Waters
- Medical Genetics Service, Department of Pediatrics, Centre hospitalier universitaire de Sherbrooke (CHUS) and University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Fanny Thuriot
- Medical Genetics Service, Department of Pediatrics, Centre hospitalier universitaire de Sherbrooke (CHUS) and University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Joe T.R. Clarke
- Medical Genetics Service, Department of Pediatrics, Centre hospitalier universitaire de Sherbrooke (CHUS) and University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Serge Gravel
- Medical Genetics Service, Department of Pediatrics, Centre hospitalier universitaire de Sherbrooke (CHUS) and University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - David Watkins
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | | | - Sébastien Lévesque
- Medical Genetics Service, Department of Pediatrics, Centre hospitalier universitaire de Sherbrooke (CHUS) and University of Sherbrooke, Sherbrooke, Quebec, Canada
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Chu J, Pupavac M, Watkins D, Tian X, Feng Y, Chen S, Fenter R, Zhang VW, Wang J, Wong LJ, Rosenblatt DS. Next generation sequencing of patients with mut methylmalonic aciduria: Validation of somatic cell studies and identification of 16 novel mutations. Mol Genet Metab 2016; 118:264-71. [PMID: 27233228 DOI: 10.1016/j.ymgme.2016.05.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 05/18/2016] [Accepted: 05/18/2016] [Indexed: 12/13/2022]
Abstract
Mutations in the MUT gene, which encodes the mitochondrial enzyme methylmalonyl-CoA mutase, are responsible for the mut form of methylmalonic aciduria (MMA). In this study, a next generation sequencing (NGS) based gene panel was used to analyze 53 patients that had been diagnosed with mut MMA by somatic cell complementation analysis. A total of 54 different mutations in MUT were identified in 48 patients; 16 novel mutations were identified, including 1 initiation site mutation (c.2T>C [p.M1?]), 1 missense mutation (c.566A>T [p.N189I]), 2 nonsense mutations (c.129G>A [p.W43*] and c.1975C>T [p.Q659*]), 2 mutations affecting splice sites (c.753+3A>G and c.754-2A>G), 8 small insertions, deletions, and duplications (c.29dupT [p.L10Ffs*39], c.55dupG [p.V19Gfs*30], c.631_633delGAG [p.E211del], c.795_796insT [p.M266Yfs*7], c.1061delCinsGGA [p.S354Wfs*20], c.1065_1068dupATGG [p.S357Mfs*5], c.1181dupT [p.L394Ffs*30], c.1240delG [p.E414Kfs*17]), a large insertion (c.146_147ins279), and a large deletion involving exon 13. Phenotypic rescue and cDNA analysis were used to confirm that the c.146_147ins279 and c.631_633delGAG mutations were associated with the decreased methylmalonyl-CoA mutase function observed in the patient fibroblasts. In five patients, the NGS panel did not confirm the diagnosis made by complementation analysis. One of these patients was found to carry 2 novel mutations (c.433G > A [p.E145K] and c.511A>C [p.N171H]) in the SUCLG1 gene.
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Affiliation(s)
- Jordan Chu
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Mihaela Pupavac
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - David Watkins
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Xia Tian
- Department of Molecular Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Yanming Feng
- Department of Molecular Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Stella Chen
- Department of Molecular Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Remington Fenter
- Department of Molecular Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Victor W Zhang
- Department of Molecular Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Jing Wang
- Department of Molecular Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Lee-Jun Wong
- Department of Molecular Genetics, Baylor College of Medicine, Houston, TX, United States
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada.
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Pupavac M, Watkins D, Petrella F, Fahiminiya S, Janer A, Cheung W, Gingras AC, Pastinen T, Muenzer J, Majewski J, Shoubridge EA, Rosenblatt DS. Inborn Error of Cobalamin Metabolism Associated with the Intracellular Accumulation of Transcobalamin-Bound Cobalamin and Mutations in ZNF143, Which Codes for a Transcriptional Activator. Hum Mutat 2016; 37:976-82. [PMID: 27349184 DOI: 10.1002/humu.23037] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 06/09/2016] [Accepted: 06/17/2016] [Indexed: 11/09/2022]
Abstract
Vitamin B12 (cobalamin, Cbl) cofactors adenosylcobalamin (AdoCbl) and methylcobalamin (MeCbl) are required for the activity of the enzymes methylmalonyl-CoA mutase (MCM) and methionine synthase (MS). Inborn errors of Cbl metabolism are rare Mendelian disorders associated with hematological and neurological manifestations, and elevations of methylmalonic acid and/or homocysteine in the blood and urine. We describe a patient whose fibroblasts had decreased functional activity of MCM and MS and decreased synthesis of AdoCbl and MeCbl (3.4% and 1.0% of cellular Cbl, respectively). The defect in cultured patient fibroblasts complemented those from all known complementation groups. Patient cells accumulated transcobalamin-bound-Cbl, a complex which usually dissociates in the lysosome to release free Cbl. Whole-exome sequencing identified putative disease-causing variants c.851T>G (p.L284*) and c.1019C>T (p.T340I) in transcription factor ZNF143. Proximity biotinylation analysis confirmed the interaction between ZNF143 and HCFC1, a protein that regulates expression of the Cbl trafficking enzyme MMACHC. qRT-PCR analysis revealed low MMACHC expression levels both in patient fibroblasts, and in control fibroblasts incubated with ZNF143 siRNA.
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Affiliation(s)
- Mihaela Pupavac
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - David Watkins
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Francis Petrella
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Somayyeh Fahiminiya
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada.,McGill University and Genome Quebec Innovation Centre, Montreal, Quebec, Canada
| | - Alexandre Janer
- Montreal Neurological Institute and Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Warren Cheung
- McGill University and Genome Quebec Innovation Centre, Montreal, Quebec, Canada
| | - Anne-Claude Gingras
- Lunenfeld-Tanenbaum Research Institute at Sinai Health System and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Tomi Pastinen
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada.,McGill University and Genome Quebec Innovation Centre, Montreal, Quebec, Canada
| | - Joseph Muenzer
- University of North Carolina, Chapel Hill, North Carolina, USA
| | - Jacek Majewski
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada.,McGill University and Genome Quebec Innovation Centre, Montreal, Quebec, Canada
| | - Eric A Shoubridge
- Montreal Neurological Institute and Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
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Mah W, Sonkusare SK, Wang T, Azeddine B, Pupavac M, Carrot-Zhang J, Hong K, Majewski J, Harvey EJ, Russell L, Chalk C, Rosenblatt DS, Nelson MT, Séguin C. Gain-of-function mutation in TRPV4 identified in patients with osteonecrosis of the femoral head. J Med Genet 2016; 53:705-9. [PMID: 27330106 PMCID: PMC5035228 DOI: 10.1136/jmedgenet-2016-103829] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 05/25/2016] [Indexed: 12/11/2022]
Abstract
Background Osteonecrosis of the femoral head is a debilitating disease that involves impaired blood supply to the femoral head and leads to femoral head collapse. Methods We use whole-exome sequencing and Sanger sequencing to analyse a family with inherited osteonecrosis of the femoral head and fluorescent Ca2+ imaging to functionally characterise the variant protein. Results We report a family with four siblings affected with inherited osteonecrosis of the femoral head and the identification of a c.2480_2483delCCCG frameshift deletion followed by a c.2486T>A substitution in one allele of the transient receptor potential vanilloid 4 (TRPV4) gene. TRPV4 encodes a Ca2+-permeable cation channel known to play a role in vasoregulation and osteoclast differentiation. While pathogenic TRPV4 mutations affect the skeletal or nervous systems, association with osteonecrosis of the femoral head is novel. Functional measurements of Ca2+ influx through mutant TRPV4 channels in HEK293 cells and patient-derived dermal fibroblasts identified a TRPV4 gain of function. Analysis of channel open times, determined indirectly from measurement of TRPV4 activity within a cluster of TRPV4 channels, revealed that the TRPV4 gain of function was caused by longer channel openings. Conclusions These findings identify a novel TRPV4 mutation implicating TRPV4 and altered calcium homeostasis in the pathogenesis of osteonecrosis while reinforcing the importance of TRPV4 in bone diseases and vascular endothelium.
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Affiliation(s)
- Wayne Mah
- Division of Hematology and Oncology, Department of Medicine, McGill University Health Centre, Montreal, Quebec, Canada
| | - Swapnil K Sonkusare
- Department of Pharmacology, University of Vermont, Burlington, Vermont, USA Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
| | - Tracy Wang
- Division of Hematology and Oncology, Department of Medicine, McGill University Health Centre, Montreal, Quebec, Canada
| | - Bouziane Azeddine
- Division of Hematology and Oncology, Department of Medicine, McGill University Health Centre, Montreal, Quebec, Canada
| | - Mihaela Pupavac
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Jian Carrot-Zhang
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada Department of Human Genetics, McGill University and Genome Québec Innovation Centre, Montreal, Quebec, Canada
| | - Kwangseok Hong
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
| | - Jacek Majewski
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada Department of Human Genetics, McGill University and Genome Québec Innovation Centre, Montreal, Quebec, Canada
| | - Edward J Harvey
- Department of Surgery, Division of Orthopaedic Surgery, McGill University Health Centre, Montreal, Quebec, Canada
| | - Laura Russell
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Colin Chalk
- Department of Neurology & Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Mark T Nelson
- Department of Pharmacology, University of Vermont, Burlington, Vermont, USA Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | - Chantal Séguin
- Division of Hematology and Oncology, Department of Medicine, McGill University Health Centre, Montreal, Quebec, Canada
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Gupta S, Fahiminiya S, Wang T, Dempsey Nunez L, Rosenblatt DS, Gibson WT, Gilfix B, Bergeron JJM, Jerome-Majewska LA. Somatic overgrowth associated with homozygous mutations in both MAN1B1 and SEC23A. Cold Spring Harb Mol Case Stud 2016; 2:a000737. [PMID: 27148587 PMCID: PMC4853519 DOI: 10.1101/mcs.a000737] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Using whole-exome sequencing, we identified homozygous mutations in two unlinked genes, SEC23A c.1200G>C (p.M400I) and MAN1B1 c.1000C>T (p.R334C), associated with congenital birth defects in two patients from a consanguineous family. Patients presented with carbohydrate-deficient transferrin, tall stature, obesity, macrocephaly, and maloccluded teeth. The parents were healthy heterozygous carriers for both mutations and an unaffected sibling with tall stature carried the heterozygous mutation in SEC23A only. Mutations in SEC23A are responsible for craniolenticosultura dysplasia (CLSD). CLSD patients are short, have late-closing fontanels, and have reduced procollagen (pro-COL1A1) secretion because of abnormal pro-COL1A1 retention in the endoplasmic reticulum (ER). The mutation we identified in MAN1B1 was previously associated with reduced MAN1B1 protein and congenital disorders of glycosylation (CDG). CDG patients are also short, are obese, and have abnormal glycan remodeling. Molecular analysis of fibroblasts from the family revealed normal levels of SEC23A in all cells and reduced levels of MAN1B1 in cells with heterozygous or homozygous mutations in SEC23A and MAN1B1. Secretion of pro-COL1A1 was increased in fibroblasts from the siblings and patients, and pro-COL1A1 was retained in Golgi of heterozygous and homozygous mutant cells, although intracellular pro-COL1A1 was increased in patient fibroblasts only. We postulate that increased pro-COL1A1 secretion is responsible for tall stature in these patients and an unaffected sibling, and not previously discovered in patients with mutations in either SEC23A or MAN1B1. The patients in this study share biochemical and cellular characteristics consistent with mutations in MAN1B1 and SEC23A, indicating a digenic disease.
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Affiliation(s)
- Swati Gupta
- Department of Human Genetics, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - Somayyeh Fahiminiya
- Department of Human Genetics, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - Tracy Wang
- Department of Human Genetics, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - Laura Dempsey Nunez
- Department of Human Genetics, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Quebec H3A 1B1, Canada;; Department of Pediatrics, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - William T Gibson
- Department of Medical Genetics, Child and Family Research Institute, Vancouver, British Columbia V6H 3V4, Canada
| | - Brian Gilfix
- Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - John J M Bergeron
- Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Loydie A Jerome-Majewska
- Department of Human Genetics, McGill University, Montreal, Quebec H3A 1B1, Canada;; Department of Pediatrics, McGill University, Montreal, Quebec H4A 3J1, Canada;; Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada
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Pupavac M, Tian X, Chu J, Wang G, Feng Y, Chen S, Fenter R, Zhang VW, Wang J, Watkins D, Wong LJ, Rosenblatt DS. Added value of next generation gene panel analysis for patients with elevated methylmalonic acid and no clinical diagnosis following functional studies of vitamin B12 metabolism. Mol Genet Metab 2016; 117:363-8. [PMID: 26827111 DOI: 10.1016/j.ymgme.2016.01.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 01/22/2016] [Indexed: 12/13/2022]
Abstract
Next generation sequencing (NGS) based gene panel testing is increasingly available as a molecular diagnostic approach for inborn errors of metabolism. Over the past 40 years patients have been referred to the Vitamin B12 Clinical Research Laboratory at McGill University for diagnosis of inborn errors of cobalamin metabolism by functional studies in cultured fibroblasts. DNA samples from patients in which no diagnosis was made by these studies were tested by a NGS gene panel to determine whether any molecular diagnoses could be made. 131 DNA samples from patients with elevated methylmalonic acid and no diagnosis following functional studies of cobalamin metabolism were analyzed using the 24 gene extended cobalamin metabolism NGS based panel developed by Baylor Miraca Genetics Laboratories. Gene panel testing identified two or more variants in a single gene in 16/131 patients. Eight patients had pathogenic findings, one had a finding of uncertain significance, and seven had benign findings. Of the patients with pathogenic findings, five had mutations in ACSF3, two in SUCLG1 and one in TCN2. Thus, the NGS gene panel allowed for the presumptive diagnosis of 8 additional patients for which a diagnosis was not made by the functional assays.
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Affiliation(s)
- Mihaela Pupavac
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Xia Tian
- Baylor Miraca Genetics Laboratories, Houston, TX, United States
| | - Jordan Chu
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Guoli Wang
- Baylor Miraca Genetics Laboratories, Houston, TX, United States
| | - Yanming Feng
- Baylor Miraca Genetics Laboratories, Houston, TX, United States
| | - Stella Chen
- Baylor Miraca Genetics Laboratories, Houston, TX, United States
| | | | - Victor W Zhang
- Baylor Miraca Genetics Laboratories, Houston, TX, United States; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Jing Wang
- Baylor Miraca Genetics Laboratories, Houston, TX, United States; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - David Watkins
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Lee-Jun Wong
- Baylor Miraca Genetics Laboratories, Houston, TX, United States; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada.
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Field MS, Kamynina E, Watkins D, Rosenblatt DS, Stover PJ. New insights into the metabolic and nutritional determinants of severe combined immunodeficiency. Rare Dis 2015; 3:e1112479. [PMID: 27123375 PMCID: PMC4817835 DOI: 10.1080/21675511.2015.1112479] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 09/20/2015] [Accepted: 10/19/2015] [Indexed: 11/07/2022] Open
Abstract
Human mutations in MTHFD1 have recently been identified in patients with severe
combined immunodeficiency (SCID). SCID results from inborn errors of metabolism
that cause impaired T- and B-cell proliferation and function. One of the most
common causes of SCID is adenosine deaminase (ADA) deficiency, which ultimately
inhibits DNA synthesis and cell division. MTHFD1 has been shown to translocate
to the nucleus during S-phase of the cell cycle; this localization is critical
for synthesis of thymidyate (dTMP or the “T” base in DNA) and
subsequent progression through the cell cycle and cell proliferation.
Identification of MTHFD1 mutations that are associated with
SCID highlights the potential importance of adequate dTMP synthesis in the
etiology of SCID.
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Affiliation(s)
- Martha S Field
- Division of Nutritional Sciences; Cornell University ; Ithaca, NY USA
| | - Elena Kamynina
- Division of Nutritional Sciences; Cornell University ; Ithaca, NY USA
| | - David Watkins
- Department of Human Genetics, McGill University; Department of Medical Genetics; McGill University Health Center ; Montreal, Quebec, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University; Department of Medical Genetics; McGill University Health Center ; Montreal, Quebec, Canada
| | - Patrick J Stover
- Division of Nutritional Sciences; Cornell University; Ithaca, NY USA; Graduate Field of Biochemistry; Molecular and Cell Biology; Cornell University; Ithaca, NY USA
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Burda P, Kuster A, Hjalmarson O, Suormala T, Bürer C, Lutz S, Roussey G, Christa L, Asin-Cayuela J, Kollberg G, Andersson BA, Watkins D, Rosenblatt DS, Fowler B, Holme E, Froese DS, Baumgartner MR. Characterization and review of MTHFD1 deficiency: four new patients, cellular delineation and response to folic and folinic acid treatment. J Inherit Metab Dis 2015; 38:863-72. [PMID: 25633902 DOI: 10.1007/s10545-015-9810-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 12/15/2014] [Accepted: 01/06/2015] [Indexed: 01/15/2023]
Abstract
In the folate cycle MTHFD1, encoded by MTHFD1, is a trifunctional enzyme containing 5,10-methylenetetrahydrofolate dehydrogenase, 5,10-methenyltetrahydrofolate cyclohydrolase and 10-formyltetrahydrofolate synthetase activity. To date, only one patient with MTHFD1 deficiency, presenting with hyperhomocysteinemia, megaloblastic anaemia, hemolytic uremic syndrome (HUS) and severe combined immunodeficiency, has been identified (Watkins et al J Med Genet 48:590-2, 2011). We now describe four additional patients from two different families. The second patient presented with hyperhomocysteinemia, megaloblastic anaemia, HUS, microangiopathy and retinopathy; all except the retinopathy resolved after treatment with hydroxocobalamin, betaine and folinic acid. The third patient developed megaloblastic anaemia, infection, autoimmune disease and moderate liver fibrosis but not hyperhomocysteinemia, and was successfully treated with a regime that included and was eventually reduced to folic acid. The other two, elder siblings of the third patient, died at 9 weeks of age with megaloblastic anaemia, infection and severe acidosis and had MTFHD1 deficiency diagnosed retrospectively. We identified a missense mutation (c.806C > T, p.Thr296Ile) and a splice site mutation (c.1674G > A) leading to exon skipping in the second patient, while the other three harboured a missense mutation (c.146C > T, p.Ser49Phe) and a premature stop mutation (c.673G > T, p.Glu225*), all of which were novel. Patient fibroblast studies revealed severely reduced methionine formation from [(14)C]-formate, which did not increase in cobalamin supplemented culture medium but was responsive to folic and folinic acid. These additional cases increase the clinical spectrum of this intriguing defect, provide in vitro evidence of disturbed methionine synthesis and substantiate the effectiveness of folic or folinic acid treatment.
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Affiliation(s)
- P Burda
- Division of Metabolism and Children's Research Center, University Children's Hospital, Steinwiesstrasse 75, 8032, Zurich, Switzerland
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Deme JC, Hancock MA, Xia X, Shintre CA, Plesa M, Kim JC, Carpenter EP, Rosenblatt DS, Coulton JW. Purification and interaction analyses of two human lysosomal vitamin B12transporters: LMBD1 and ABCD4. Mol Membr Biol 2014; 31:250-61. [DOI: 10.3109/09687688.2014.990998] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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38
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Awan Z, Aljenedil S, Rosenblatt DS, Cusson J, Gilfix BM, Genest J. Severe hyperhomocysteinemia due to cystathionine β-synthase deficiency, and Factor V Leiden mutation in a patient with recurrent venous thrombosis. Thromb J 2014; 12:30. [PMID: 25516723 PMCID: PMC4266910 DOI: 10.1186/s12959-014-0030-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 11/04/2014] [Indexed: 11/10/2022] Open
Abstract
Homocysteine is an amino acid that is toxic to vascular endothelial cells, and plasma elevations have been associated with venous thromboembolism. Severe hyperhomocysteinemia (>100 μmol/L) may result from mutations in the genes coding for enzymes in the trans-sulfuration or the folate/vitamin B12-dependent re-methylation pathways. Here, we report the case of a young woman with severe, recurrent thrombo-embolic events associated with severe hyperhomocysteinemia (111 μmol/L). We identified a homozygous mutation in the cystathionine β -synthase gene (p.I278T) and the presence of the Factor V Leiden mutation. Family study shows segregation of elevated homocysteine in heterozygous relatives for the mutation in the cystathionine β -synthase gene. Management consisted of anticoagulation with warfarin and supplementation with folate, vitamin B6 (pyridoxine) and vitamin B12. After twelve years of follow-up, plasma homocysteine levels remain in the moderate range (~20 μmol/L, reference range 8-12 μmol/L) and no further thromboembolic events were identified.
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Affiliation(s)
- Zuhier Awan
- King Abdulaziz University, Jeddah, Saudi Arabia
| | | | | | - Jean Cusson
- Department of Medicine, Université de Sherbrooke, Sherbrooke, Canada
| | | | - Jacques Genest
- The McGill University Health Centre, Montreal, Canada ; Royal Victoria Hospital, 687 Pine Avenue West, Rm M4.72, Montreal, QC H3A 1A1 Canada
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Quintana AM, Geiger EA, Achilly N, Rosenblatt DS, Maclean KN, Stabler SP, Artinger KB, Appel B, Shaikh TH. Hcfc1b, a zebrafish ortholog of HCFC1, regulates craniofacial development by modulating mmachc expression. Dev Biol 2014; 396:94-106. [PMID: 25281006 DOI: 10.1016/j.ydbio.2014.09.026] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 09/24/2014] [Indexed: 12/01/2022]
Abstract
Mutations in HCFC1 (MIM300019), have been recently associated with cblX (MIM309541), an X-linked, recessive disorder characterized by multiple congenital anomalies including craniofacial abnormalities. HCFC1 is a transcriptional co-regulator that modulates the expression of numerous downstream target genes including MMACHC, but it is not clear how these HCFC1 targets play a role in the clinical manifestations of cblX. To begin to elucidate the mechanism by which HCFC1 modulates disease phenotypes, we have carried out loss of function analyses in the developing zebrafish. Of the two HCFC1 orthologs in zebrafish, hcfc1a and hcfc1b, the loss of hcfc1b specifically results in defects in craniofacial development. Subsequent analysis revealed that hcfc1b regulates cranial neural crest cell differentiation and proliferation within the posterior pharyngeal arches. Further, the hcfc1b-mediated craniofacial abnormalities were rescued by expression of human MMACHC, a downstream target of HCFC1 that is aberrantly expressed in cblX. Furthermore, we tested distinct human HCFC1 mutations for their role in craniofacial development and demonstrated variable effects on MMACHC expression in humans and craniofacial development in zebrafish. Notably, several individuals with mutations in either HCFC1 or MMACHC have been reported to have mild to moderate facial dysmorphia. Thus, our data demonstrates that HCFC1 plays a role in craniofacial development, which is in part mediated through the regulation of MMACHC expression.
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Affiliation(s)
- Anita M Quintana
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA.
| | - Elizabeth A Geiger
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA.
| | - Nate Achilly
- Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada H3A 1B1.
| | - Kenneth N Maclean
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA; Section of Genetics, University of Colorado, School of Medicine, Aurora, CO 80045, USA.
| | - Sally P Stabler
- Department of Medicine, University of Colorado School of Medicine, CO 80045, USA.
| | - Kristin B Artinger
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado, CO 80045, USA.
| | - Bruce Appel
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA.
| | - Tamim H Shaikh
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA; Section of Genetics, University of Colorado, School of Medicine, Aurora, CO 80045, USA.
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Lossos A, Teltsh O, Milman T, Meiner V, Rozen R, Leclerc D, Schwahn BC, Karp N, Rosenblatt DS, Watkins D, Shaag A, Korman SH, Heyman SN, Gal A, Newman JP, Steiner-Birmanns B, Abramsky O, Kohn Y. Severe methylenetetrahydrofolate reductase deficiency: clinical clues to a potentially treatable cause of adult-onset hereditary spastic paraplegia. JAMA Neurol 2014; 71:901-4. [PMID: 24797679 DOI: 10.1001/jamaneurol.2014.116] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
IMPORTANCE Hereditary spastic paraplegia is a highly heterogeneous group of neurogenetic disorders with pure and complicated clinical phenotypes. No treatment is available for these disorders. We identified 2 unrelated families, each with 2 siblings with severe methylenetetrahydrofolate reductase (MTHFR) deficiency manifesting a complicated form of adult-onset hereditary spastic paraparesis partially responsive to betaine therapy. OBSERVATIONS Both pairs of siblings presented with a similar combination of progressive spastic paraparesis and polyneuropathy, variably associated with behavioral changes, cognitive impairment, psychosis, seizures, and leukoencephalopathy, beginning between the ages of 29 and 50 years. By the time of diagnosis a decade later, 3 patients were ambulatory and 1 was bedridden. Investigations have revealed severe hyperhomocysteinemia and hypomethioninemia, reduced fibroblast MTHFR enzymatic activity (18%-52% of control participants), and 3 novel pathogenic MTHFR mutations, 2 as compound heterozygotes in one family and 1 as a homozygous mutation in the other family. Treatment with betaine produced a rapid decline of homocysteine by 50% to 70% in all 4 patients and, over 9 to 15 years, improved the conditions of the 3 ambulatory patients. CONCLUSIONS AND RELEVANCE Although severe MTHFR deficiency is a rare cause of complicated spastic paraparesis in adults, it should be considered in select patients because of the potential therapeutic benefit of betaine supplementation.
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Affiliation(s)
- Alexander Lossos
- Center for Human Neurogenetics, Department of Neurology and Agnes Ginges, Hebrew University-Hadassah Medical Center, Jerusalem, Israel
| | - Omri Teltsh
- Hebrew University-Hadassah School of Medicine, Jerusalem, Israel3National Institute for Biotechnology in the Negev, Ben Gurion University, Beer Sheva, Israel
| | - Tsipi Milman
- Hebrew University-Hadassah School of Medicine, Jerusalem, Israel
| | - Vardiella Meiner
- Department of Genetics, Hebrew University-Hadassah Medical Center, Jerusalem, Israel5Department of Metabolic Diseases, Hebrew University-Hadassah Medical Center, Jerusalem, Israel
| | - Rima Rozen
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada7Department of Pediatrics, McGill University, Montreal, Quebec, Canada
| | - Daniel Leclerc
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada7Department of Pediatrics, McGill University, Montreal, Quebec, Canada
| | - Bernd C Schwahn
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada7Department of Pediatrics, McGill University, Montreal, Quebec, Canada
| | - Natalya Karp
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada7Department of Pediatrics, McGill University, Montreal, Quebec, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada7Department of Pediatrics, McGill University, Montreal, Quebec, Canada8Department of Medicine, McGill University, Montreal, Quebec, Canada9Department of Biology, McGill University, M
| | - David Watkins
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Avraham Shaag
- Department of Genetics, Hebrew University-Hadassah Medical Center, Jerusalem, Israel5Department of Metabolic Diseases, Hebrew University-Hadassah Medical Center, Jerusalem, Israel
| | - Stanley H Korman
- Department of Genetics, Hebrew University-Hadassah Medical Center, Jerusalem, Israel5Department of Metabolic Diseases, Hebrew University-Hadassah Medical Center, Jerusalem, Israel
| | - Samuel N Heyman
- Department of Internal Medicine, Hebrew University-Hadassah Medical Center, Jerusalem, Israel
| | - Aya Gal
- Center for Human Neurogenetics, Department of Neurology and Agnes Ginges, Hebrew University-Hadassah Medical Center, Jerusalem, Israel
| | - J P Newman
- Center for Human Neurogenetics, Department of Neurology and Agnes Ginges, Hebrew University-Hadassah Medical Center, Jerusalem, Israel
| | | | - Oded Abramsky
- Center for Human Neurogenetics, Department of Neurology and Agnes Ginges, Hebrew University-Hadassah Medical Center, Jerusalem, Israel
| | - Yoav Kohn
- Hebrew University-Hadassah School of Medicine, Jerusalem, Israel12Department of Child and Adolescent Psychiatry, Jerusalem Mental Health Center, Eitanim Psychiatric Hospital, Jerusalem, Israel
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Fischer S, Huemer M, Baumgartner M, Deodato F, Ballhausen D, Boneh A, Burlina AB, Cerone R, Garcia P, Gökçay G, Grünewald S, Häberle J, Jaeken J, Ketteridge D, Lindner M, Mandel H, Martinelli D, Martins EG, Schwab KO, Gruenert SC, Schwahn BC, Sztriha L, Tomaske M, Trefz F, Vilarinho L, Rosenblatt DS, Fowler B, Dionisi-Vici C. Clinical presentation and outcome in a series of 88 patients with the cblC defect. J Inherit Metab Dis 2014; 37:831-40. [PMID: 24599607 DOI: 10.1007/s10545-014-9687-6] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 01/27/2014] [Accepted: 01/30/2014] [Indexed: 12/17/2022]
Abstract
UNLABELLED The cblC defect is the most common inborn error of vitamin B12 metabolism. Despite therapeutic measures, the long-term outcome is often unsatisfactory. This retrospective multicentre study evaluates clinical, biochemical and genetic findings in 88 cblC patients. The questionnaire designed for the study evaluates clinical and biochemical features at both initial presentation and during follow up. Also the development of severity scores allows investigation of individual disease load, statistical evaluation of parameters between the different age of presentation groups, as well as a search for correlations between clinical endpoints and potential modifying factors. RESULTS No major differences were found between neonatal and early onset patients so that these groups were combined as an infantile-onset group representing 88 % of all cases. Hypotonia, lethargy, feeding problems and developmental delay were predominant in this group, while late-onset patients frequently presented with psychiatric/behaviour problems and myelopathy. Plasma total homocysteine was higher and methionine lower in infantile-onset patients. Plasma methionine levels correlated with "overall impression" as judged by treating physicians. Physician's impression of patient's well-being correlated with assessed disease load. We confirmed the association between homozygosity for the c.271dupA mutation and infantile-onset but not between homozygosity for c.394C>T and late-onset. Patients were treated with parenteral hydroxocobalamin, betaine, folate/folinic acid and carnitine resulting in improvement of biochemical abnormalities, non-neurological signs and mortality. However the long-term neurological and ophthalmological outcome is not significantly influenced. In summary the survey points to the need for prospective studies in a large cohort using agreed treatment modalities and monitoring criteria.
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Affiliation(s)
- Sabine Fischer
- University Children's Hospital Basel, Spitalstrasse 33, Basel, 4506, Switzerland
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Atkinson C, Miousse IR, Watkins D, Rosenblatt DS, Raiman JAJ. Clinical, Biochemical, and Molecular Presentation in a Patient with the cblD-Homocystinuria Inborn Error of Cobalamin Metabolism. JIMD Rep 2014; 17:77-81. [PMID: 25155779 PMCID: PMC4241196 DOI: 10.1007/8904_2014_340] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 07/04/2014] [Accepted: 07/10/2014] [Indexed: 01/24/2023] Open
Abstract
Disorders of intracellular cobalamin (vitamin B12) metabolism result from deficient synthesis of the coenzymes derived from vitamin B12: adenosylcobalamin and methylcobalamin. Disturbances of cobalamin-cofactor synthesis result in elevated levels of homocysteine and/or methylmalonic acid. Nine defects of intracellular cobalamin metabolism have been defined. The most common of these disorders is cblC (combined methylmalonic aciduria and homocystinuria). The cblD disorder is rare with fewer than twenty cases reported in the literature. Some cblD patients have combined methylmalonic aciduria and homocystinuria (referred to as "cblD original," "cblD-combined," or herein "cblD-MMA/HC"); some have isolated homocystinuria (referred to as "cblD-variant 1" or herein "cblD-HC"); and others have isolated methylmalonic aciduria (called "cblD-variant 2" or herein "cblD-MMA"). Only six cases of cblD-HC have been defined thus far. We report the 7th case of cblD-HC. The clinical manifestations, biochemical profile, genetic mutation, and plausible ancestry are discussed.
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Affiliation(s)
- Celia Atkinson
- />Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON Canada
- />Department of Paediatrics, Toronto East General Hospital, University of Toronto, Toronto, ON Canada
| | - Isabelle R. Miousse
- />Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, AR USA
| | - David Watkins
- />Division of Human Genetics, McGill University, Montreal, QC Canada
| | | | - Julian A. J. Raiman
- />Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, University of Toronto, Toronto, ON Canada
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D'Aco KE, Bearden D, Watkins D, Hyland K, Rosenblatt DS, Ficicioglu C. Severe 5,10-methylenetetrahydrofolate reductase deficiency and two MTHFR variants in an adolescent with progressive myoclonic epilepsy. Pediatr Neurol 2014; 51:266-70. [PMID: 25079578 DOI: 10.1016/j.pediatrneurol.2014.04.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 04/04/2014] [Accepted: 04/05/2014] [Indexed: 01/29/2023]
Abstract
BACKGROUND 5,10-Methylenetetrahydrofolate reductase (MTHFR) deficiency is an inborn error of the folate-recycling pathway that affects the remethylation of homocysteine to methionine. The clinical presentation of MTHFR deficiency is highly variable ranging from early neurological deterioration and death in infancy to a mild thrombophilia in adults. PATIENT AND METHODS We describe an adolescent girl with a history of mild learning disabilities who presented at age 14 years with an epilepsy syndrome initially thought to be juvenile myoclonic epilepsy. She later developed intractable epilepsy with myoclonus, leg weakness, cognitive decline, and ataxia consistent with the syndrome of progressive myoclonic epilepsy. This prompted further evaluation that revealed elevated plasma homocysteine and decreased plasma methionine. The diagnosis of MTHFR deficiency was confirmed based on extremely reduced fibroblast MTHFR activity (0.3 nmol CHO/mg prot/hr) as well as mutation analysis that revealed two variants in the MTHFR gene, a splice site mutation p (IVS5-1G>A), as well as a missense mutation (c.155 G>A; p. Arg52Gln). Therapy with folinic acid, betaine, and methionine has produced significant clinical improvement, including improved strength, less severe ataxia, and decreased seizure frequency, as well as improvements in her electroencephalography and electromyography. CONCLUSION This patient demonstrates the importance of considering MTHFR deficiency in the differential diagnosis of progressive myoclonic epilepsy because it is one of the few causes for which specific treatment is available.
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Affiliation(s)
- Kristin E D'Aco
- Department of Pediatrics, Division of Metabolism, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - David Bearden
- Department of Pedatrics, Division of Neurology, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - David Watkins
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | | | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Can Ficicioglu
- Department of Pediatrics, Division of Metabolism, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
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44
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Moreno-Garcia MA, Pupavac M, Rosenblatt DS, Tremblay ML, Jerome-Majewska LA. The Mmachc gene is required for pre-implantation embryogenesis in the mouse. Mol Genet Metab 2014; 112:198-204. [PMID: 24889031 DOI: 10.1016/j.ymgme.2014.05.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 05/06/2014] [Accepted: 05/06/2014] [Indexed: 02/06/2023]
Abstract
Patients with mutations in MMACHC have the autosomal recessive disease of cobalamin metabolism known as cblC. These patients are unable to convert cobalamin into the two active forms, methylcobalamin and adenosylcobalamin and consequently have elevated homocysteine and methylmalonic acid in blood and urine. In addition, some cblC patients have structural abnormalities, including congenital heart defects. MMACHC is conserved in the mouse and shows tissue and stage-specific expression pattern in midgestation stage embryos. To create a mouse model of cblC we generated a line of mice with a gene-trap insertion in intron 1 of the Mmachc gene, (Mmachc(Gt(AZ0348)Wtsi)). Heterozygous mice show a 50% reduction of MMACHC protein, and have significantly higher levels of homocysteine and methylmalonic acid in their blood. The Mmachc(Gt) allele was inherited with a transmission ratio distortion in matings with heterozygous animals. Furthermore, homozygous Mmachc(Gt) embryos were not found after embryonic day 3.5 and these embryos were unable to generate giant cells in outgrowth assays. Our findings confirm that cblC is modeled in mice with reduced levels of Mmachc and suggest an early requirement for Mmachc in mouse development.
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Affiliation(s)
- Maira A Moreno-Garcia
- Department of Human Genetics, McGill University, 1205 Avenue Docteur Penfield, N5/13, Montreal, Quebec H3A 1B1, Canada
| | - Mihaela Pupavac
- Department of Human Genetics, McGill University, 1205 Avenue Docteur Penfield, N5/13, Montreal, Quebec H3A 1B1, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, 1205 Avenue Docteur Penfield, N5/13, Montreal, Quebec H3A 1B1, Canada; Department of Pediatrics, McGill University, Research Institute, Place Toulon, 4060 Ste. Catherine West PT 420, Montreal Children's Hospital, Montreal, Quebec H3Z 2Z3, Canada
| | - Michel L Tremblay
- Department of Biochemistry, McGill University, Goodman Cancer Research Center, 1160 Avenue Pine, Montreal, Quebec, Canada
| | - Loydie A Jerome-Majewska
- Department of Human Genetics, McGill University, 1205 Avenue Docteur Penfield, N5/13, Montreal, Quebec H3A 1B1, Canada; Department of Pediatrics, McGill University, Research Institute, Place Toulon, 4060 Ste. Catherine West PT 420, Montreal Children's Hospital, Montreal, Quebec H3Z 2Z3, Canada; Department of Anatomy and Cell Biology, McGill University, Strathcona Anatomy and Dentistry Building, 3640 University Street, Montreal, Quebec H3A2B2, Canada.
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45
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Trakadis YJ, Alfares A, Bodamer OA, Buyukavci M, Christodoulou J, Connor P, Glamuzina E, Gonzalez-Fernandez F, Bibi H, Echenne B, Manoli I, Mitchell J, Nordwall M, Prasad C, Scaglia F, Schiff M, Schrewe B, Touati G, Tchan MC, Varet B, Venditti CP, Zafeiriou D, Rupar CA, Rosenblatt DS, Watkins D, Braverman N. Update on transcobalamin deficiency: clinical presentation, treatment and outcome. J Inherit Metab Dis 2014; 37:461-73. [PMID: 24305960 DOI: 10.1007/s10545-013-9664-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 11/13/2013] [Accepted: 11/14/2013] [Indexed: 10/25/2022]
Abstract
Transcobalamin (TC) transports cobalamin from blood into cells. TC deficiency is a rare autosomal recessive disorder usually presenting in early infancy with failure to thrive, weakness, diarrhoea, pallor, anemia, and pancytopenia or agammaglobulinemia. It can sometimes resemble neonatal leukemia or severe combined immunodeficiency disease. Diagnosis of TC deficiency is suspected based on megaloblastic anemia, elevation of total plasma homocysteine, and blood or urine methylmalonic acid. It is confirmed by studying the synthesis of TC in cultured fibroblasts, or by molecular analysis of the TCN2 gene. TC deficiency is treatable with supplemental cobalamin, but the optimal type, route and frequency of cobalamin administration and long term patient outcomes are unknown. Here we present a series of 30 patients with TC deficiency, including an update on multiple previously published patients, in order to evaluate the different treatment strategies and provide information about long term outcome. Based on the data presented, current practice appears to favour treatment of individuals with TC deficiency by intramuscular injections of hydroxy- or cyanocobalamin. In most cases presented, at least weekly injections (1 mg IM) were necessary to ensure optimal treatment. Most centres adjusted the treatment regimen based on monitoring CBC, total plasma homocysteine, plasma and urine methylmalonic acid, as well as, clinical status. Finally, continuing IM treatment into adulthood appears to be beneficial.
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Affiliation(s)
- Y J Trakadis
- Department of Medical Genetics, McGill University Health Centre, Montreal, QC, Canada,
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Moreno-Garcia MA, Rosenblatt DS, Jerome-Majewska LA. Vitamin B(12) metabolism during pregnancy and in embryonic mouse models. Nutrients 2013; 5:3531-50. [PMID: 24025485 PMCID: PMC3798919 DOI: 10.3390/nu5093531] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 08/10/2013] [Accepted: 08/23/2013] [Indexed: 11/16/2022] Open
Abstract
Vitamin B(12) (cobalamin, Cbl) is required for cellular metabolism. It is an essential coenzyme in mammals for two reactions: the conversion of homocysteine to methionine by the enzyme methionine synthase and the conversion of methylmalonyl-CoA to succinyl-CoA by the enzyme methylmalonyl-CoA mutase. Symptoms of Cbl deficiency are hematological, neurological and cognitive, including megaloblastic anaemia, tingling and numbness of the extremities, gait abnormalities, visual disturbances, memory loss and dementia. During pregnancy Cbl is essential, presumably because of its role in DNA synthesis and methionine synthesis; however, there are conflicting studies regarding an association between early pregnancy loss and Cbl deficiency. We here review the literature about the requirement for Cbl during pregnancy, and summarized what is known of the expression pattern and function of genes required for Cbl metabolism in embryonic mouse models.
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Affiliation(s)
- Maira A. Moreno-Garcia
- Department of Human Genetics, McGill University, 1205 Avenue Docteur Penfield, N5/13,Montreal, Quebec, Canada H3A 1B1; E-Mails: (M.A.M.-G.); (D.S.R.)
| | - David S. Rosenblatt
- Department of Human Genetics, McGill University, 1205 Avenue Docteur Penfield, N5/13,Montreal, Quebec, Canada H3A 1B1; E-Mails: (M.A.M.-G.); (D.S.R.)
- Department of Pediatrics, McGill University, Montreal, Quebec, Canada H3H 1P3
| | - Loydie A. Jerome-Majewska
- Department of Human Genetics, McGill University, 1205 Avenue Docteur Penfield, N5/13,Montreal, Quebec, Canada H3A 1B1; E-Mails: (M.A.M.-G.); (D.S.R.)
- Department of Pediatrics, McGill University, Montreal, Quebec, Canada H3H 1P3
- McGill University Health Centre, 4060 Ste. Catherine West, PT 420, Montreal, Quebec, Canada H3Z 2Z3
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-514-412-4400 (ext. 23279); Fax: +1-514-412-4331
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47
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Yu HC, Sloan JL, Scharer G, Brebner A, Quintana AM, Achilly NP, Manoli I, Coughlin CR, Geiger EA, Schneck U, Watkins D, Suormala T, Van Hove JLK, Fowler B, Baumgartner MR, Rosenblatt DS, Venditti CP, Shaikh TH. An X-linked cobalamin disorder caused by mutations in transcriptional coregulator HCFC1. Am J Hum Genet 2013; 93:506-14. [PMID: 24011988 DOI: 10.1016/j.ajhg.2013.07.022] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 07/09/2013] [Accepted: 07/26/2013] [Indexed: 12/31/2022] Open
Abstract
Derivatives of vitamin B12 (cobalamin) are essential cofactors for enzymes required in intermediary metabolism. Defects in cobalamin metabolism lead to disorders characterized by the accumulation of methylmalonic acid and/or homocysteine in blood and urine. The most common inborn error of cobalamin metabolism, combined methylmalonic acidemia and hyperhomocysteinemia, cblC type, is caused by mutations in MMACHC. However, several individuals with presumed cblC based on cellular and biochemical analysis do not have mutations in MMACHC. We used exome sequencing to identify the genetic basis of an X-linked form of combined methylmalonic acidemia and hyperhomocysteinemia, designated cblX. A missense mutation in a global transcriptional coregulator, HCFC1, was identified in the index case. Additional male subjects were ascertained through two international diagnostic laboratories, and 13/17 had one of five distinct missense mutations affecting three highly conserved amino acids within the HCFC1 kelch domain. A common phenotype of severe neurological symptoms including intractable epilepsy and profound neurocognitive impairment, along with variable biochemical manifestations, was observed in all affected subjects compared to individuals with early-onset cblC. The severe reduction in MMACHC mRNA and protein within subject fibroblast lines suggested a role for HCFC1 in transcriptional regulation of MMACHC, which was further supported by the identification of consensus HCFC1 binding sites in MMACHC. Furthermore, siRNA-mediated knockdown of HCFC1 expression resulted in the coordinate downregulation of MMACHC mRNA. This X-linked disorder demonstrates a distinct disease mechanism by which transcriptional dysregulation leads to an inborn error of metabolism with a complex clinical phenotype.
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Affiliation(s)
- Hung-Chun Yu
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
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48
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Affiliation(s)
- David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal General Hospital, 1650 Cedar Avenue, Room L3-319, Montreal, Quebec, Canada.
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49
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Illson ML, Dempsey-Nunez L, Kent J, Huang Q, Brebner A, Raff ML, Watkins D, Gilfix BM, Wittwer CT, Rosenblatt DS. High resolution melting analysis of the MMAB gene in cblB patients and in those with undiagnosed methylmalonic aciduria. Mol Genet Metab 2013; 110:86-9. [PMID: 23707710 DOI: 10.1016/j.ymgme.2013.04.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Accepted: 04/29/2013] [Indexed: 11/24/2022]
Abstract
Isolated methylmalonic aciduria (MMA) results either from a defect in the mitochondrial enzyme methylmalonylCoA mutase (MCM), or in the intracellular conversion of vitamin B12 (cobalamin) into its active coenzyme adenosylcobalamin (AdoCbl). Mutations in the MMAB gene affect the function of the enzyme ATP:cob(I)alamin adenosyltransferase (ATR) and the production of AdoCbl. Measurement of MCM function in cultured patient fibroblasts, followed by somatic cell complementation analysis in cases where MCM function is decreased, has classically been used to diagnose the cblB cobalamin disorder. A patient with persistent MMA, who could not be diagnosed using traditional somatic cell studies, was subsequently shown by sequencing in a clinical laboratory to contain two variants in the MMAB gene. This observation brings into question whether somatic cell studies have failed to diagnose other cblB patients with mild cellular phenotypes. A high resolution melting analysis (HRMA) assay was developed for the MMAB gene. It was used to scan 96 reference samples and two cohorts of patients: 42 patients diagnosed with cblB by complementation studies; and 181 patients with undiagnosed MMA. MMAB mutations, including one novel nonsense mutation (c.12 C>A [p.C4X]), were identified in all members of the cblB cohort. Four patients with undiagnosed MMA, including the index case described above, were found to contain variants in the MMAB gene: c.185C>T (p.T62M), c.394T>C (p.C132R), c.398C>T (p.S133F), c.521C>T (p.S174L), c.572G>A (p.R191Q). Only the index case was found to have two variants, suggesting that somatic cell studies diagnose almost all cblB patients.
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Affiliation(s)
- Margaret L Illson
- Department of Human Genetics, McGill University, Montreal, QC, Canada
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Rosenblatt DS. Victor McKusick and the History of Medical Genetics. J Med Genet 2013. [DOI: 10.1136/jmedgenet-2013-101936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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