Dataset Information

Clinical profile and molecular characterization of Galactosemia in Brazil: identification of seven novel mutations.

ABSTRACT: 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.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.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.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.

SUBMITTER: Garcia DF

PROVIDER: S-EPMC4866286 | biostudies-literature | 2016 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Clinical profile and molecular characterization of Galactosemia in Brazil: identification of seven novel mutations.

Garcia Daniel F DF Camelo José S JS Molfetta Greice A GA Turcato Marlene M Souza Carolina F M CF Porta Gilda G Steiner Carlos E CE Silva Wilson A WA

BMC medical genetics 20160512 1

<h4>Background</h4>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 hundred ...[more]

PMID: 27176039

Similar Datasets

Project description:BACKGROUND: Classic Ehlers-Danlos syndrome (cEDS) is a rare autosomal dominant connective tissue disorder that is primarily characterized by skin hyperextensibility, abnormal wound healing/atrophic scars, and joint hypermobility. A recent study demonstrated that more than 90% of patients who satisfy all of these major criteria harbor a type V collagen (COLLV) defect. METHODS: This cohort included 40 patients with cEDS who were clinically diagnosed according to the Villefranche nosology. The flowchart that was adopted for mutation detection consisted of sequencing the COL5A1 gene and, if no mutation was detected, COL5A2 analysis. In the negative patients the presence of large genomic rearrangements in COL5A1 was investigated using MLPA, and positive results were confirmed via SNP-array analysis. RESULTS: We report the clinical and molecular characterization of 40 patients from 28 families, consisting of 14 pediatric patients and 26 adults. A family history of cEDS was present in 9 patients. The majority of the patients fulfilled all the major diagnostic criteria for cEDS; atrophic scars were absent in 2 females, skin hyperextensibility was not detected in a male and joint hypermobility was negative in 8 patients (20% of the entire cohort). Wide inter- and intra-familial phenotypic heterogeneity was observed. We identified causal mutations with a detection rate of approximately 93%. In 25/28 probands, COL5A1 or COL5A2 mutations were detected. Twenty-one mutations were in the COL5A1 gene, 18 of which were novel (2 recurrent). Of these, 16 mutations led to nonsense-mediated mRNA decay (NMD) and to COLLV haploinsufficiency and 5 mutations were structural. Two novel COL5A2 splice mutations were detected in patients with the most severe phenotypes. The known p. (Arg312Cys) mutation in the COL1A1 gene was identified in one patient with vascular-like cEDS. CONCLUSIONS: Our findings highlight that the three major criteria for cEDS are useful and sufficient for cEDS clinical diagnosis in the large majority of the patients. The borderline patients for whom these criteria fail can be diagnosed when minor signs of connective tissue diseases and family history are present and when genetic testing reveals a defect in COLLV. Our data also confirm that COL5A1 and COL5A2 are the major, if not the only, genes involved in cEDS.

Project description:To test for the potential presence of novel mutations in the zinc finger protein (ZNF469) gene in patients with sporadic keratoconus (KC) from a Han Chinese population.Fifty-three patients with primary KC, 30 patients with high myopia (HM), and 100 unrelated population-matched healthy controls without any ocular or systemic disorders, all of Han Chinese ethnicity, were recruited. Blood samples were donated, and genomic DNA was isolated from peripheral blood leukocytes. Sequence variations in ZNF469 were initially identified in patients with KC with next-generation sequencing and subsequently confirmed using Sanger sequencing. Sequence variants identified in patients with KC were subsequently screened in 30 patients with HM and 100 healthy control subjects. Other genes that were reported to be related to KC were also screened in the patients with KC who carried the mutations in ZNF469. The Sorting Intolerant Form Tolerant (SIFT) program was used to predict the effect of amino acid substitution on the ZNF469 protein.Sixteen sequence variants in the coding regions of ZNF469 were identified in this Chinese KC cohort. After five known single nucleotide polymorphisms (SNPs), one false-positive result, and three mutations that were also detected in the results of the whole-exome sequencing (WES) data performed in 220 Han Chinese individuals without ocular abnormalities were removed, seven novel mutations in ZNF469 (c.2059G>A, c.2137C>A, c.3466G>A, c.3749C>T, c.4300G>A, c.4684G>A, and c.7262G>A) that were predicted to be potentially damaging were identified. The patient with KC with the c.3466G>A mutation was also shown to carry one dedicator of cytokinesis 9 (DOCK9) mutation (c.1940C>T). None of the mutations were detected in the patients with HM or the healthy controls. All of the seven mutations in the patients with KC were heterozygote.The results suggested for the first time that ZNF469 has a pathogenic role in Chinese patients with KC and have widened the mutation spectrum of KC in the Han Chinese population.

Dataset Information

Clinical profile and molecular characterization of Galactosemia in Brazil: identification of seven novel mutations.

Publications

Clinical profile and molecular characterization of Galactosemia in Brazil: identification of seven novel mutations.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure