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Turgut GT, Güleç Ç, Sarac Sivrikoz T, Kale H, Karaman B, Nishimura G, Altunoglu U. Antenatal diagnostic dilemma in a pseudodominant pedigree with lamin-B receptor (LBR)-related regressive spondylometaphyseal dysplasia. Am J Med Genet A 2021; 188:253-258. [PMID: 34467646 DOI: 10.1002/ajmg.a.62479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 08/11/2021] [Accepted: 08/15/2021] [Indexed: 11/07/2022]
Abstract
The lamin-B receptor (LBR) encodes a dual-functioning inner nuclear membrane protein essential for cholesterol biosynthesis and chromatin organization. LBR pathogenic variants cause distinct phenotypes due to the dual function of LBR, including Pelger-Huët anomaly (PHA), PHA with mild skeletal anomalies (PHASK; MIM# 618019), LBR-related regressive type of spondylometaphyseal dysplasia (LBR-R-SMD), Greenberg dysplasia (MIM# 215140). We here report the first case with radiological manifestations of LBR-R-SMD in the fetal period, and milder skeletal findings in the similarly affected father. Direct sequencing of LBR revealed homozygous c.1534C>T (p.Arg512Trp) in exon 12 in both affected individuals. Our report further refines the early phenotype in LBR-R-SMD, and demonstrates that the p.Arg512Trp mutation is associated with PHA. We propose that LBR-R-SMD should be considered as a differential diagnosis in pregnancies with sonographic evidence of short and bowed tubular bones with narrow thorax. Evaluating peripheral blood smears of expectant parents for the presence of PHA may lead to a clinical diagnosis, allowing for comprehensive prenatal genetic counseling.
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Affiliation(s)
- Gozde Tutku Turgut
- Department of Medical Genetics, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Çağrı Güleç
- Department of Medical Genetics, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Tugba Sarac Sivrikoz
- Department of Obstetrics and Gynecology, Division of Perinatology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Hamdi Kale
- Department of Medical Genetics, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Birsen Karaman
- Department of Medical Genetics, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey.,Department of Pediatric Basic Sciences, Institute of Child Health, Istanbul University, Istanbul, Turkey
| | - Gen Nishimura
- Center for Intractable Diseases, Saitama Medical University Hospital, Saitama, Japan
| | - Umut Altunoglu
- Department of Medical Genetics, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey.,Department of Medical Genetics, Koc University School of Medicine (KUSOM), Istanbul, Turkey
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Hall CM, Liu B, Haworth A, Reed L, Pryce J, Mansour S. Early prenatal presentation of the cartilage-hair hypoplasia / anauxetic dysplasia spectrum of disorders mimicking recurrent thanatophoric dysplasia. Eur J Med Genet 2021; 64:104162. [PMID: 33567347 DOI: 10.1016/j.ejmg.2021.104162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 01/04/2021] [Accepted: 02/04/2021] [Indexed: 11/24/2022]
Abstract
Three sibling fetuses identified with limb shortening and thoracic narrowing at twelve weeks' gestation on first trimester ultrasound examination are presented. The parents were non-consanguineous, Caucasian, healthy, of normal stature and had a healthy normal daughter. The radiographic abnormalities were highly suggestive of thanatophoric dysplasia, but molecular analysis failed to identify a pathogenic variant in FGFR3. The three fetuses were found to have identical compound heterozygous mutations in RMRP in trans, one inherited from the mother and one from the father. This represents the early prenatal presentation and fetal findings of metaphyseal dysplasia type McKusick (Cartilage-hair hypoplasia; CHH)/anauxetic dysplasia spectrum of disorders.
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Affiliation(s)
- Christine M Hall
- St George's, University of London, UK; Emeritus, Department of Radiology, Great Ormond Street Hospital, London, UK
| | - Becky Liu
- Fetal Medicine Unit, St George's University Hospitals NHS Foundation Trust, London, UK
| | - Andrea Haworth
- Congenica Limited, Biodata Innovation Centre, Wellcome Genome Campus, Cambridge, UK
| | - Laura Reed
- Congenica Limited, Biodata Innovation Centre, Wellcome Genome Campus, Cambridge, UK
| | - Jeremy Pryce
- Department of Pathology, St George's University Hospitals NHS Foundation Trust, UK
| | - Sahar Mansour
- St George's, University of London, UK; SW Thames Regional Genetics Service, St George's University Hospitals NHS Foundation Trust, UK.
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Lugli L, Ciancia S, Bertucci E, Lucaccioni L, Calabrese O, Madeo S, Berardi A, Iughetti L. Homozygous n.64C>T mutation in mitochondrial RNA-processing endoribonuclease gene causes cartilage hair hypoplasia syndrome in two siblings. Eur J Med Genet 2021; 64:104136. [PMID: 33444820 DOI: 10.1016/j.ejmg.2021.104136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 09/07/2020] [Accepted: 01/03/2021] [Indexed: 10/22/2022]
Abstract
Cartilage hair hypoplasia syndrome (OMIM # 250250) is a rare autosomal recessive metaphyseal dysplasia, characterized by disproportionate short stature, hair hypoplasia and variable extra-skeletal manifestations, including immunodeficiency, anemia, intestinal diseases and predisposition to cancers. Cartilage hair hypoplasia syndrome has a broad phenotype and it is caused by homozygous or compound heterozygous mutation in the mitochondrial RNA-processing endoribonuclease on chromosome 9p13. Although it is well known as a primordial dwarfism, descriptions of the prenatal growth are missing. To add further details to the knowledge of the phenotypic spectrum of the disease, we report on two siblings with cartilage hair hypoplasia syndrome, presenting n.64C > T homozygous mutation in the mitochondrial RNA-processing endoribonuclease gene. We describe the prenatal and postnatal growth pattern of the two affected patients, showing severe pre- and post-natal growth deficiency.
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Affiliation(s)
- Licia Lugli
- Neonatology Unit, Mother-Child Department, University Hospital of Modena, Italy.
| | - Silvia Ciancia
- Post-graduated School of Pediatrics, Department of Medical and Surgical Sciences for Mother, Children and Adults, University of Modena and Reggio Emilia, Italy
| | - Emma Bertucci
- Obstetric-Gynecology Unit, Mother-Child Department, University Hospital of Modena, Italy
| | - Laura Lucaccioni
- Neonatology Unit, Mother-Child Department, University Hospital of Modena, Italy
| | - Olga Calabrese
- Genetic Unit, Mother-Child Department, University Hospital of Modena, Italy
| | - Simona Madeo
- Post-graduated School of Pediatrics, Department of Medical and Surgical Sciences for Mother, Children and Adults, University of Modena and Reggio Emilia, Italy
| | - Alberto Berardi
- Neonatology Unit, Mother-Child Department, University Hospital of Modena, Italy
| | - Lorenzo Iughetti
- Post-graduated School of Pediatrics, Department of Medical and Surgical Sciences for Mother, Children and Adults, University of Modena and Reggio Emilia, Italy
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Sun X, Zhang R, Liu M, Chen H, Chen L, Luo F, Zhang D, Huang J, Li F, Ni Z, Qi H, Su N, Jin M, Yang J, Tan Q, Du X, Chen B, Huang H, Chen S, Yin L, Xu X, Deng C, Luo L, Xie Y, Chen L. Rmrp Mutation Disrupts Chondrogenesis and Bone Ossification in Zebrafish Model of Cartilage-Hair Hypoplasia via Enhanced Wnt/β-Catenin Signaling. J Bone Miner Res 2019; 34:2101-2116. [PMID: 31237961 DOI: 10.1002/jbmr.3820] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 06/11/2019] [Accepted: 06/14/2019] [Indexed: 01/09/2023]
Abstract
Cartilage-hair hypoplasia (CHH) is an autosomal recessive metaphyseal chondrodysplasia characterized by bone dysplasia and many other highly variable features. The gene responsible for CHH is the RNA component of the mitochondrial RNA-processing endoribonuclease (RMRP) gene. Currently, the pathogenesis of osteochondrodysplasia and extraskeletal manifestations in CHH patients remains incompletely understood; in addition, there are no viable animal models for CHH. We generated an rmrp KO zebrafish model to study the developmental mechanisms of CHH. We found that rmrp is required for the patterning and shaping of pharyngeal arches. Rmrp mutation inhibits the intramembranous ossification of skull bones and promotes vertebrae ossification. The abnormalities of endochondral bone ossification are variable, depending on the degree of dysregulated chondrogenesis. Moreover, rmrp mutation inhibits cell proliferation and promotes apoptosis through dysregulating the expressions of cell-cycle- and apoptosis-related genes. We also demonstrate that rmrp mutation upregulates canonical Wnt/β-catenin signaling; the pharmacological inhibition of Wnt/β-catenin could partially alleviate the chondrodysplasia and increased vertebrae mineralization in rmrp mutants. Our study, by establishing a novel zebrafish model for CHH, partially reveals the underlying mechanism of CHH, hence deepening our understanding of the role of rmrp in skeleton development.
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Affiliation(s)
- Xianding Sun
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Ruobin Zhang
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Mi Liu
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Hangang Chen
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Liang Chen
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Fengtao Luo
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Dali Zhang
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Junlan Huang
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Fangfang Li
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Zhenhong Ni
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Huabing Qi
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Nan Su
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Min Jin
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Jing Yang
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Qiaoyan Tan
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Xiaolan Du
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Bo Chen
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Haiyang Huang
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Shuai Chen
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Liangjun Yin
- Department of Orthopedic Surgery, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, 400010, China
| | - Xiaoling Xu
- Faculty of Health Sciences, University of Macau, Macau SAR, China
| | - Chuxia Deng
- Faculty of Health Sciences, University of Macau, Macau SAR, China
| | - Lingfei Luo
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, Laboratory of Molecular Developmental Biology, School of Life Sciences, Southwest University, Beibei, Chongqing, 400715, China
| | - Yangli Xie
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
| | - Lin Chen
- Laboratory of Wound Repair and Rehabilitation, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, 400042, China
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Criteria for radiologic diagnosis of hypochondroplasia in neonates. Pediatr Radiol 2016; 46:513-8. [PMID: 26867606 DOI: 10.1007/s00247-015-3518-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 10/20/2015] [Accepted: 11/19/2015] [Indexed: 10/22/2022]
Abstract
BACKGROUND A radiologic diagnosis of hypochondroplasia is hampered by the absence of age-dependent radiologic criteria, particularly in the neonatal period. OBJECTIVE To establish radiologic criteria and scoring system for identifying neonates with fibroblast growth factor receptor 3 (FGFR3)-associated hypochondroplasia. MATERIALS AND METHODS This retrospective study included 7 hypochondroplastic neonates and 30 controls. All subjects underwent radiologic examination within 28 days after birth. We evaluated parameters reflecting the presence of (1) short ilia, (2) squared ilia, (3) short greater sciatic notch, (4) horizontal acetabula, (5) short femora, (6) broad femora, (7) metaphyseal flaring, (8) lumbosacral interpedicular distance narrowing and (9) ovoid radiolucency of the proximal femora. RESULTS Only parameters 1, 3, 4, 5 and 6 were statistically different between the two groups. Parameters 3, 5 and 6 did not overlap between the groups, while parameters 1 and 4 did. Based on these results, we propose a scoring system for hypochondroplasia. Two major criteria (parameters 3 and 6) were assigned scores of 2, whereas 4 minor criteria (parameters 1, 4, 5 and 9) were assigned scores of 1. All neonates with hypochondroplasia in our material scored ≥6. CONCLUSION Our set of diagnostic radiologic criteria might be useful for early identification of hypochondroplastic neonates.
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Armistead J, Patel N, Wu X, Hemming R, Chowdhury B, Basra GS, Del Bigio MR, Ding H, Triggs-Raine B. Growth arrest in the ribosomopathy, Bowen-Conradi syndrome, is due to dramatically reduced cell proliferation and a defect in mitotic progression. Biochim Biophys Acta Mol Basis Dis 2015; 1852:1029-37. [PMID: 25708872 DOI: 10.1016/j.bbadis.2015.02.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 02/10/2015] [Accepted: 02/14/2015] [Indexed: 02/05/2023]
Abstract
Bowen-Conradi syndrome (BCS) is a ribosomopathy characterized by severe developmental delay and growth failure that typically leads to death by one year of age. It is caused by a c.257A>G, p.D86G substitution in the ribosomal biogenesis protein, Essential for Mitotic Growth 1 (EMG1). We generated a knock-in of the D86G substitution in mice to characterize the effects of EMG1 deficiency, particularly in the brain, where EMG1 expression is high. Embryos homozygous for the mutation in Emg1 were small for gestational age with neural tube defects, and died between embryonic days 8.5 and 12.5. These embryos exhibited dramatically reduced cell proliferation, which we also detected in autopsy brain tissue and bone marrow of BCS patients, consistent with a requirement for high levels of EMG1 in tissues with rapid cell proliferation. In fibroblasts derived from the BCS mouse embryos, we detected a high proportion of binucleated cells, indicating that a mitotic defect underlies the growth arrest in BCS. These studies add to growing evidence of a link between ribosome biogenesis, mitotic progression, and brain development that is currently unexplored.
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Affiliation(s)
- Joy Armistead
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada; Manitoba Institute of Child Health, Winnipeg, MB, Canada; Institute of Developmental Biology, University of Cologne, Cologne, Germany.
| | - Nehal Patel
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada.
| | - Xiaoli Wu
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada.
| | - Richard Hemming
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada.
| | - Biswajit Chowdhury
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada; Manitoba Institute of Child Health, Winnipeg, MB, Canada.
| | - Gagandeep Singh Basra
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada.
| | - Marc R Del Bigio
- Department of Pathology, University of Manitoba, Winnipeg, MB, Canada; Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, MB, Canada; Manitoba Institute of Child Health, Winnipeg, MB, Canada.
| | - Hao Ding
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada.
| | - Barbara Triggs-Raine
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada; Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, MB, Canada; Manitoba Institute of Child Health, Winnipeg, MB, Canada.
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Variable phenotype of severe immunodeficiencies associated with RMRP gene mutations. J Clin Immunol 2015; 35:147-57. [PMID: 25663137 DOI: 10.1007/s10875-015-0135-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 01/23/2015] [Indexed: 10/24/2022]
Abstract
PURPOSE Mutations in RMRP primarily give rise to Cartilage Hair Hypoplasia (CHH), a highly diverse skeletal disorder which can be associated with severe immunodeficiency. Increased availability of RMRP mutation screening has uncovered a number of infants with significant immunodeficiency but only mild or absent skeletal features. We surveyed the clinical and immunological phenotype of children who have undergone allogeneic haematopoietic stem cell transplantation for this condition in the UK. METHODS Thirteen patients with confirmed RMRP mutations underwent allogeneic stem cell transplantation (SCT) at two nationally commissioned centres using a variety of donors and conditioning regimens. Records were retrospectively reviewed. RESULTS Median time from clinical presentation to diagnosis was 12 months (range 1 to 276 months), with three infants diagnosed with severe combined immunodeficiency (SCID) without radiographical manifestations of CHH. A total of 17 allogeneic procedures were performed on 13 patients including two stem-cell top-ups. The median age at transplant was 32.4 months (range 1.5 to 125 months). Of the eleven surviving patients, median follow-up was 50 months (range 21.6 to 168 months). CONCLUSIONS RMRP mutations can cause short stature and significant immunodeficiency which can be corrected by allogeneic SCT and the diagnosis should be considered even in the absence of skeletal manifestations.
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Kwan A, Manning M, Zollars LK, Hoyme HE. Marked variability in the radiographic features of cartilage-hair hypoplasia: Case report and review of the literature. Am J Med Genet A 2012; 158A:2911-6. [DOI: 10.1002/ajmg.a.35604] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Accepted: 07/07/2012] [Indexed: 11/07/2022]
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Thiel CT, Rauch A. The molecular basis of the cartilage-hair hypoplasia-anauxetic dysplasia spectrum. Best Pract Res Clin Endocrinol Metab 2011; 25:131-42. [PMID: 21396580 DOI: 10.1016/j.beem.2010.08.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Cartilage-hair hypoplasia and anauxetic dysplasia are two autosomal recessive skeletal dysplasias characterized by different degrees from metaphyseal to spondylo-meta-epiphyseal dysplasia and variable additional features including predisposition to cancer, anemia, immunodeficiency, and gastrointestinal malabsorption and Hirschsprung's disease. Both are caused by mutations in the untranslated RMRP gene, which forms the RNA subunit of the RNase MRP complex. This complex is involved in the ribosome assembly by cleavage of 5.8S rRNA, cell cycle control by Cyclin B2 mRNA cleavage at the end of mitosis, processing the mitochondrial RNA, and forming a complex with hTERT suggesting a possible involvement in expression regulation by siRNA synthesis. The degree of skeletal dysplasia correlates mainly with the rRNA cleavage activity, whereas significantly diminished mRNA cleavage activity is a prerequisite for immunodeficiency. Thus, the clinical phenotype emerges in most cases of the combined effect on the respective effect on RNase MRP function.
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Affiliation(s)
- Christian T Thiel
- Institute of Human Genetics, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg, Schwabachanlage 10, Erlangen, Germany.
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Le Merrer M, Cormier Daire V, Maroteaux P. Re-evaluation of kyphomelic dysplasia. Am J Med Genet A 2003; 120A:289-91. [PMID: 12833417 DOI: 10.1002/ajmg.a.20035] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Bonafé L, Schmitt K, Eich G, Giedion A, Superti-Furga A. RMRP gene sequence analysis confirms a cartilage-hair hypoplasia variant with only skeletal manifestations and reveals a high density of single-nucleotide polymorphisms. Clin Genet 2002; 61:146-51. [PMID: 11940090 DOI: 10.1034/j.1399-0004.2002.610210.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Mutations in the RMRP gene that codes for an RNA subunit of the MRP RNAse complex are the cause of cartilage-hair hypoplasia (CHH; MIM 250250). We tested the hypothesis that recessive metaphyseal dysplasia without hypotrichosis (M1M 250460), a disorder presenting with short stature and metaphyseal dysplasia similar to CHH, but lacking hair anomalies, immunodeficiency and other extra skeletal features, might be allelic to CHH. We identified four mutation-carrying alleles segregating with the skeletal phenotype in two unrelated boys and their parents. One allele carried the common Finnish mutation +70A--> G; the remaining three carried +195C--> T, +238C--> T, and dupAAGCTGAGGACG at -2. Sequencing 120 alleles from a control group revealed an unusually high density of single-nucleotide polymorphisms in and around the RMRP gene: the biological significance of this finding is unclear. We conclude that recessive metaphyseal dysplasia without hypotrichosis is a variant of CHH, manifesting only as short stature and metaphyseal dysplasia. Precise diagnosis of this form of metaphyseal dysplasia is not without importance because of recessive inheritance with corresponding recurrence risk, as well as because of potential complications such as anaemia, susceptibility to infections and the increased likelihood of developing cancer. The short stature and metaphyseal changes associated with cone-shaped epiphyses of the hands should raise the diagnostic possibility of a CHH-related disorder that can then be confirmed by mutation analysis.
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Affiliation(s)
- L Bonafé
- Division of Metabolism and Molecular Paediatrics and Division of Radiology, University Children's Hospital, Zurich, Switzerland
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13
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Abstract
For patients with well-characterized, rapidly fatal, nonmalignant immunodeficiency disorders, such as SCID, the decision to proceed with allogeneic SCT is clear-cut. For patients with many other disorders, this decision can be extremely difficult. Disorders such as LAD or CGD have a variable natural history. Each patient must be considered individually, with the risk for SCT-related morbidity and mortality carefully weighed against that of the underlying disease. Significant advances during the past 10 years have made SCT a much safer procedure. Use of nonmyeloablative conditioning regimens as a means of reducing toxicity of high-dose chemotherapy and irradiation hold great promise. Highly immunosuppressive, nonchemotherapeutic agents that inhibit graft rejection or GVHD by blocking the critical costimulatory component of the T-cell receptor-antigen interaction are beginning to emerge and may be ideal for SCT of nonmalignant diseases. Therefore, the risk-benefit equation must be reassessed each year as the severity of patients' disorders is better defined and techniques of SCT improve.
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Affiliation(s)
- M E Horwitz
- Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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14
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Abstract
Cartilage hair hypoplasia (CHH), or metaphyseal dysplasia McKusick type, classically comprises short stature and scant fine hair. In this skeletal dysplasia there is a high incidence of immune deficiency and Hirschsprung disease, as well as a higher rate of malignancy. Clinical findings may be subtle in young children, and radiographic changes may be elusive. We present four children below age 2 in whom the clinical diagnosis of CHH was confirmed radiographically. We emphasize radiologically and clinically discernable anterior angulation of the entire sternum, a sign not previously described in this dysplasia.
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Affiliation(s)
- R B Glass
- Department of Diagnostic Imaging and Radiology, Children's National Medical Center and the George Washington University School of Medicine and Health Sciences, Washington, DC, USA.
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Berthet F, Siegrist CA, Ozsahin H, Tuchschmid P, Eich G, Superti-Furga A, Seger RA. Bone marrow transplantation in cartilage-hair hypoplasia: correction of the immunodeficiency but not of the chondrodysplasia. Eur J Pediatr 1996; 155:286-90. [PMID: 8777921 DOI: 10.1007/bf02002714] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
UNLABELLED We diagnosed cartilage-hair hypoplasia (CHH) in a female child with prenatal-onset short stature, metaphyseal chondrodysplasia, and severe combined immunodeficiency leading to recurrent, severe respiratory tract infections. The patient required several hospital admissions during her 1st year of life and failed to thrive in spite of antimicrobial therapy and hypercaloric nutrition. Bone marrow transplantation (BMT) from an HLA-identical sister was performed at age 16 months after conditioning with busulphan and cyclophosphamide, using 9 x 10(8) nucleated bone marrow cells/kg body weight. Graft-versus-host disease prophylaxis consisted of cyclosporine and methotrexate. The post-transplantation period was uneventful. She developed full and sustained chimerism as demonstrated by DNA analysis of granulocytes and mononucleated cells on days 44, 69 and 455 post BMT. Cellular immunity was completely reconstituted at 4 months, humoral immunity at 15 months post BMT. The patient is alive and well 24 months post BMT without medication, but the radiological osseous changes persist, and longitudinal growth remains markedly below the 10th percentile for CHH standards; her height at age 3 years 4 months is 66 cm. CONCLUSION In this patient with unusually severe CHH, bone-marrow transplantation has fully corrected the immune deficiency but has had no influence on the course of the chondrodysplasia.
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Affiliation(s)
- F Berthet
- Division of Immunology and Hematology, University Children's Hospital, Zurich, Switzerland
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Affiliation(s)
- A Giedion
- Kinderspital, Department of Radiology, Zürich, Switzerland
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