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Wang YC, Lan LC, Yang X, Xiao J, Liu HX, Shan QW. A case report of classic galactosemia with a GALT gene variant and a literature review. BMC Pediatr 2024; 24:352. [PMID: 38778342 PMCID: PMC11110268 DOI: 10.1186/s12887-024-04769-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 04/16/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND Galactosemia is an autosomal recessive disorder resulting from an enzyme defect in the galactose metabolic pathway. The most severe manifestation of classic galactosemia is caused by galactose-1-phosphate uridylyltransferase (GALT) deficiency, and this condition can be fatal during infancy if left untreated. It also may result in long-term complications in affected individuals. CASE PRESENTATION This report describes a patient whose initial clinical symptoms were jaundice and liver dysfunction. The patient's liver and coagulation functions did not improve after multiple admissions and treatment with antibiotics, hepatoprotective and choleretic agents and blood transfusion. Genetic analysis revealed the presence of two variants in the GALT gene in the compound heterozygous state: c.377 + 2dup and c.368G > C (p.Arg123Pro). Currently, the variant locus (c.377 + 2dup) in the GALT gene has not been reported in the Human Gene Mutation Database (HGMD), while c.368G > C (p.Arg123Pro) has not been reported in the Genome Aggregation Database (GnomAD) nor the HGMD in East Asian population. We postulated that the two variants may contribute to the development of classical galactosemia. CONCLUSIONS Applications of whole-exome sequencing to detect the two variants can improve the detection and early diagnosis of classical galactosemia and, more specifically, may identify individuals who are compound heterozygous with variants in the GALT gene. Variants in the GALT gene have a potential therapeutic significance for classical galactosemia.
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Affiliation(s)
- Yong-Cai Wang
- Difficult and Critical Illness Center, Pediatric Clinical Medical Research Center of Guangxi, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Nanning, 530021, Guangxi Zhuang Autonomous Region, China
- Dazhou Central Hosptial, No. 56 Nanyuemiao Street, Tongchuan District, Dazhou, 635000, Sichuan Province, China
| | - Lian-Cheng Lan
- Difficult and Critical Illness Center, Pediatric Clinical Medical Research Center of Guangxi, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Nanning, 530021, Guangxi Zhuang Autonomous Region, China
| | - Xia Yang
- Difficult and Critical Illness Center, Pediatric Clinical Medical Research Center of Guangxi, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Nanning, 530021, Guangxi Zhuang Autonomous Region, China
| | - Juan Xiao
- Difficult and Critical Illness Center, Pediatric Clinical Medical Research Center of Guangxi, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Nanning, 530021, Guangxi Zhuang Autonomous Region, China
| | - Hai-Xin Liu
- Difficult and Critical Illness Center, Pediatric Clinical Medical Research Center of Guangxi, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Nanning, 530021, Guangxi Zhuang Autonomous Region, China
| | - Qing-Wen Shan
- Difficult and Critical Illness Center, Pediatric Clinical Medical Research Center of Guangxi, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Nanning, 530021, Guangxi Zhuang Autonomous Region, China.
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Balakrishnan B, Yan X, McCue MD, Bellagamba O, Guo A, Winkler F, Thall J, Crawford L, Dimen R, Chen S, McEnaney S, Wu Y, Zimmer M, Sarkis J, Martini PG, Finn PF, Lai K. Whole-body galactose oxidation as a robust functional assay to assess the efficacy of gene-based therapies in a mouse model of Galactosemia. Mol Ther Methods Clin Dev 2024; 32:101191. [PMID: 38352271 PMCID: PMC10863324 DOI: 10.1016/j.omtm.2024.101191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 01/12/2024] [Indexed: 02/16/2024]
Abstract
Despite the implementation of lifesaving newborn screening programs and a galactose-restricted diet, many patients with classic galactosemia develop long-term debilitating neurological deficits and primary ovarian insufficiency. Previously, we showed that the administration of human GALT mRNA predominantly expressed in the GalT gene-trapped mouse liver augmented the expression of hepatic GALT activity, which decreased not only galactose-1 phosphate (gal-1P) in the liver but also peripheral tissues. Since each peripheral tissue requires distinct methods to examine the biomarker and/or GALT effect, this highlights the necessity for alternative strategies to evaluate the overall impact of therapies. In this study, we established that whole-body galactose oxidation (WBGO) as a robust, noninvasive, and specific method to assess the in vivo pharmacokinetic and pharmacodynamic parameters of two experimental gene-based therapies that aimed to restore GALT activity in a mouse model of galactosemia. Although our results illustrated the long-lasting efficacy of AAVrh10-mediated GALT gene transfer, we found that GALT mRNA therapy that targets the liver predominantly is sufficient to sustain WBGO. The latter could have important implications in the design of novel targeted therapy to ensure optimal efficacy and safety.
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Affiliation(s)
- Bijina Balakrishnan
- Division of Medical Genetics, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT 84108, USA
| | | | | | - Olivia Bellagamba
- Division of Medical Genetics, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT 84108, USA
| | - Aaron Guo
- Division of Medical Genetics, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT 84108, USA
| | | | | | | | | | | | | | - Yiman Wu
- Moderna, Cambridge, MA 02139, USA
| | | | | | | | | | - Kent Lai
- Division of Medical Genetics, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT 84108, USA
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3
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Almenabawy N, Bahl S, Ostlund AL, Ghai-Jain S, Sosova I, Chan A, Mercimek-Andrews S. Clinical and biochemical phenotypes, genotypes, and long-term outcomes of individuals with galactosemia type I from a single metabolic genetics center in Alberta. Mol Genet Metab Rep 2024; 38:101055. [PMID: 38469090 PMCID: PMC10926219 DOI: 10.1016/j.ymgmr.2024.101055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/12/2024] [Accepted: 01/15/2024] [Indexed: 03/13/2024] Open
Abstract
Background Galactosemia type I is an autosomal recessive disorder of galactose metabolism due to galactose-1-phosphate uridyltransferase deficiency, encoded by GALT. To investigate the phenotypes, genotypes and long-term outcomes of galactosemia, we performed a retrospective cohort study in our center. Methods All individuals with galactosemia type I were included. We divided individuals into two groups to compare the outcomes of those treated symptomatically (SymX) and asymptomatically (AsymX). We reviewed electronic patient charts for clinical features, biochemical investigations, molecular genetic investigations, treatments, and outcomes. Results There were 25 individuals including classic (n = 17), clinical variant (n = 4), and biochemical variant (Duarte) galactosemia (n = 4). Twelve individuals were diagnosed symptomatically (SymX), and 9 individuals were diagnosed asymptomatically (AsymX). We did not include individuals with biochemical variant (Duarte) galactosemia into any of these groups. At the time of the diagnosis, conjugated hyperbilirubinemia was present in 83.3% of SymX group, whereas only 22% of AsymX group. SymX group had hepatomegaly (25%), failure to thrive (33.3%), cataract (16.7%) and sepsis (25%), whereas none of the individuals in the AsymX group had these clinical features. Fourteen variants in GALT were identified including pathogenic/likely pathogenic (n = 12), and likely benign/benign (n = 2) variants. The vast majority of individuals with classic and clinical variant galactosemia were treated with a galactose-lactose-free diet for life (n = 20/21). Intellectual disability was present in 54.5% of the SymX group, and in 37.5% of the AsymX group as a long-term outcome. Tremors were present 50% of the SymX group, and in 22% of the AsymX group as a long-term outcome. Although, intellectual disability and tremors seem to be less common in the AsymX group, there was no statistically significant difference between both groups. Primary ovarian insufficiency was present 50% of the SymX group, whereas in 20% of the AsymX group in post-pubertal females. We report a novel hypomorphic GALT variant (p.Ala303Ser) in one individual with clinical variant galactosemia. We also report an individual with clinical variant galactosemia with normal urine galactitol levels on a normal diet. Conclusion It seems that newborn screening and early administration of a galactose-lactose-free diet decreases the long-term galactosemia-associated complications but does not prevent them completely. It may be that not all individuals with clinical variant galactosemia may need a galactose-lactose-free diet. It is timely to find new therapeutic strategies that can reduce the frequency of late-onset complications in galactosemia.
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Affiliation(s)
- Nihal Almenabawy
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Shalini Bahl
- Princess Margaret Cancer Centre, 101 College Street, Toronto, ON M5G 1L7, Canada
- Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Alyssa-Lyn Ostlund
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Shailly Ghai-Jain
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Iveta Sosova
- Alberta Newborn Screening and Biochemical Genetics Laboratory, University of Alberta Hospital, Alberta Precision Laboratories, Edmonton, AB, Canada
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, Canada
| | - Alicia Chan
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Saadet Mercimek-Andrews
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
- Alberta Health Services, AB, Canada
- Women's and Children's Research Institute, University of Alberta, Canada
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4
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Fridovich-Keil JL, Berry GT. Pathophysiology of long-term complications in classic galactosemia: What we do and do not know. Mol Genet Metab 2022; 137:33-39. [PMID: 35882174 DOI: 10.1016/j.ymgme.2022.07.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/04/2022] [Accepted: 07/05/2022] [Indexed: 02/04/2023]
Abstract
Despite many decades of research involving both human subjects and model systems, the underlying pathophysiology of long-term complications in classic galactosemia (CG) remains poorly understood. In this review, intended for those already familiar with galactosemia, we focus on the big questions relating to outcomes, mechanism, and markers, drawing on relevant literature where available, attempting to navigate inconsistencies where they appear, and acknowledging gaps in knowledge where they persist.
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Affiliation(s)
| | - Gerard T Berry
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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Lee S, Jeong D, Lee S, Nam S, Lee W. A Highly Sensitive Amperometric Galactose Biosensor Based on Graphene‐doped Sol‐gel‐derived Titania‐Nafion Composite Films. ELECTROANAL 2021. [DOI: 10.1002/elan.202100357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Sumin Lee
- Department of Chemistry Yonsei University Seoul 120-749, Republic of Korea
| | - Daeho Jeong
- Department of Chemistry Yonsei University Seoul 120-749, Republic of Korea
| | - Sangjung Lee
- Department of Chemistry Yonsei University Seoul 120-749, Republic of Korea
| | - Sungju Nam
- Department of Chemistry Yonsei University Seoul 120-749, Republic of Korea
| | - Won‐Yong Lee
- Department of Chemistry Yonsei University Seoul 120-749, Republic of Korea
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6
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Banford S, McCorvie TJ, Pey AL, Timson DJ. Galactosemia: Towards Pharmacological Chaperones. J Pers Med 2021; 11:jpm11020106. [PMID: 33562227 PMCID: PMC7914515 DOI: 10.3390/jpm11020106] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 02/02/2021] [Accepted: 02/04/2021] [Indexed: 02/07/2023] Open
Abstract
Galactosemia is a rare inherited metabolic disease resulting from mutations in the four genes which encode enzymes involved in the metabolism of galactose. The current therapy, the removal of galactose from the diet, is inadequate. Consequently, many patients suffer lifelong physical and cognitive disability. The phenotype varies from almost asymptomatic to life-threatening disability. The fundamental biochemical cause of the disease is a decrease in enzymatic activity due to failure of the affected protein to fold and/or function correctly. Many novel therapies have been proposed for the treatment of galactosemia. Often, these are designed to treat the symptoms and not the fundamental cause. Pharmacological chaperones (PC) (small molecules which correct the folding of misfolded proteins) represent an exciting potential therapy for galactosemia. In theory, they would restore enzyme function, thus preventing downstream pathological consequences. In practice, no PCs have been identified for potential application in galactosemia. Here, we review the biochemical basis of the disease, identify opportunities for the application of PCs and describe how these might be discovered. We will conclude by considering some of the clinical issues which will affect the future use of PCs in the treatment of galactosemia.
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Affiliation(s)
- Samantha Banford
- South Eastern Health and Social Care Trust, Downpatrick BT30 6RL, UK;
| | - Thomas J. McCorvie
- Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, UK;
| | - Angel L. Pey
- Departamento de Química Física, Unidad de Excelencia de Química aplicada a Biomedicina y Medioambiente e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain;
| | - David J. Timson
- School of Pharmacy and Biomolecular Sciences, The University of Brighton, Brighton BN2 4GJ, UK
- Correspondence:
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Crespo C, Eiroa H, Otegui MI, Bonetto MC, Chertkoff L, Gravina LP. Molecular analysis of GALT gene in Argentinian population: Correlation with enzyme activity and characterization of a novel Duarte-like allele. Mol Genet Metab Rep 2020; 25:100695. [PMID: 33335841 PMCID: PMC7733017 DOI: 10.1016/j.ymgmr.2020.100695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/29/2020] [Accepted: 12/01/2020] [Indexed: 11/02/2022] Open
Abstract
Background Classical galactosemia is an autosomal recessive inherited metabolic disorder caused by mutations in the galactose-1-phosphate uridyltransferase (GALT) gene. GALT enzyme deficiency leads to the accumulation of galactose-1-phosphate in various organs, causing hepatic, renal and cerebral impairment. Over 300 mutations have been reported in the GALT gene. The aim of this study was to describe molecular characterization of GALT gene in Argentinian patients with decreased GALT activity, and to correlate molecular results with enzyme activity. Methods 37 patients with enzyme activity below 6.3 μmol/h/g Hb (35% of normal value) were included. GALT activity was measured on red blood cells. DNA was extracted from peripheral blood. p.Gln188Arg mutation was studied by PCR-RFLP and, on samples negative or heterozygous, GALT gene was sequenced. In vivo splicing analysis of the GALT gene was performed on RNA extracted from leukocytes of one patient. Results 14 different sequence variations were identified among 72 unrelated alleles. The two most common disease-causing mutations were p.Gln188Arg (24/72) and p.Lys285Asn (9/72). Three novel mutations were detected. One of them, c.688G>A, caused partial skipping of exon 9 of the GALT gene. Enzyme activity correlated with GALT genotype in 36 of the 37 patients. Conclusion This is the first report of sequence variations in the GALT gene in the Argentinian population. This study highlights the contribution of the molecular analysis to the diagnosis of Galactosemia and reveals c.688G>A as a novel Duarte-like variant, with a high prevalence in our population.
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Affiliation(s)
- Carolina Crespo
- Laboratorio de Biología Molecular, Servicio de Genética, Hospital de Pediatría "Prof. Dr. Juan P. Garrahan", Buenos Aires, Argentina
| | - Hernán Eiroa
- Servicio de Errores Congénitos del Metabolismo, Hospital de Pediatría "Prof. Dr. Juan P. Garrahan", Buenos Aires, Argentina
| | - María Inés Otegui
- Laboratorio de Errores Congénitos del Metabolismo, Hospital de Pediatría "Prof. Dr. Juan P. Garrahan", Buenos Aires, Argentina
| | - Mara Cecilia Bonetto
- Laboratorio de Biología Molecular, Servicio de Genética, Hospital de Pediatría "Prof. Dr. Juan P. Garrahan", Buenos Aires, Argentina
| | - Lilien Chertkoff
- Área de Laboratorios de Especialidades, Hospital de Pediatría "Prof. Dr. Juan P. Garrahan", Buenos Aires, Argentina
| | - Luis Pablo Gravina
- Laboratorio de Biología Molecular, Servicio de Genética, Hospital de Pediatría "Prof. Dr. Juan P. Garrahan", Buenos Aires, Argentina
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Latchman K, Brown J, Sineni CJ, Ragin-Dames L, Guo S, Huang J, Thorson W, Hacker S, Barbouth D, Tekin M, Bademci G. A founder noncoding GALT variant interfering with splicing causes galactosemia. J Inherit Metab Dis 2020; 43:1199-1204. [PMID: 32748411 DOI: 10.1002/jimd.12293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/23/2020] [Accepted: 07/28/2020] [Indexed: 11/08/2022]
Abstract
Galactosemia is a rare, treatable hereditary disorder of carbohydrate metabolism. We investigated the etiology of decreased GALT enzyme activity in a cohort of newborns referred by the Florida Newborn Screening Program with no detectable GALT variants in diagnostic molecular tests. Six affected individuals from four families with Guatemalan heritage were included. GALT enzyme activity ranged from 20% to 34% of normal. Clinical findings were unremarkable except for speech delay in two children. Via genome sequencing followed by Sanger confirmation we showed that all affected individuals were homozygous for a deep intronic GALT variant, c.1059+390A>G, which segregated as an autosomal recessive trait in all families. The intronic variant disrupts splicing and leads to a premature termination and is associated with a single haplotype flanking GALT, suggesting a founder effect. In conclusion, we present a deep intronic GALT variant leading to a biochemical variant form of galactosemia. This variant remains undiagnosed until it is specifically targeted in molecular testing.
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Affiliation(s)
- Kumarie Latchman
- Division of Clinical and Translational Genetics, Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Jeanette Brown
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Claire J Sineni
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Lorrien Ragin-Dames
- Division of Clinical and Translational Genetics, Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Shengru Guo
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Jingyu Huang
- Division of Clinical and Translational Genetics, Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Willa Thorson
- Division of Clinical and Translational Genetics, Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Stephanie Hacker
- Division of Clinical and Translational Genetics, Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Deborah Barbouth
- Division of Clinical and Translational Genetics, Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Mustafa Tekin
- Division of Clinical and Translational Genetics, Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida, USA
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Guney Bademci
- Division of Clinical and Translational Genetics, Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida, USA
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, USA
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El Bakly W, Medhat M, Shafei M, Tash R, Elrefai M, Shoukry Y, Omar NN. Optimized platelet rich plasma releasate (O-rPRP) repairs galactosemia-induced ovarian follicular loss in rats by activating mTOR signaling and inhibiting apoptosis. Heliyon 2020; 6:e05006. [PMID: 33005806 PMCID: PMC7509792 DOI: 10.1016/j.heliyon.2020.e05006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 08/25/2020] [Accepted: 09/17/2020] [Indexed: 11/30/2022] Open
Abstract
Platelet rich plasma contains a collection of growth factors, and an optimal formulation, named O-rPRP, contains the highest possible concentration of growth factors. Purpose Challenging the healing power of O-rPRP in a high-galactose diet-induced premature ovarian insufficiency (POI) experimental rat model. Methods Rats were divided into four groups of ten rats each and treated for four week as follows; 1) the control group, fed with normal diet and received intraperitoneal (i.p.) injection of PBS once/week; 2) the POI group, fed with galactose diet (50%) and received PBS (i.p.) once/week; 3) the POI/O-rPRP group, fed a 50% galactose diet and received O-rPRP (i.p.) once/week; 4) the O-rPRP group (negative control), fed with a normal diet and received O-rPRP (i.p.) once/week. The levels of galactose, follicle stimulating hormone, 17 β-estradiol, anti-mullerian hormone and inhibin B were measured in serum samples. Western blotting and quantitative real-time PCR assays were employed to investigate the levels of miR-223, β1 integrin, p70S6k and MCL-1 in ovarian tissues. Results After O-rPRP treatment, β1 integrin expression was enhanced, and miR-223 expression was decreased. Unlike the untreated galactose group, in the group treated with O-rPRP, p70S6k and MCL-1 expression levels were increased, indicating that the mTOR growth signaling pathway was active and that apoptosis was inactive. After the introduction of O-rPRP, the number of follicles and the follicular maturation improved, which was consistent with the improvement of inhibin B levels and subsequent inhibition of FSH. Conclusion O-rPRP inhibited galactose-induced excessive atresia and provided an overall protective effect on the ovarian follicles.
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Affiliation(s)
- Wesam El Bakly
- Department of Pharmacology, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Marwa Medhat
- Department of Pharmacology, National Center for Social & Criminological Research, Egypt
| | - Mohamed Shafei
- Obstetrician and Gynecologist at Sidnawy Health Insurance Hospital, Cairo, Egypt.,Dar Alshifa Hospital, Kuwait
| | - Reham Tash
- Department of Anatomy and Embryology, Faculty of Medicine, Ain Shams University, Cairo, Egypt.,Department of Anatomy and Embryology, Faculty of Medicine in Rabigh, King Abdulaziz University, Saudi Arabia
| | - Mohamed Elrefai
- Department of Anatomy and Embryology, Faculty of Medicine, Ain Shams University, Cairo, Egypt.,Basic Medical Science Department, Faculty of Medicine, Hashemite University, Alzarqa, Jordan
| | - Yousef Shoukry
- Department of Anatomy and Embryology, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Nesreen Nabil Omar
- Department of Biochemistry, Faculty of Pharmacy, Modern University for Technology and Information, 11 Saudia Buildings, Nozha Street, 11371, Cairo, Egypt
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10
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Yuzyuk T, Wilson AR, Mao R, Pasquali M. Galactose-1-Phosphate Uridyltransferase Activities in Different Genotypes: A Retrospective Analysis of 927 Samples. J Appl Lab Med 2019; 3:222-230. [DOI: 10.1373/jalm.2017.025536] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 01/29/2018] [Indexed: 11/06/2022]
Abstract
Abstract
Background
Classic galactosemia is an inherited disorder of galactose metabolism caused by the impaired activity of galactose-1-phosphate uridyltransferase (GALT). Untreated galactosemia is life-threatening; however, early dietary intervention prevents mortality and reduces morbidity associated with this disease. The diagnosis of galactosemia includes the measurement of GALT activity in red blood cells (RBC) and GALT gene analysis. In this study, we evaluate GALT activity in different genotypes using the results of combined biochemical and molecular testing in 927 samples.
Methods
GALT activity in RBC was measured by LC-MS/MS. The analysis of the GALT gene was performed by targeted gene analysis and/or full gene sequencing. Samples were assigned based on the presence of pathogenic (G) or Duarte 2 (D) variants, or their absence (Neg), to G/G, D/G, G/Neg, D/D, D/Neg, and Neg/Neg genotypes. Finite mixture models were applied to investigate distributions of GALT activities in these genotypes. The reference ranges were determined using the central 95% of values of GALT activities.
Results
The ranges of GALT activity in G/G, D/G, G/Neg, D/D, D/Neg, and Neg/Neg genotypes are 0.0 to 0.7 μmol·h−1 gHb−1, 3.1 to 7.8 μmol·h−1 gHb−1, 6.5 to 16.2 μmol·h−1 gHb−1, 6.4 to 16.5 μmol·h−1 gHb−1, 12.0 to 24.0 μmol·h−1 gHb−1, and 19.4 to 33.4 μmol·h−1 gHb−1, respectively.
Conclusions
The GALT activity ranges established in this study are in agreement with the expected impact of the genotype on the enzymatic activity. Molecular findings should be interpreted in view of biochemical results to confirm genotype–phenotype correlation.
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Affiliation(s)
- Tatiana Yuzyuk
- Department of Pathology, University of Utah, Salt Lake City, UT
- ARUP Laboratories, Salt Lake City, UT
| | - Andrew R Wilson
- School of Nursing, University of Utah Health Sciences Center, Salt Lake City, UT
| | - Rong Mao
- Department of Pathology, University of Utah, Salt Lake City, UT
- ARUP Laboratories, Salt Lake City, UT
| | - Marzia Pasquali
- Department of Pathology, University of Utah, Salt Lake City, UT
- ARUP Laboratories, Salt Lake City, UT
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11
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Balakrishnan B, An D, Nguyen V, DeAntonis C, Martini PGV, Lai K. Novel mRNA-Based Therapy Reduces Toxic Galactose Metabolites and Overcomes Galactose Sensitivity in a Mouse Model of Classic Galactosemia. Mol Ther 2019; 28:304-312. [PMID: 31604675 DOI: 10.1016/j.ymthe.2019.09.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 09/04/2019] [Accepted: 09/12/2019] [Indexed: 11/19/2022] Open
Abstract
Classic galactosemia (CG) is a potentially lethal inborn error of galactose metabolism that results from deleterious mutations in the human galactose-1 phosphate uridylyltransferase (GALT) gene. Previously, we constructed a GalT-/- (GalT-deficient) mouse model that exhibits galactose sensitivity in the newborn mutant pups, reduced fertility in adult females, impaired motor functions, and growth restriction in both sexes. In this study, we tested whether restoration of hepatic GALT activity alone could decrease galactose-1 phosphate (gal-1P) and plasma galactose in the mouse model. The administration of different doses of mouse GalT (mGalT) mRNA resulted in a dose-dependent increase in mGalT protein expression and enzyme activity in the liver of GalT-deficient mice. Single intravenous (i.v.) dose of human GALT (hGALT) mRNA decreased gal-1P in mutant mouse liver and red blood cells (RBCs) within 24 h with low levels maintained for over a week. Repeated i.v. injections increased hepatic GalT expression, nearly normalized gal-1P levels in liver, and decreased gal-1P levels in RBCs and peripheral tissues throughout all doses. Moreover, repeated dosing reduced plasma galactose by 60% or more throughout all four doses. Additionally, a single intraperitoneal dose of hGALT mRNA overcame the galactose sensitivity and promoted the growth in a GalT-/- newborn pup.
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Affiliation(s)
- Bijina Balakrishnan
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, UT 84108, USA
| | - Ding An
- Moderna, Inc., Cambridge, MA 02139, USA
| | - Vi Nguyen
- Moderna, Inc., Cambridge, MA 02139, USA
| | | | | | - Kent Lai
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, UT 84108, USA.
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12
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Ohlsson A, Hunt M, Wedell A, von Döbeln U. Heterogeneity of disease-causing variants in the Swedish galactosemia population: Identification of 16 novel GALT variants. J Inherit Metab Dis 2019; 42:1008-1018. [PMID: 31194895 DOI: 10.1002/jimd.12136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 06/10/2019] [Accepted: 06/11/2019] [Indexed: 11/11/2022]
Abstract
The aim was to determine disease-causing variants in the GALT gene which codes for the enzyme galactose-1-phosphate uridylyltransferase. Loss of activity of this enzyme causes classical galactosemia-a life threatening, treatable disorder, included in the Swedish newborn screening program since 1967. A total of 66 patients with the disease are known in Sweden and 56 index patients were investigated. An additional two patients with Duarte galactosemia were included. The disease-causing variants were identified in all patients. As reported from other countries only a few variants frequently recur in severe disease. The two variants p.(Gln188Arg) (c.563A>G) and p.(Met142Lys) (c.425T>A) are present in several index patients whereas the remaining are found in one to three patients each. The most common variant, p.(Gln188Arg), has an allele frequency of 51% in the cohort. A total of 16 novel variants were found among the 33 different variants in the cohort. Two of these are synonymous variants affecting splicing, demonstrating the importance of the evaluation of synonymous variants at the cDNA level. Concise sentence: Galactosemia is a rare disease in Sweden and the disease-causing variants are heterogenous including two synonymous variants.
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Affiliation(s)
- Annika Ohlsson
- Centre for Inherited Metabolic Diseases (CMMS), Karolinska University Hospital, Stockholm, Sweden
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Mary Hunt
- The School of Biological and Health Sciences, Dublin Institute of Technology, Dublin, Ireland
| | - Anna Wedell
- Centre for Inherited Metabolic Diseases (CMMS), Karolinska University Hospital, Stockholm, Sweden
- Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden
| | - Ulrika von Döbeln
- Centre for Inherited Metabolic Diseases (CMMS), Karolinska University Hospital, Stockholm, Sweden
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
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13
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Canson DM, Silao CLT, Caoili SEC. Functional analysis of GALT variants found in classic galactosemia patients using a novel cell-free translation method. JIMD Rep 2019; 48:60-66. [PMID: 31392114 PMCID: PMC6606980 DOI: 10.1002/jmd2.12037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 04/04/2019] [Accepted: 04/18/2019] [Indexed: 11/15/2022] Open
Abstract
Classic galactosemia is an autosomal recessive disorder caused by deleterious variants in the galactose-1-phosphate uridylyltransferase (GALT) gene. GALT enzyme deficiency leads to an increase in the levels of galactose and its metabolites in the blood causing neurodevelopmental and other clinical complications in affected individuals. Two GALT variants NM_000155.3:c.347T>C (p.Leu116Pro) and NM_000155.3:c.533T>G (p.Met178Arg) were previously detected in Filipino patients. Here, we determine their functional effects on the GALT enzyme through in silico analysis and a novel experimental approach using a HeLa-based cell-free protein expression system. Enzyme activity was not detected for the p.Leu116Pro protein variant, while only 4.5% of wild-type activity was detected for the p.Met178Arg protein variant. Computational analysis of the variants revealed destabilizing structural effects and suggested protein misfolding as the potential mechanism of enzymological impairment. Biochemical and computational data support the classification of p.Leu116Pro and p.Met178Arg variants as pathogenic. Moreover, the protein expression method developed has utility for future studies of GALT variants.
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Affiliation(s)
- Daffodil M. Canson
- Institute of Human Genetics, National Institutes of HealthUniversity of the Philippines ManilaManilaPhilippines
- Department of Biochemistry and Molecular Biology, College of MedicineUniversity of the Philippines ManilaManilaPhilippines
| | - Catherine Lynn T. Silao
- Institute of Human Genetics, National Institutes of HealthUniversity of the Philippines ManilaManilaPhilippines
| | - Salvador Eugenio C. Caoili
- Department of Biochemistry and Molecular Biology, College of MedicineUniversity of the Philippines ManilaManilaPhilippines
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14
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Papachristoforou R, Petrou PP, Sawyer H, Williams M, Drousiotou A. Classic galactosaemia in the Greek Cypriot population: An epidemiological and molecular study. Ann Hum Genet 2019; 83:291-298. [PMID: 30994193 PMCID: PMC6766971 DOI: 10.1111/ahg.12318] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 03/15/2019] [Accepted: 03/25/2019] [Indexed: 11/27/2022]
Abstract
Classic galactosaemia is an inherited metabolic disorder of galactose metabolism caused by deficiency of the enzyme galactose-1-phosphate uridyltransferase (GALT) resulting from mutations in the GALT gene. The objectives of the present study were the determination of the carrier frequency of classic galactosaemia in the Greek Cypriot population and the molecular characterization of the disease alleles. We performed an epidemiological study involving 528 Greek Cypriots originating from all parts of Cyprus. Carriers were identified by measuring GALT activity in red blood cells and were subsequently subjected to mutation analysis. A total of five mutations were identified in patients and carriers of classic galactosaemia: a large deletion of 8.5 kb previously reported by us (55% of alleles), the known mutations p.Lys285Asn (30%), p.Pro185Ser (5%), and c.820+13A>G (5%), and a novel mutation c.378-12G>A (5%). Interestingly, the most common mutation in European populations, p.Gln188Arg, was not identified in this Cypriot cohort. The carrier frequency for classic galactosaemia among Greek Cypriots was estimated to be 1:88, predicting a homozygote incidence of 1:31,000 births. The Duarte 1 and Duarte 2 variants were found to be present at a frequency of 5.5% and 2.5%, respectively.
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Affiliation(s)
- Rena Papachristoforou
- Department of Biochemical Genetics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Petros P Petrou
- Department of Biochemical Genetics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus.,The Cyprus School of Molecular Medicine, Nicosia, Cyprus
| | - Hilary Sawyer
- Bristol Genetics Laboratory, Southmead Hospital, Bristol, United Kingdom
| | - Maggie Williams
- Bristol Genetics Laboratory, Southmead Hospital, Bristol, United Kingdom
| | - Anthi Drousiotou
- Department of Biochemical Genetics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus.,The Cyprus School of Molecular Medicine, Nicosia, Cyprus
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15
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Grama A, Blaga L, Nicolescu A, Deleanu C, Militaru M, Căinap SS, Pop I, Tita G, Sîrbe C, Fufezan O, Vințan MA, Vulturar R, Pop TL. Novel Mutation in GALT Gene in Galactosemia Patient with Group B Streptococcus Meningitis and Acute Liver Failure. ACTA ACUST UNITED AC 2019; 55:medicina55040091. [PMID: 30987402 PMCID: PMC6524007 DOI: 10.3390/medicina55040091] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 03/14/2019] [Accepted: 04/01/2019] [Indexed: 02/05/2023]
Abstract
Classic galactosemia is an autosomal recessive disorder caused by the deficiency of the enzyme galactose-1-phosphate uridyltransferase (GALT) involved in galactose metabolism. Bacterial infections are a known cause of early morbidity and mortality in children with classic galactosemia. The most common agent is Escherichia coli, but in rare situations, other bacteria are incriminated. We report a case of a three-week-old female patient with galactosemia, who presented with Group B Streptococcus (GBS) meningitis/sepsis. She received treatment with antibiotics, supportive therapy, and erythrocyte transfusion, but after a short period of improvement, she presented acute liver failure with suspicion of an inborn error of metabolism. Rapid nuclear magnetic resonance (NMR) spectroscopy from urine showed highly elevated values of galactose and galactitol. Under intensive treatment for acute liver failure and with a lactose-free diet, her clinical features and laboratory parameters improved considerably. Genetic testing confirmed compound heterozygous status for GALT mutations: c.563 A>G [p.Q188R] and c. 910 C>T, the last mutation being a novel mutation in GALT gene. In countries without an extensive newborn screening program, a high index of suspicion is necessary for early diagnosis and treatment of galactosemia.
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Affiliation(s)
- Alina Grama
- Second Pediatric Clinic, Department of Mother and Child, University of Medicine and Pharmacy "Iuliu Hațieganu" Cluj-Napoca, 400012 Cluj-Napoca, Romania.
| | - Ligia Blaga
- Discipline of Neonatology, Department of Mother and Child, University of Medicine and Pharmacy "Iuliu Hațieganu" Cluj-Napoca, 400012 Cluj-Napoca, Romania.
| | - Alina Nicolescu
- NMR Laboratory, "Petru Poni" Institute of Macromolecular Chemistry, Romanian Academy of Sciences, 700487 Iaşi, Romania.
- "Costin D. Neniţescu" Institute of Organic Chemistry, Romanian Academy of Sciences, 060023 Bucharest, Romania.
| | - Călin Deleanu
- NMR Laboratory, "Petru Poni" Institute of Macromolecular Chemistry, Romanian Academy of Sciences, 700487 Iaşi, Romania.
- "Costin D. Neniţescu" Institute of Organic Chemistry, Romanian Academy of Sciences, 060023 Bucharest, Romania.
| | - Mariela Militaru
- Medical Genetics, Department of Molecular Sciences, University of Medicine and Pharmacy "Iuliu Hațieganu" Cluj-Napoca, 400012 Cluj-Napoca, Romania.
- Genetic Center Cluj-Napoca, 400363 Cluj-Napoca, Romania.
| | - Simona Sorana Căinap
- Second Pediatric Clinic, Department of Mother and Child, University of Medicine and Pharmacy "Iuliu Hațieganu" Cluj-Napoca, 400012 Cluj-Napoca, Romania.
| | - Irina Pop
- Second Pediatric Clinic, Department of Mother and Child, University of Medicine and Pharmacy "Iuliu Hațieganu" Cluj-Napoca, 400012 Cluj-Napoca, Romania.
| | - Georgia Tita
- Second Pediatric Clinic, Department of Mother and Child, University of Medicine and Pharmacy "Iuliu Hațieganu" Cluj-Napoca, 400012 Cluj-Napoca, Romania.
| | - Claudia Sîrbe
- Second Pediatric Clinic, Department of Mother and Child, University of Medicine and Pharmacy "Iuliu Hațieganu" Cluj-Napoca, 400012 Cluj-Napoca, Romania.
| | - Otilia Fufezan
- Radiology Department, Children's Emergency Clinical Hospital, Cluj-Napoca, 400378, Romania.
| | - Mihaela Adela Vințan
- Pediatric Neurology Clinic, Children's Emergency Clinical Hospital, Department of Neurosciences, University of Medicine and Pharmacy "Iuliu Hațieganu" Cluj-Napoca, 400012 Cluj-Napoca, Romania.
| | - Romana Vulturar
- Department of Molecular Sciences, University of Medicine and Pharmacy "Iuliu Hațieganu" Cluj-Napoca, 400012 Cluj-Napoca, Romania.
- Cognitive Neuroscience Laboratory, Department of Psychology, Babeş-Bolyai University, Cluj-Napoca, 400084 Cluj-Napoca, Romania.
- Imogen Medical Institute, 400012 Cluj-Napoca, Romania.
| | - Tudor Lucian Pop
- Second Pediatric Clinic, Department of Mother and Child, University of Medicine and Pharmacy "Iuliu Hațieganu" Cluj-Napoca, 400012 Cluj-Napoca, Romania.
- Center of Expertise for Pediatric Liver Rare Disorders, Children's Emergency Clinical Hospital, 400177 Cluj-Napoca, Romania.
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16
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Yuzyuk T, Balakrishnan B, Schwarz EL, De Biase I, Hobert J, Longo N, Mao R, Lai K, Pasquali M. Effect of genotype on galactose-1-phosphate in classic galactosemia patients. Mol Genet Metab 2018; 125:258-265. [PMID: 30172461 DOI: 10.1016/j.ymgme.2018.08.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/21/2018] [Accepted: 08/22/2018] [Indexed: 11/27/2022]
Abstract
Impaired activity of galactose-1-phosphate uridyltransferase (GALT) causes classic galactosemia (OMIM 230400), characterized by the accumulation of galactose-1-phosphate (GAL1P) in patients' red blood cells (RBCs). Our recent study demonstrated a correlation between RBC GAL1P and long-term outcomes in galactosemia patients. Here, we analyze biochemical and molecular results in 77 classic galactosemia patients to evaluate the association between GALT genotypes and GAL1P concentration in RBCs. Experimental data from model organisms were also included to assess the correlation between GAL1P and predicted residual activity of each genotype. Although all individuals in this study showed markedly reduced RBC GALT activity, we observed significant differences in RBC GAL1P concentrations among galactosemia genotypes. While levels of GAL1P on treatment did not correlate with RBC GALT activities (p = 0.166), there was a negative nonlinear correlation between mean GAL1P concentrations and predicted residual enzyme activity of genotype (p = 0.004). These studies suggest that GAL1P levels in RBCs on treatment likely reflect the overall functional impairment of GALT in patients with galactosemia.
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Affiliation(s)
- Tatiana Yuzyuk
- Department of Pathology, University of Utah, Salt Lake City, UT, USA; ARUP Laboratories, Salt Lake City, UT, USA.
| | - Bijina Balakrishnan
- Division of Medical Genetics/Pediatrics, University of Utah, Salt Lake City, UT, USA
| | | | - Irene De Biase
- Department of Pathology, University of Utah, Salt Lake City, UT, USA; ARUP Laboratories, Salt Lake City, UT, USA
| | - Judith Hobert
- Department of Pathology, University of Utah, Salt Lake City, UT, USA; ARUP Laboratories, Salt Lake City, UT, USA
| | - Nicola Longo
- Department of Pathology, University of Utah, Salt Lake City, UT, USA; ARUP Laboratories, Salt Lake City, UT, USA; Division of Medical Genetics/Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Rong Mao
- Department of Pathology, University of Utah, Salt Lake City, UT, USA; ARUP Laboratories, Salt Lake City, UT, USA
| | - Kent Lai
- Division of Medical Genetics/Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Marzia Pasquali
- Department of Pathology, University of Utah, Salt Lake City, UT, USA; ARUP Laboratories, Salt Lake City, UT, USA
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P S, Ebrahimi EA, Ghazala SA, D TK, R S, Priya Doss C G, Zayed H. Structural analysis of missense mutations in galactokinase 1 (GALK1) leading to galactosemia type-2. J Cell Biochem 2018; 119:7585-7598. [PMID: 29893426 DOI: 10.1002/jcb.27097] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/26/2018] [Indexed: 12/27/2022]
Abstract
Galactosemia type 2 is an autosomal recessive disorder characterized by the deficiency of galactokinase (GALK) enzyme due to missense mutations in GALK1 gene, which is associated with various manifestations such as hyper galactosemia and formation of cataracts. GALK enzyme catalyzes the adenosine triphosphate (ATP)-dependent phosphorylation of α-d-galactose to galactose-1-phosphate. We searched 4 different literature databases (Google Scholar, PubMed, PubMed Central, and Science Direct) and 3 gene-variant databases (Online Mendelian Inheritance in Man, Human Gene Mutation Database, and UniProt) to collect all the reported missense mutations associated with GALK deficiency. Our search strategy yielded 32 missense mutations. We used several computational tools (pathogenicity and stability, biophysical characterization, and physiochemical analyses) to prioritize the most significant mutations for further analyses. On the basis of the pathogenicity and stability predictions, 3 mutations (P28T, A198V, and L139P) were chosen to be tested further for physicochemical characterization, molecular docking, and simulation analyses. Molecular docking analysis revealed a decrease in interaction between the protein and ATP in all the 3 mutations, and molecular dynamic simulations of 50 ns showed a loss of stability and compactness in the mutant proteins. As the next step, comparative physicochemical changes of the native and the mutant proteins were carried out using essential dynamics. Overall, P28T and A198V were predicted to alter the structure and function of GALK protein when compared to the mutant L139P. This study demonstrates the power of computational analysis in variant classification and interpretation and provides a platform for developing targeted therapeutics.
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Affiliation(s)
- Sneha P
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, India
| | - Elaheh Ahmad Ebrahimi
- Department of Biomedical Sciences, College of Health Sciences, Qatar University, Doha, Qatar
| | - Sara Ahmed Ghazala
- Department of Biomedical Sciences, College of Health Sciences, Qatar University, Doha, Qatar
| | - Thirumal Kumar D
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, India
| | - Siva R
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, India
| | - George Priya Doss C
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, India
| | - Hatem Zayed
- Department of Biomedical Sciences, College of Health Sciences, Qatar University, Doha, Qatar
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Yuzyuk T, Viau K, Andrews A, Pasquali M, Longo N. Biochemical changes and clinical outcomes in 34 patients with classic galactosemia. J Inherit Metab Dis 2018; 41:197-208. [PMID: 29350350 DOI: 10.1007/s10545-018-0136-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 12/19/2017] [Accepted: 01/02/2018] [Indexed: 10/18/2022]
Abstract
Impaired activity of galactose-1-phosphate uridyltransferase (GALT) causes galactosemia, an autosomal recessive disorder of galactose metabolism. Early initiation of a galactose-restricted diet can prevent or resolve neonatal complications. Despite therapy, patients often experience long-term complications including speech impairment, learning disabilities, and premature ovarian insufficiency in females. This study evaluates clinical outcomes in 34 galactosemia patients with markedly reduced GALT activity and compares outcomes between patients with different levels of mean galactose-1-phosphate in red blood cells (GAL1P) using logistic regression: group 1 (n = 13) GAL1P ≤1.7 mg/dL vs. group 2 (n = 21) GAL1P ≥ 2 mg/dL. Acute symptoms at birth were comparable between groups (p = 0.30) with approximately 50% of patients presenting with jaundice, liver failure, and failure-to-thrive. However, group 2 patients had significantly higher prevalence of negative long-term outcomes compared to group 1 patients (p = 0.01). Only one of 11 patients >3 yo in group 1 developed neurological and severe behavioral problems of unclear etiology. In contrast, 17 of 20 patients >3 yo in group 2 presented with one or more long-term complications associated with galactosemia. The majority of females ≥15 yo in this group also had impaired ovarian function with markedly reduced levels of anti-Müllerian hormone. These findings suggest that galactosemia patients with higher GAL1P levels are more likely to have negative long-term outcome. Therefore, evaluation of GAL1P levels on a galactose-restricted diet might be helpful in providing a prognosis for galactosemia patients with rare or novel genotypes whose clinical presentations are not well known.
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Affiliation(s)
- Tatiana Yuzyuk
- Department of Pathology, University of Utah, Salt Lake City, UT, USA.
- ARUP Laboratories, 500 Chipeta Way, Salt Lake City, UT, 84108, USA.
| | - Krista Viau
- Division of Medical Genetics/Pediatrics, University of Utah, Salt Lake City, UT, USA
- Boston Children's Hospital, Boston, MA, USA
| | - Ashley Andrews
- Division of Medical Genetics/Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Marzia Pasquali
- Department of Pathology, University of Utah, Salt Lake City, UT, USA
- ARUP Laboratories, 500 Chipeta Way, Salt Lake City, UT, 84108, USA
| | - Nicola Longo
- Department of Pathology, University of Utah, Salt Lake City, UT, USA
- ARUP Laboratories, 500 Chipeta Way, Salt Lake City, UT, 84108, USA
- Division of Medical Genetics/Pediatrics, University of Utah, Salt Lake City, UT, USA
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19
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Laboratory diagnosis of galactosemia: a technical standard and guideline of the American College of Medical Genetics and Genomics (ACMG). Genet Med 2017; 20:3-11. [PMID: 29261178 DOI: 10.1038/gim.2017.172] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 08/30/2017] [Indexed: 11/09/2022] Open
Abstract
Disclaimer: These ACMG Standards and Guidelines are developed primarily as an educational resource for clinical laboratory geneticists to help them provide quality clinical laboratory genetic services. Adherence to these Standards and Guidelines is voluntary and does not necessarily assure a successful medical outcome. These Standards and Guidelines should not be considered inclusive of all proper procedures and tests or exclusive of other procedures and tests that are reasonably directed to obtaining the same results. In determining the propriety of any specific procedure or test, the clinical laboratory geneticist should apply his or her own professional judgment to the specific circumstances presented by the individual patient or specimen. Clinical laboratory geneticists are encouraged to document in the patient's record the rationale for the use of a particular procedure or test, whether or not it is in conformance with these Standards and Guidelines. They also are advised to take notice of the date any particular guideline was adopted, and to consider other relevant medical and scientific information that becomes available after that date. It also would be prudent to consider whether intellectual property interests may restrict the performance of certain tests and other procedures.Galactosemias are inherited disorders of galactose metabolism due to deficiency in one of the three enzymes involved in the Leloir pathway: galactose-1-phosphate uridyltransferase, galactokinase, and uridine diphosphate (UDP)-galactose-4'-epimerase. Galactose-1-phosphate uridyltransferase deficiency, or classic galactosemia, is the most frequent and the most severe of the three enzyme deficiencies; it is characterized by failure to thrive, liver failure, susceptibility to sepsis, and death, if untreated. Newborn screening for classic galactosemia has been implemented in all of the United States, while screening for galactokinase deficiency and UDP-galactose-4'-epimerase deficiency is not universal. Early identification and treatment of galactosemia leads to improved outcome. This document reviews the laboratory methods and best practices for the diagnosis of galactosemia.
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20
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Viggiano E, Marabotti A, Politano L, Burlina A. Galactose-1-phosphate uridyltransferase deficiency: A literature review of the putative mechanisms of short and long-term complications and allelic variants. Clin Genet 2017; 93:206-215. [PMID: 28374897 DOI: 10.1111/cge.13030] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 03/29/2017] [Accepted: 03/31/2017] [Indexed: 12/30/2022]
Abstract
Galactosemia type 1 is an autosomal recessive disorder of galactose metabolism, determined by a deficiency in the enzyme galactose-1-phosphate uridyltransferase (GALT). GALT deficiency is classified as severe or variant depending on biochemical phenotype, genotype and potential to develop acute and long-term complications. Neonatal symptoms usually resolve after galactose-restricted diet; however, some patients, despite the diet, can develop long-term complications, in particular when the GALT enzyme activity results absent or severely decreased. The mechanisms of acute and long-term complications are still discussed and several hypotheses are presented in the literature like enzymatic inhibition, osmotic stress, endoplasmic reticulum stress, oxidative stress, defects of glycosylation or epigenetic modification. This review summarizes the current knowledge of galactosemia, in particular the putative mechanisms of neonatal and long-term complications and the molecular genetics of GALT deficiency.
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Affiliation(s)
- E Viggiano
- Division of Metabolic Diseases, Department of Paediatrics, University Hospital of Padua, Padua, Italy.,Cardiomyology and Medical Genetics, Department of Experimental Medicine, Second University of Naples, Naples, Italy
| | - A Marabotti
- Department of Chemistry and Biology "A. Zambelli", University of Salerno, Salerno, Italy.,Interuniversity Center "ELFID", University of Salerno, Fisciano, Italy
| | - L Politano
- Cardiomyology and Medical Genetics, Department of Experimental Medicine, Second University of Naples, Naples, Italy
| | - A Burlina
- Division of Metabolic Diseases, Department of Paediatrics, University Hospital of Padua, Padua, Italy
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21
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Schulpis KH, Thodi G, Iakovou K, Chatzidaki M, Dotsikas Y, Molou E, Triantafylli O, Loukas YL. Clinical evaluation and mutational analysis of GALK and GALE genes in patients with galactosemia in Greece: one novel mutation and two rare cases. J Pediatr Endocrinol Metab 2017; 30:775-779. [PMID: 28672748 DOI: 10.1515/jpem-2017-0065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 06/02/2017] [Indexed: 01/24/2023]
Abstract
BACKGROUND Deficiencies of galactokinase (GALK) and UDP-epimerase (GALE) are implicated with galactose metabolic disorders. The aim of the study was the identification of mutations in GALK and GALE genes and clinical evaluation of patients. METHODS Five patients with GALK and five with GALE deficiency were picked up via the Neonatal Screening Program. Additionally, two females, 4 years old, were referred with late diagnosed galactosemia, as rare cases. Mutational analysis was conducted via Sanger sequencing, while in silico analysis tools were utilized for the novel mutation. Psychomotor and speech development tests were performed, as well. RESULTS The mutation p.Pro28Thr was identified in both alleles in GALK-deficient patients of Roma (gypsy) origin, whereas the novel p.Asn39Ser was detected in two non-Roma patients. In GALE-deficient patients benign and/or likely benign mutations were found. Psychomotor and speech delay were determined in the Roma GALK patients. In each of the late diagnosed females, four mutations were identified in all galactosemia-related genes. CONCLUSIONS The mutational spectrums of GALE- and GALK-deficient patients in Greece are presented for the first time along with a clinical evaluation. Mutational analysis in all galactosemia-related genes of symptomatic patients is highly recommended for future cases.
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22
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Schulpis KH, Thodi G, Iakovou K, Chatzidaki M, Dotsikas Y, Molou E, Triantafylli O, Loukas YL. Mutational analysis of GALT gene in Greek patients with galactosaemia: identification of two novel mutations and clinical evaluation. Scandinavian Journal of Clinical and Laboratory Investigation 2017. [DOI: 10.1080/00365513.2017.1334262] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | - Georgia Thodi
- Laboratory of Prenatal and Neonatal Screening, Neoscreen Ltd, Athens, Greece
| | | | - Maria Chatzidaki
- Laboratory of Prenatal and Neonatal Screening, Neoscreen Ltd, Athens, Greece
| | - Yannis Dotsikas
- Department of Pharmacy, Laboratory of Pharm. Analysis, National and Kapodestrian University of Athens, Athens, Greece
| | - Elina Molou
- Laboratory of Prenatal and Neonatal Screening, Neoscreen Ltd, Athens, Greece
| | - Olga Triantafylli
- Laboratory of Prenatal and Neonatal Screening, Neoscreen Ltd, Athens, Greece
| | - Yannis L. Loukas
- Department of Pharmacy, Laboratory of Pharm. Analysis, National and Kapodestrian University of Athens, Athens, Greece
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23
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Rossetti R, Ferrari I, Bonomi M, Persani L. Genetics of primary ovarian insufficiency. Clin Genet 2016; 91:183-198. [PMID: 27861765 DOI: 10.1111/cge.12921] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 11/10/2016] [Accepted: 11/11/2016] [Indexed: 12/15/2022]
Abstract
Primary ovarian insufficiency (POI) is characterized by a loss of ovarian function before the age of 40 and account for one major cause of female infertility. POI relevance is continuously growing because of the increasing number of women desiring conception beyond 30 years of age, when POI prevalence is >1%. POI is highly heterogeneous and can present with ovarian dysgenesis and primary amenorrhea, or with secondary amenorrhea, and it can be associated with other congenital or acquired abnormalities. In most cases POI remains classified as idiopathic. However, the age of menopause is an inheritable trait and POI has a strong genetic component. This is confirmed by the existence of several candidate genes, experimental and natural models. The variable expressivity of POI defect may indicate that, this disease may frequently be considered as a multifactorial or oligogenic defect. The most common genetic contributors to POI are the X chromosome-linked defects. Here, we review the principal X-linked and autosomal genes involved in syndromic and non-syndromic forms of POI with the expectation that this list will soon be upgraded, thus allowing the possibility to predict the risk of an early age at menopause in families with POI.
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Affiliation(s)
- R Rossetti
- Department of Endocrine and Metabolic Diseases, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - I Ferrari
- Department of Endocrine and Metabolic Diseases, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - M Bonomi
- Department of Endocrine and Metabolic Diseases, IRCCS Istituto Auxologico Italiano, Milan, Italy.,Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - L Persani
- Department of Endocrine and Metabolic Diseases, IRCCS Istituto Auxologico Italiano, Milan, Italy.,Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
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24
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Qin B, Moorman PG, Alberg AJ, Barnholtz-Sloan JS, Bondy M, Cote ML, Funkhouser E, Peters ES, Schwartz AG, Terry P, Schildkraut JM, Bandera EV. Dairy, calcium, vitamin D and ovarian cancer risk in African-American women. Br J Cancer 2016; 115:1122-1130. [PMID: 27632371 PMCID: PMC5117784 DOI: 10.1038/bjc.2016.289] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 08/08/2016] [Accepted: 08/16/2016] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND No previous study has evaluated the associations of dairy products, lactose, calcium and vitamin D with the risk of ovarian cancer in African-American women, who are known to have high mortality from the disease, as well as to be at risk for calcium and vitamin D deficiency. METHODS We evaluated these associations among 490 ovarian cancer cases and 656 age- and site-matched controls of African-American descent recruited into the African American Cancer Epidemiology Study, a population-based case-control study in 11 geographical areas in the US. Multivariable logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS An increased ovarian cancer risk was observed for whole milk consumption and lactose intake (highest quartile vs lowest: OR=1.97, 95% CI: 1.25-3.10;P-trend: 0.008). Calcium intake was associated with a decreased risk of ovarian cancer (OR=0.51, 95 CI%: 0.30-0.86; P-trend: 0.009), but vitamin D intake was not. Longer sun exposure in summer months was found to predict a lower risk (OR=0.71, 95% CI: 0.51-0.99; P-trend: 0.049). CONCLUSIONS Our findings suggest that a high-calcium, low-lactose diet, and sun exposure in summer months may reduce the risk of ovarian cancer in African-American women.
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Affiliation(s)
- Bo Qin
- Population Science, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08903, USA
| | - Patricia G Moorman
- Department of Community and Family Medicine, Duke Cancer Institute, Durham, NC 27705, USA
| | - Anthony J Alberg
- Hollings Cancer Center and Department of Public Health Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Jill S Barnholtz-Sloan
- Case Comprehensive Cancer Center, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Melissa Bondy
- Cancer Prevention and Population Sciences Program, Baylor College of Medicine, Houston, TX 77030, USA
| | - Michele L Cote
- Department of Oncology and the Karmanos Cancer Institute, Population Studies and Disparities Research Program, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Ellen Funkhouser
- Division of Preventive Medicine, University of Alabama at Birmingham, Birmingham, AL 35205, USA
| | - Edward S Peters
- Epidemiology Program, Louisiana State University Health Sciences Center School of Public Health, New Orleans, LA 70112, USA
| | - Ann G Schwartz
- Department of Oncology and the Karmanos Cancer Institute, Population Studies and Disparities Research Program, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Paul Terry
- Departments of Public Health and Surgery, University of Tennessee-Knoxville, Knoxville, TN 37996, USA
| | - Joellen M Schildkraut
- Department of Public Health Sciences, University of Virginia, Charlottesville, VA 22908, USA
| | - Elisa V Bandera
- Population Science, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08903, USA
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25
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Varela-Lema L, Paz-Valinas L, Atienza-Merino G, Zubizarreta-Alberdi R, Villares RV, López-García M. Appropriateness of newborn screening for classic galactosaemia: a systematic review. J Inherit Metab Dis 2016; 39:633-649. [PMID: 27116003 DOI: 10.1007/s10545-016-9936-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 03/28/2016] [Accepted: 04/06/2016] [Indexed: 12/11/2022]
Abstract
Currently, there is no universal agreement on galactosaemia screening, fundamentally because of the risk-benefit uncertainties. We conducted two exhaustive systematic searches in the main electronic databases (PubMed, Embase, Cochrane, etc.) to recover relevant information about the disease and screening test/s in order to support decision making in Spain. All of the 45 studies identified that covered disease issues were retrospective case series or cross-sectional analysis (level-4 evidence). Studies consistently found that the majority of patients presented characteristic symptomatology before diagnosis. Long term disabilities were not significantly correlated with age of diagnosis, onset of dietary restriction or strict diet compliance. The five studies that provided accuracy data used different cut-off points and verification tests, and thus differed in their definitions of a positive case (level-3b evidence). The estimated sensitivity was 100 % and the specificity 99.9 %. The false-positive rate ranged from 0.0005 % to 0.25 %, and the PPV from 0 % to 64.3 %. The comparative clinical effectiveness in relation to not screening or implementation of other programs is unknown. In summary, existing evidence remains insufficient to establish the appropriateness of newborn screening for galactosaemia screening, although health benefits could be expected if early diagnosis and treatment is achieved. If screening is implemented in Spain, it would be important that a pilot programme be implemented to assess false positive rate and ensure that early diagnosis is not delayed.
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Affiliation(s)
- L Varela-Lema
- Scientific-Technical Advice Unit (avalia-t), Galician Agency for Health Knowledge Management, ACIS, Santiago de Compostela, Spain.
| | - L Paz-Valinas
- Scientific-Technical Advice Unit (avalia-t), Galician Agency for Health Knowledge Management, ACIS, Santiago de Compostela, Spain
| | - G Atienza-Merino
- Scientific-Technical Advice Unit (avalia-t), Galician Agency for Health Knowledge Management, ACIS, Santiago de Compostela, Spain
| | - R Zubizarreta-Alberdi
- Department of Innovation and Public Health, Galician Health Authority, Santiago de Compostela, Spain
| | - R Vizoso Villares
- Department of Innovation and Public Health, Galician Health Authority, Santiago de Compostela, Spain
| | - M López-García
- Scientific-Technical Advice Unit (avalia-t), Galician Agency for Health Knowledge Management, ACIS, Santiago de Compostela, Spain
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26
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Timson DJ. The molecular basis of galactosemia — Past, present and future. Gene 2016; 589:133-41. [DOI: 10.1016/j.gene.2015.06.077] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 06/18/2015] [Accepted: 06/29/2015] [Indexed: 12/19/2022]
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27
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Shaw KA, Mulle JG, Epstein MP, Fridovich-Keil JL. Gastrointestinal Health in Classic Galactosemia. JIMD Rep 2016; 33:27-32. [PMID: 27363831 DOI: 10.1007/8904_2016_575] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 04/18/2016] [Accepted: 05/23/2016] [Indexed: 01/23/2023] Open
Abstract
Classic galactosemia (CG) is an autosomal recessive disorder of galactose metabolism that affects approximately 1/50,000 live births in the USA. Following exposure to milk, which contains large quantities of galactose, affected infants may become seriously ill. Early identification by newborn screening with immediate dietary galactose restriction minimizes or prevents the potentially lethal acute symptoms of CG. However, more than half of individuals with CG still experience long-term complications including cognitive disability, behavioral problems, and speech impairment. Anecdotal reports have also suggested frequent gastrointestinal (GI) problems, but this outcome has not been systematically addressed. In this study we explored the prevalence of GI symptoms among 183 children and adults with CG (cases) and 190 controls. Cases reported 4.5 times more frequent constipation (95% CI 1.8-11.5) and 4.2 times more frequent nausea (95% CI 1.2-15.5) than controls. Cases with genotypes predicting residual GALT activity reported less frequent constipation than cases without predicted GALT activity but this difference was not statistically significant. Because the rigor of dietary galactose restriction varies among individuals with galactosemia, we further tested whether GI symptoms associated with diet in infancy. Though constipation was almost four times as common among cases reporting a more restrictive diet in infancy, this difference was not statistically significant. These data confirm that certain GI symptoms are more common in classic galactosemia compared to controls and suggest that future studies should investigate associations with residual GALT activity and dietary galactose restriction in early life.
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Affiliation(s)
- Kelly A Shaw
- Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA, USA
| | - Jennifer G Mulle
- Department of Epidemiology, Emory University School of Public Health, Atlanta, GA, USA
| | - Michael P Epstein
- Department of Human Genetics, Emory University School of Medicine, Room 325.2 Whitehead Building, 615 Michael Street, Atlanta, GA, 30322, USA
| | - Judith L Fridovich-Keil
- Department of Human Genetics, Emory University School of Medicine, Room 325.2 Whitehead Building, 615 Michael Street, Atlanta, GA, 30322, USA.
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28
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Garcia DF, Camelo JS, Molfetta GA, Turcato M, Souza CFM, Porta G, Steiner CE, Silva WA. Clinical profile and molecular characterization of Galactosemia in Brazil: identification of seven novel mutations. BMC MEDICAL GENETICS 2016; 17:39. [PMID: 27176039 PMCID: PMC4866286 DOI: 10.1186/s12881-016-0300-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 04/30/2016] [Indexed: 11/17/2022]
Abstract
Background Classical Galactosemia (CG) is an inborn error of galactose metabolism caused by the deficiency of the galactose-1-phosphate uridyltransferase enzyme. It is transmitted as an autosomal recessive disease and is typically characterized by neonatal galactose intolerance, with complications ranging from neonatal jaundice and liver failure to late complications, such as motor and reproductive dysfunctions. Galactosemia is also heterogeneous from a molecular standpoint, with hundreds of different mutations described in the GALT gene, some of them specific to certain populations, reflecting consequence of founder effect. Methods This study reviews the main clinical findings and depicts the spectrum of mutations identified in 19 patients with CG, six with Duarte Galactosemia and one with type 2 Galactosemia in Brazil. Some individuals were diagnosed through expanded newborn screening test, which is not available routinely to all newborns. Results The main classical Galactosemia mutations reported to date were identified in this study, as well as the Duarte variant and seven novel mutations - c.2 T > C (p.M1T), c.97C > A (p.R33S), c.217C > T (p.P73S), c.328 + 1G > A (IVS3 + 1G > A), c.377 + 4A > C (IVS4 + 4A > C), c.287_289delACA (p.N97del) and c.506A > C (p.Q169P). This was expected, given the high miscegenation of the Brazilian population. Conclusions This study expands the mutation spectrum in GALT gene and reinforces the importance of early diagnosis and introduction of dietary treatment, what is possible with the introduction of Galactosemia in neonatal screening programs. Electronic supplementary material The online version of this article (doi:10.1186/s12881-016-0300-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Daniel F Garcia
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil.,National Institute of Science and Technology in Stem Cell, and Cell Therapy, Regional Blood Center of Ribeirão Preto, Ribeirão Preto, SP, Brazil
| | - José S Camelo
- Department of Pediatrics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Greice A Molfetta
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil.,National Institute of Science and Technology in Stem Cell, and Cell Therapy, Regional Blood Center of Ribeirão Preto, Ribeirão Preto, SP, Brazil.,Center for Medical Genomics at Clinical Hospital of the Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Marlene Turcato
- Department of Neurology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Carolina F M Souza
- Department of Genetics, Clinical Hospital of the Porto Alegre, Porto Alegre, RS, Brazil
| | - Gilda Porta
- Department of Pediatrics, Children's Institute, Medical School of the University of São Paulo, São Paulo, SP, Brazil
| | - Carlos E Steiner
- Department of Medical Genetics, School of Medical Science, State University of Campinas, Campinas, SP, Brazil
| | - Wilson A Silva
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil. .,National Institute of Science and Technology in Stem Cell, and Cell Therapy, Regional Blood Center of Ribeirão Preto, Ribeirão Preto, SP, Brazil. .,Center for Medical Genomics at Clinical Hospital of the Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
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29
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Baskovich B, Hiraki S, Upadhyay K, Meyer P, Carmi S, Barzilai N, Darvasi A, Ozelius L, Peter I, Cho JH, Atzmon G, Clark L, Lencz T, Pe’er I, Ostrer H, Oddoux C. Expanded genetic screening panel for the Ashkenazi Jewish population. Genet Med 2016; 18:522-8. [PMID: 26334176 PMCID: PMC4814352 DOI: 10.1038/gim.2015.123] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 07/22/2015] [Indexed: 12/23/2022] Open
Abstract
PURPOSE Carrier screening programs that identify the presence of known mutations have been effective for reducing the incidence of autosomal recessive conditions in the Ashkenazi Jewish (AJ) population and other populations. Yet, these programs have not realized their full potential. Furthermore, many known autosomal recessive and dominant conditions are not screened for and the molecular basis of other conditions for which screening might be offered is unknown. METHODS Through literature review and annotation of full sequenced genomes from healthy individuals, we expanded the list of mutations. Mutations were identified in a sample of 128 fully sequenced AJ genomes that were filtered through clinical databases and curated manually for clinical validity and utility using the American College of Medical Genetics and Genomics scoring (ACMG) system. Other known mutations were identified through literature review. RESULTS A panel of 163 mutations was identified for 76 autosomal recessive, 24 autosomal dominant, and 3 X-linked disorders. CONCLUSION Screening for a broader range of disorders not only could further reduce the incidence of autosomal recessive disorders but also could offer the benefits of early or presymptomatic diagnosis.Genet Med 18 5, 522-528.
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Affiliation(s)
- Brett Baskovich
- Montefiore Medical Center, Department of Pathology, New York, NY
| | - Susan Hiraki
- Albert Einstein College of Medicine of Yeshiva University, New York, NY
| | - Kinnari Upadhyay
- Albert Einstein College of Medicine of Yeshiva University, New York, NY
| | - Philip Meyer
- Albert Einstein College of Medicine of Yeshiva University, New York, NY
| | - Shai Carmi
- Columbia University, Department of Computer Science, New York, NY
| | - Nir Barzilai
- Albert Einstein College of Medicine of Yeshiva University, New York, NY
| | - Ariel Darvasi
- Hebrew University of Jerusalem, Department of Genetics, Givat Ram, Jerusalem
| | - Laurie Ozelius
- Icahn School of Medicine at Mount Sinai School of Medicine, Department of Genetics, New York, NY
| | - Inga Peter
- Icahn School of Medicine at Mount Sinai School of Medicine, Department of Genetics, New York, NY
| | - Judy H. Cho
- Icahn School of Medicine at Mount Sinai School of Medicine, Department of Genetics, New York, NY
| | - Gil Atzmon
- Albert Einstein College of Medicine of Yeshiva University, New York, NY
- University of Haifa, Faculty of Natural Science, Israel
| | - Lorraine Clark
- Columbia University, Department of Pathology, New York, NY
| | - Todd Lencz
- Albert Einstein College of Medicine of Yeshiva University, New York, NY
| | - Itsik Pe’er
- The Feinstein Institute for Medical Research, Manhasset, NY
| | - Harry Ostrer
- Montefiore Medical Center, Department of Pathology, New York, NY
- Albert Einstein College of Medicine of Yeshiva University, New York, NY
| | - Carole Oddoux
- Montefiore Medical Center, Department of Pathology, New York, NY
- Albert Einstein College of Medicine of Yeshiva University, New York, NY
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30
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McCorvie TJ, Kopec J, Pey AL, Fitzpatrick F, Patel D, Chalk R, Shrestha L, Yue WW. Molecular basis of classic galactosemia from the structure of human galactose 1-phosphate uridylyltransferase. Hum Mol Genet 2016; 25:2234-2244. [PMID: 27005423 PMCID: PMC5081055 DOI: 10.1093/hmg/ddw091] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 03/14/2016] [Indexed: 01/22/2023] Open
Abstract
Classic galactosemia is a potentially lethal disease caused by the dysfunction of galactose 1-phosphate uridylyltransferase (GALT). Over 300 disease-associated GALT mutations have been reported, with the majority being missense changes, although a better understanding of their underlying molecular effects has been hindered by the lack of structural information for the human enzyme. Here, we present the 1.9 Å resolution crystal structure of human GALT (hGALT) ternary complex, revealing a homodimer arrangement that contains a covalent uridylylated intermediate and glucose-1-phosphate in the active site, as well as a structural zinc-binding site, per monomer. hGALT reveals significant structural differences from bacterial GALT homologues in metal ligation and dimer interactions, and therefore is a zbetter model for understanding the molecular consequences of disease mutations. Both uridylylation and zinc binding influence the stability and aggregation tendency of hGALT. This has implications for disease-associated variants where p.Gln188Arg, the most commonly detected, increases the rate of aggregation in the absence of zinc likely due to its reduced ability to form the uridylylated intermediate. As such our structure serves as a template in the future design of pharmacological chaperone therapies and opens new concepts about the roles of metal binding and activity in protein misfolding by disease-associated mutants.
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Affiliation(s)
- Thomas J McCorvie
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7DQ , UK
| | - Jolanta Kopec
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7DQ , UK
| | - Angel L Pey
- Department of Physical Chemistry, Faculty of Sciences, University of Granada, Granada E-18071, Spain
| | - Fiona Fitzpatrick
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7DQ , UK
| | - Dipali Patel
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7DQ , UK
| | - Rod Chalk
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7DQ , UK
| | - Leela Shrestha
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7DQ , UK
| | - Wyatt W Yue
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7DQ , UK
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31
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Viggiano E, Marabotti A, Burlina AP, Cazzorla C, D'Apice MR, Giordano L, Fasan I, Novelli G, Facchiano A, Burlina AB. Clinical and molecular spectra in galactosemic patients from neonatal screening in northeastern Italy: structural and functional characterization of new variations in the galactose-1-phosphate uridyltransferase (GALT) gene. Gene 2015; 559:112-8. [PMID: 25592817 DOI: 10.1016/j.gene.2015.01.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 12/29/2014] [Accepted: 01/08/2015] [Indexed: 10/24/2022]
Abstract
Classical galactosemia is an autosomal recessive inborn error of metabolism due to mutations of the GALT gene leading to toxic accumulation of galactose and derived metabolites. With the benefit of early diagnosis by neonatal screening and early therapy, the acute presentation of classical galactosemia can be prevented. However, despite early diagnosis and treatment, the long term outcome for these patients is still unpredictable because they may go on to develop cognitive disability, speech problems, neurological and/or movement disorders and, in females, ovarian dysfunction. The objectives of the current study were to report our experience with a group of galactosemic patients identified through the neonatal screening programs in northeastern Italy during the last 30years. No neonatal deaths due to galactosemia complications occurred after the introduction of the neonatal screening program. However, despite the early diagnosis and dietary treatment, the patients with classical galactosemia showed one or more long-term complications. A total of 18 different variations in the GALT gene were found in the patient cohort: 12 missense, 2 frameshift, 1 nonsense, 1 deletion, 1 silent variation, and 1 intronic. Six (p.R33P, p.G83V, p.P244S, p.L267R, p.L267V, p.E271D) were new variations. The most common variation was p.Q188R (12 alleles, 31.5%), followed by p.K285N (6 alleles, 15.7%) and p.N314D (6 alleles, 15.7%). The other variations comprised 1 or 2 alleles. In the patients carrying a new mutation, the biochemical analysis of GALT activity in erythrocytes showed an activity of <1%. In silico analysis (SIFT, PolyPhen-2 and the computational analysis on the static protein structure) showed potentially damaging effects of the six new variations on the GALT protein, thus expanding the genetic spectrum of GALT variations in Italy. The study emphasizes the difficulty in establishing a genotype-phenotype correlation in classical galactosemia and underlines the importance of molecular diagnostic testing prior to making any treatment.
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Affiliation(s)
- E Viggiano
- Division of Inborn Metabolic Diseases, Department of Paediatrics, University Hospital of Padova, Italy
| | - A Marabotti
- Department of Chemistry and Biology, University of Salerno, via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy
| | - A P Burlina
- Neurological Unit, St. Bassiano Hospital, Bassano del Grappa, Consultant in Neurometabolic Hereditary Diseases at the University Hospital of Padova, Italy
| | - C Cazzorla
- Division of Inborn Metabolic Diseases, Department of Paediatrics, University Hospital of Padova, Italy
| | - M R D'Apice
- Department of Biomedicine and Prevention, School of Medicine, University of Rome "Tor Vergata" and Fondazione PTV "Policlinico Tor Vergata", Rome, Italy
| | - L Giordano
- Division of Inborn Metabolic Diseases, Department of Paediatrics, University Hospital of Padova, Italy
| | - I Fasan
- Division of Inborn Metabolic Diseases, Department of Paediatrics, University Hospital of Padova, Italy
| | - G Novelli
- Department of Biomedicine and Prevention, School of Medicine, University of Rome "Tor Vergata" and Fondazione PTV "Policlinico Tor Vergata", Rome, Italy
| | - A Facchiano
- National Research Council, Institute of Food Science, via Roma 64, 83100 Avellino, Italy
| | - A B Burlina
- Division of Inborn Metabolic Diseases, Department of Paediatrics, University Hospital of Padova, Italy.
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32
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Ankala A, Tamhankar PM, Valencia CA, Rayam KK, Kumar MM, Hegde MR. Clinical Applications and Implications of Common and Founder Mutations in Indian Subpopulations. Hum Mutat 2014; 36:1-10. [DOI: 10.1002/humu.22704] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 09/16/2014] [Indexed: 12/19/2022]
Affiliation(s)
- Arunkanth Ankala
- Department of Human Genetics; Emory University School of Medicine; Atlanta Georgia
| | - Parag M. Tamhankar
- ICMR Genetic Research Center; National Institute for Research in Reproductive Health; Mumbai Maharashtra India
| | - C. Alexander Valencia
- Division of Human Genetics; Cincinnati Children's Hospital Medical Center; Cincinnati Ohio
- Department of Pediatrics; University of Cincinnati Medical School; Cincinnati Ohio
| | - Krishna K. Rayam
- Department of Biosciences; CMR Institute of Management Studies; Bangalore Karnataka India
| | - Manisha M. Kumar
- Department of Biosciences; CMR Institute of Management Studies; Bangalore Karnataka India
| | - Madhuri R. Hegde
- Department of Human Genetics; Emory University School of Medicine; Atlanta Georgia
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33
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Sartippour MR, Doroudian R, Frampton G, Lorey F, Helmer G, Ho T, Bhandal A. Identification of galactose-1-phosphate uridyl transferase gene common mutations in dried blood spots. Clin Chim Acta 2014; 436:298-302. [DOI: 10.1016/j.cca.2014.06.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 06/07/2014] [Accepted: 06/16/2014] [Indexed: 10/25/2022]
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Choi R, Jo KI, Ko DH, Lee DH, Song J, Jin DK, Ki CS, Lee SY, Kim JW, Lee YW, Park HD. Novel GALT variations and mutation spectrum in the Korean population with decreased galactose-1-phosphate uridyltransferase activity. BMC MEDICAL GENETICS 2014; 15:94. [PMID: 25124065 PMCID: PMC4236512 DOI: 10.1186/s12881-014-0094-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 08/04/2014] [Indexed: 11/10/2022]
Abstract
BACKGROUND Classic galactosemia (OMIM #230400) is an autosomal recessive metabolic disorder caused by a deficiency of the galactose-1-phosphate uridyltransferase (GALT, EC2.7.7.12) protein due to mutations in the GALT gene. The aim of this study was to provide a comprehensive and updated mutation spectrum of GALT in a Korean population. METHODS Thirteen unrelated patients screened positive for galactosemia in a newborn screening program were included in this study. They showed a reduced GALT enzyme activity in red blood cells. Direct sequencing of the GALT gene and in silico analyses were done to evaluate the impact of novel variations upon GALT enzyme activity. We also reviewed previous reports for GALT mutations in Koreans. RESULTS We identified six novel likely pathogenic variations including three missense (p.Ala101Asp, p.Tyr165His, and p.Pro257Thr), one small deletion/insertion [c.826_827delinsAA (p.Ala276Asn)], one frameshift (p.Asn96Serfs*5), and one splicing (c.378-1G > C) likely pathogenic variations. The most frequent variation was the Duarte variant (c.940A > G, 35.3%), followed by c.507G > C (p.Gln169His, 9.6%), among 34 Korean patients. Other mutations were widely scattered. None of the eight common mutations used for targeted mutation analysis in Western countries including p.Gln188Arg, p.Ser135Leu, p.Lys285Asn, p.Leu195Pro, p.Tyr209Cys, p.Phe171Ser, c.253-2A > G, and a 5 kb deletion, had been found in Koreans until this study. CONCLUSIONS Considering the mutation spectrum in Koreans, direct sequence analysis of entire GALT exons is recommended for accurate diagnosis. The mutations responsible for GALT deficiency in the Korean population were clearly different from those of other populations.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Yong-Wha Lee
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 135-710, Republic of Korea.
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Functional correction by antisense therapy of a splicing mutation in the GALT gene. Eur J Hum Genet 2014; 23:500-6. [PMID: 25052314 DOI: 10.1038/ejhg.2014.149] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Revised: 06/24/2014] [Accepted: 06/28/2014] [Indexed: 12/24/2022] Open
Abstract
In recent years, antisense therapy has emerged as an increasingly important therapeutic approach to tackle several genetic disorders, including inborn errors of metabolism. Intronic mutations activating cryptic splice sites are particularly amenable to antisense therapy, as the canonical splice sites remain intact, thus retaining the potential for restoring constitutive splicing. Mutational analysis of Portuguese galactosemic patients revealed the intronic variation c.820+13A>G as the second most prevalent mutation, strongly suggesting its pathogenicity. The aim of this study was to functionally characterize this intronic variation, to elucidate its pathogenic molecular mechanism(s) and, ultimately, to correct it by antisense therapy. Minigene splicing assays in two distinct cell lines and patients' transcript analyses showed that the mutation activates a cryptic donor splice site, inducing an aberrant splicing of the GALT pre-mRNA, which in turn leads to a frameshift with inclusion of a premature stop codon (p.D274Gfs*17). Functional-structural studies of the recombinant wild-type and truncated GALT showed that the latter is devoid of enzymatic activity and prone to aggregation. Finally, two locked nucleic acid oligonucleotides, designed to specifically recognize the mutation, successfully restored the constitutive splicing, thus establishing a proof of concept for the application of antisense therapy as an alternative strategy for the clearly insufficient dietary treatment in classic galactosemia.
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Coelho AI, Trabuco M, Ramos R, Silva MJ, Tavares de Almeida I, Leandro P, Rivera I, Vicente JB. Functional and structural impact of the most prevalent missense mutations in classic galactosemia. Mol Genet Genomic Med 2014; 2:484-96. [PMID: 25614870 PMCID: PMC4303218 DOI: 10.1002/mgg3.94] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 05/20/2014] [Accepted: 05/22/2014] [Indexed: 11/10/2022] Open
Abstract
Galactose-1-phosphate uridylyltransferase (GALT) is a key enzyme in galactose metabolism, particularly important in the neonatal period due to ingestion of galactose-containing milk. GALT deficiency results in the genetic disorder classic galactosemia, whose pathophysiology is still not fully elucidated. Whereas classic galactosemia has been hypothesized to result from GALT misfolding, a thorough functional-structural characterization of GALT most prevalent variants was still lacking, hampering the development of alternative therapeutic approaches. The aim of this study was to investigate the structural-functional effects of nine GALT mutations, four of which account for the vast majority of the mutations identified in galactosemic patients. Several methodologies were employed to evaluate the mutations' impact on GALT function, on the protein secondary and tertiary structures, and on the aggregation propensity. The major structural effect concerns disturbed propensity for aggregation, particularly striking for the p.Q188R variant, resulting from the most frequent (∼60%) allele at a worldwide scale. The absence of major effects at the secondary and tertiary structure levels suggests that the disturbed aggregation results from subtle perturbations causing a higher and/or longer exposure of hydrophobic residues in the variants as compared to WT GALT. The results herein described indicate a possible benefit from introducing proteostasis regulators and/or chemical/pharmacological chaperones to prevent the accumulation of protein aggregates, in new avenues of therapeutic research for classic galactosemia.
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Affiliation(s)
- Ana I Coelho
- Metabolism and Genetics Group, Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon 1649-003, Lisbon, Portugal
| | - Matilde Trabuco
- Metabolism and Genetics Group, Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon 1649-003, Lisbon, Portugal
| | - Ruben Ramos
- Metabolism and Genetics Group, Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon 1649-003, Lisbon, Portugal
| | - Maria João Silva
- Metabolism and Genetics Group, Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon 1649-003, Lisbon, Portugal ; Department of Biochemistry and Human Biology, Faculty of Pharmacy, University of Lisbon 1649-003, Lisbon, Portugal
| | - Isabel Tavares de Almeida
- Metabolism and Genetics Group, Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon 1649-003, Lisbon, Portugal ; Department of Biochemistry and Human Biology, Faculty of Pharmacy, University of Lisbon 1649-003, Lisbon, Portugal
| | - Paula Leandro
- Metabolism and Genetics Group, Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon 1649-003, Lisbon, Portugal ; Department of Biochemistry and Human Biology, Faculty of Pharmacy, University of Lisbon 1649-003, Lisbon, Portugal
| | - Isabel Rivera
- Metabolism and Genetics Group, Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon 1649-003, Lisbon, Portugal ; Department of Biochemistry and Human Biology, Faculty of Pharmacy, University of Lisbon 1649-003, Lisbon, Portugal
| | - João B Vicente
- Metabolism and Genetics Group, Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon 1649-003, Lisbon, Portugal ; Department of Biochemistry and Human Biology, Faculty of Pharmacy, University of Lisbon 1649-003, Lisbon, Portugal
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Subfertility and growth restriction in a new galactose-1 phosphate uridylyltransferase (GALT) - deficient mouse model. Eur J Hum Genet 2014; 22:1172-9. [PMID: 24549051 DOI: 10.1038/ejhg.2014.12] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 01/03/2014] [Accepted: 01/15/2014] [Indexed: 12/27/2022] Open
Abstract
The first GalT gene knockout (KO) mouse model for Classic Galactosemia (OMIM 230400) accumulated some galactose and its metabolites upon galactose challenge, but was seemingly fertile and symptom free. Here we constructed a new GalT gene-trapped mouse model by injecting GalT gene-trapped mouse embryonic stem cells into blastocysts, which were later implanted into pseudo-pregnant females. High percentage GalT gene-trapped chimera obtained were used to generate heterozygous and subsequently, homozygous GalT gene-trapped mice. Biochemical assays confirmed total absence of galactose-1 phosphate uridylyltransferase (GALT) activity in the homozygotes. Although the homozygous GalT gene-trapped females could conceive and give birth when fed with normal chow, they had smaller litter size (P=0.02) and longer time-to-pregnancy (P=0.013) than their wild-type littermates. Follicle-stimulating hormone levels of the mutant female mice were not significantly different from the age-matched, wild-type females, but histological examination of the ovaries revealed fewer follicles in the homozygous mutants (P=0.007). Administration of a high-galactose (40% w/w) diet to lactating homozygous GalT gene-trapped females led to lethality in over 70% of the homozygous GalT gene-trapped pups before weaning. Cerebral edema, abnormal changes in the Purkinje and the outer granular cell layers of the cerebellum, as well as lower blood GSH/GSSG ratio were identified in the galactose-intoxicated pups. Finally, reduced growth was observed in GalT gene-trapped pups fed with normal chow and all pups fed with high-galactose (20% w/w) diet. This new mouse model presents several of the complications of Classic Galactosemia and will be useful to investigate pathogenesis and new therapies.
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Coelho AI, Ramos R, Gaspar A, Costa C, Oliveira A, Diogo L, Garcia P, Paiva S, Martins E, Teles EL, Rodrigues E, Cardoso MT, Ferreira E, Sequeira S, Leite M, Silva MJ, de Almeida IT, Vicente JB, Rivera I. A frequent splicing mutation and novel missense mutations color the updated mutational spectrum of classic galactosemia in Portugal. J Inherit Metab Dis 2014; 37:43-52. [PMID: 23749220 DOI: 10.1007/s10545-013-9623-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 05/16/2013] [Accepted: 05/17/2013] [Indexed: 01/28/2023]
Abstract
Classic galactosemia is an autosomal recessive disorder caused by deficient galactose-1-phosphate uridylyltransferase (GALT) activity. Patients develop symptoms in the neonatal period, which can be ameliorated by dietary restriction of galactose. Many patients develop long-term complications, with a broad range of clinical symptoms whose pathophysiology is poorly understood. The high allelic heterogeneity of GALT gene that characterizes this disorder is thought to play a determinant role in biochemical and clinical phenotypes. We aimed to characterize the mutational spectrum of GALT deficiency in Portugal and to assess potential genotype-phenotype correlations. Direct sequencing of the GALT gene and in silico analyses were employed to evaluate the impact of uncharacterized mutations upon GALT functionality. Molecular characterization of 42 galactosemic Portuguese patients revealed a mutational spectrum comprising 14 nucleotide substitutions: ten missense, two nonsense and two putative splicing mutations. Sixteen different genotypic combinations were detected, half of the patients being p.Q188R homozygotes. Notably, the second most frequent variation is a splicing mutation. In silico predictions complemented by a close-up on the mutations in the protein structure suggest that uncharacterized missense mutations have cumulative point effects on protein stability, oligomeric state, or substrate binding. One splicing mutation is predicted to cause an alternative splicing event. This study reinforces the difficulty in establishing a genotype-phenotype correlation in classic galactosemia, a monogenic disease whose complex pathogenesis and clinical features emphasize the need to expand the knowledge on this "cloudy" disorder.
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Affiliation(s)
- Ana I Coelho
- Metabolism & Genetics Group, Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon, Av. Prof. Gama Pinto, 1643-009, Lisbon, Portugal
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Tran TTV, Liu Y, Zwick ME, Ramachandran D, Cutler DJ, Huang X, Berry GT, Fridovich-Keil JL. A De Novo Variant in Galactose-1-P Uridylyltransferase (GALT) Leading to Classic Galactosemia. JIMD Rep 2014; 19:1-6. [DOI: 10.1007/8904_2014_349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Revised: 07/27/2014] [Accepted: 07/31/2014] [Indexed: 11/28/2022] Open
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Papachristoforou R, Petrou PP, Sawyer H, Williams M, Drousiotou A. A Novel Large Deletion Encompassing the Whole of the Galactose-1-Phosphate Uridyltransferase (GALT) Gene and Extending into the Adjacent Interleukin 11 Receptor Alpha (IL11RA) Gene Causes Classic Galactosemia Associated with Additional Phenotypic Abnormalities. JIMD Rep 2013; 12:91-8. [PMID: 24002815 DOI: 10.1007/8904_2013_249] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 06/10/2013] [Accepted: 06/24/2013] [Indexed: 12/12/2022] Open
Abstract
Objective The characterization of a novel large deletion in the galactose-1-phosphate uridyltransferase (GALT) gene accounting for the majority of disease alleles in Cypriot patients with classic galactosemia. Methods DNA sequencing was used to identify the mutations followed by multiplex ligation-dependent probe amplification (MLPA) analysis in the cases suspected of harboring a deletion. In order to map the breakpoints of the novel deletion, a PCR walking approach was employed. A simple PCR assay was validated for diagnostic testing for the new deletion. Haplotype analysis was performed using microsatellite markers in the chromosomal region 9p. RT-PCR was used to study RNA expression in lymphoblastoid cell lines. Results The new deletion spans a region of 8489 bp and eliminates all GALT exons as well as the non-translated sequences of the adjacent interleukin 11 receptor alpha (IL11RA) gene. In addition, the deletion is flanked by a 6 bp block of homologous sequence on either side suggesting that a single deletion event has occurred, probably mediated by a recombination mechanism. Microsatellite marker analysis revealed the existence of a common haplotype. The RNA expression studies showed a lack of IL11RA transcripts in patients homozygous for the deletion. Conclusions We have identified and characterized a novel contiguous deletion which affects both the GALT enzyme and the IL11RA protein resulting in classic galactosemia with additional phenotypic abnormalities such as craniosynostosis, a feature that has been associated with defects in the IL11RA gene.
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Affiliation(s)
- Rena Papachristoforou
- Department of Biochemical Genetics, The Cyprus Institute of Neurology and Genetics, 23462, 1683, Nicosia, Cyprus
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Galactosemia in the Turkish population with a high frequency of Q188R mutation and distribution of Duarte-1 and Duarte-2 variations. J Hum Genet 2013; 58:675-8. [DOI: 10.1038/jhg.2013.76] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 06/04/2013] [Accepted: 07/01/2013] [Indexed: 11/08/2022]
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Singh R, Thapa BR, Kaur G, Prasad R. Biochemical and molecular characterization of GALT gene from Indian galactosemia patients: Identification of 10 novel mutations and their structural and functional implications. Clin Chim Acta 2012; 414:191-6. [DOI: 10.1016/j.cca.2012.09.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2012] [Accepted: 09/09/2012] [Indexed: 11/28/2022]
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Mahmood U, Imran M, Naik SI, Cheema HA, Saeed A, Arshad M, Mahmood S. Detection of common mutations in the GALT gene through ARMS. Gene 2012; 509:291-4. [DOI: 10.1016/j.gene.2012.08.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 08/03/2012] [Accepted: 08/03/2012] [Indexed: 11/24/2022]
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Boutron A, Marabotti A, Facchiano A, Cheillan D, Zater M, Oliveira C, Costa C, Labrune P, Brivet M. Mutation spectrum in the French cohort of galactosemic patients and structural simulation of 27 novel missense variations. Mol Genet Metab 2012; 107:438-47. [PMID: 22944367 DOI: 10.1016/j.ymgme.2012.07.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 07/31/2012] [Accepted: 07/31/2012] [Indexed: 11/20/2022]
Abstract
BACKGROUND Classic galactosemia refers to galactose-1-phosphate uridyltransferase (GALT) deficiency and is characterized by long-term complications of unknown mechanism and high allelic heterogeneity of GALT gene. AIM To report molecular characterization of GALT variations in 210 French families, to analyze the structural effects of novel missense variations and to assess informativity of structural data in predicting outcome. METHODS Sequencing of exons and intron-exon junctions of GALT gene was completed in unsolved cases by analysis of a long range PCR product. Structural consequences of novel missense variations were predicted using a homology model of GALT protein and a semi-automated analysis which integrates simulation of variations, structural analyses and two web servers dedicated to identify mutation-induced change of protein stability. RESULTS Forty four novel variations were identified, among them 27 nucleotide substitutions. In silico modeling of these missense variations showed that 12 variations are predicted to impair subunit interactions and/or active site conformation and that 23 variations modify H-bond or salt-bridge networks. Twenty variations decrease the global stability of the protein. Five variations had apparently no structural effect. CONCLUSION Our results expand the mutation spectrum in GALT gene and the list of GALT variations analyzed at the structural level, providing new data to assess the pathophysiology of galactosemia.
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Affiliation(s)
- Audrey Boutron
- Biochimie - Hôpital de Bicêtre, Hôpitaux Universitaires Paris-Sud, APHP-Paris, France.
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Frequency distribution of Q188R, N314D, Duarte 1, and Duarte 2 GALT variant alleles in an Indian galactosemia population. Biochem Genet 2012; 50:871-80. [PMID: 22798028 DOI: 10.1007/s10528-012-9527-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2011] [Accepted: 06/20/2012] [Indexed: 10/28/2022]
Abstract
Classical galactosemia is a genetic disorder caused by mutations in the galactose-1-phosphate uridyltransferase (GALT) gene. The Q188R and N314D mutations are the most frequently cited GALT gene mutations. N314D is further associated with two variants, Duarte 1 and Duarte 2. Nevertheless, no reports are available on the clinical and molecular spectrum of galactosemia from the Indian population. The present study was designed to establish the frequency of these two most common mutations and their variants in Indian galactosemia patients so as to determine a single most common mutation/polymorphism for establishing the DNA-based diagnosis of galactosemia. Three alleles were found to be present at a frequency of 0.036 (Q188R), 0.40 (N314D), and 0.39 (D2); no D1 alleles were found. A significantly higher frequency of the Duarte 2 allele in our population suggests the presence of a milder form of galactosemia, which can be well managed by early diagnosis and dietary management.
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Berry GT. Galactosemia: when is it a newborn screening emergency? Mol Genet Metab 2012; 106:7-11. [PMID: 22483615 DOI: 10.1016/j.ymgme.2012.03.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 03/14/2012] [Accepted: 03/14/2012] [Indexed: 10/28/2022]
Abstract
Classic galactosemia is an autosomal recessive disorder of carbohydrate metabolism, due to a severe deficiency of the enzyme, galactose-1-phosphate uridyltransferase (GALT), that catalyzes the conversion of galactose-1-phosphate and uridine diphosphate glucose (UDPglucose) to uridine diphosphate galactose (UDPgalactose) and glucose-1-phosphate. Upon consumption of lactose in the neonatal period, the affected infants develop a potentially lethal disease process with multiorgan involvement. Since the advent of newborn screening (NBS) for galactosemia, we rarely encounter such overwhelmingly ill newborns. After ascertainment that the positive NBS indicates the possibility of galactosemia due to GALT deficiency, the critical question for the physician is whether the infant has the classic or a variant form of GALT deficiency, as classic galactosemia is a medical emergency. However, there are over 230 GALT gene mutations that have been detected around the world. Yet, most positive NBS tests are due to the Duarte biochemical variant condition or a simple false positive. In order to make the correct decision as well as provide informative counseling to parents of infants with a positive NBS, I utilize a relatively simple classification scheme for GALT deficiency. There are three basic forms of GALT deficiency: 1) classic galactosemia; 2) clinical variant galactosemia; and 3) biochemical variant galactosemia. The classic genotype is typified by Q188R/Q188R, the clinical variant by S135L/S135L and the biochemical variant by N314D/Q188R. In classic galactosemia, the erythrocyte GALT enzyme activity is absent or markedly reduced, the blood galactose and erythrocyte galactose-1-phosphate levels are markedly elevated, and the patient is at risk to develop potentially lethal E. coli sepsis, as well as the long-term diet-independent complications of galactosemia. Patients with the clinical variant form require treatment but do not die from E. coli sepsis in the neonatal period. If the clinician suspects galactosemia, even if based on clinical findings alone, then the infant should be immediately placed on a lactose-restricted diet. The purpose of this review is to help the clinician make the correct therapeutic decision after an NBS test has returned positive for galactosemia.
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Affiliation(s)
- Gerard T Berry
- The Manton Center for Orphan Disease Research, Division of Genetics, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA.
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Abstract
Galactosemia is a secondary glycosylation disorder characterized by galactose deficiency of glycoproteins and glycolipids. Abnormal glycosylation of coagulation factors and evidence of liver disease are associated with coagulopathy in galactosemic infants. We report a case of a neonate with galactosemia presenting with bilateral vitreous hemorrhage (VH). During the follow-up, hemorrhage in the right eye resolved; however, it persisted in the left eye. Vitrectomy was planned for the left eye. In addition to cataract, VH is another ophthalmic finding in galactosemia with serious sequelae such as amblyopia. Serious complications of coagulopathy in galactosemic infants can be prevented with early diagnosis and prompt treatment. Inclusion of galactosemia in the neonatal screening program offers an opportunity to prevent early severe symptoms.
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McCorvie TJ, Timson DJ. Structural and molecular biology of type I galactosemia: disease-associated mutations. IUBMB Life 2011; 63:949-54. [PMID: 21960482 DOI: 10.1002/iub.510] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 05/06/2011] [Indexed: 11/06/2022]
Abstract
Type I galactosemia results from reduced galactose 1-phosphate uridylyltransferase (GALT) activity. Signs of disease include damage to the eyes, brain, liver, and ovaries. However, the exact nature and severity of the pathology depends on the mutation(s) in the patient's genes and his/her environment. Considerable enzymological and structural knowledge has been accumulated and this provides a basis to explain, at a biochemical level, impairment in the enzyme in the more than 230 disease-associated variants, which have been described. The most common variant, Q188R, occurs close to the active site and the dimer interface. The substitution probably disrupts both UDP-sugar binding and homodimer stability. Other alterations, for example K285N, occur close to the surface of the enzyme and most likely affect the folding and stability of the enzyme. There are a number of unanswered questions in the field, which require resolution. These include the possibility that the main enzymes of galactose metabolism form a supramolecular complex and the need for a high resolution crystal structure of human GALT.
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Affiliation(s)
- Thomas J McCorvie
- School of Biological Sciences, Queen's University Belfast, Medical Biology Centre, Belfast, Northern Ireland, UK
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Krabbi K, Uudelepp ML, Joost K, Zordania R, Õunap K. Long-term complications in Estonian galactosemia patients with a less strict lactose-free diet and metabolic control. Mol Genet Metab 2011; 103:249-53. [PMID: 21501963 DOI: 10.1016/j.ymgme.2011.03.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 03/29/2011] [Indexed: 11/29/2022]
Abstract
The main aim of our study was to retrospectively evaluate long-term complications and measure urinary galactose and galactitol excretion in classical galactosemia patients in Estonia who have been treated with a less restricted lactose-free diet and metabolic control. Our study group consisted of five classical galactosemia patients aged 7-14 years and diagnosed since 1996 in Estonia. Their diet eliminates lactose present in dairy foods, but we did not restrict the consumption of mature cheeses, fruits and vegetables. All patients had normal growth, except for one patient who was overweight at the last evaluation. In three patients mental and speech development was normal. One patient, number 1, who was diagnosed latest (at 6 weeks of age), had moderate mental retardation, verbal dyspraxia, extrapyramidal signs and bilateral cataracts. In both patients with developmental problems, a brain MRI showed bilateral subcortical changes in the cerebral white matter. Of four females, only patient 4 (p.Q188R homozygote) has premature ovarian insufficiency. Urinary galactose and galactitol content were retrospectively measured using high-performance liquid chromatography and refractive-index detection from urinary samples that were preserved during the years 1996-2009. Galactose ranged from 60 to 600 mmol/mol creatinine (normal=4-6), and galactitol ranged from 70 to 1200 mmol/mol creatinine (normal=2-4), which was 10-100 and 17-300 times higher than the respective reference ranges for galactose and galactitol. We conclude that a less strict lactose-free diet and metabolic control performed in Estonian classical galactosemia patients does not change long-term outcome compared to previously published studies.
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Affiliation(s)
- K Krabbi
- Institute of Chemistry, Faculty of Sciences, Tallinn University of Technology, Tallinn, Estonia.
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