A Novel Missense Mutation in Causes Congenital Disorder of Glycosylation Type I (Cerebello-Ocular Syndrome)

Autor: Yasser Al-Sarraj BSC, Tawfeg Ben-Omran MD, Mohammed Tolefat MBBS, Yosra Bejaoui MSc, Hatem El-Shanti MD, Marios Kambouris PhD
Jazyk: angličtina
Rok vydání: 2014
Předmět:
Zdroj: Journal of Inborn Errors of Metabolism and Screening, Vol 2 (2014)
Druh dokumentu: article
ISSN: 2326-4594
23264098
DOI: 10.1177/2326409814550528
Popis: A consanguineous Qatari family having an autosomal recessive disorder characterized by severe mental retardation, cerebellar vermis hypoplasia, retinal degeneration, optic nerve atrophy, ataxic gait, and seizures was studied for identification of the offending gene and mutation. Homozygosity mapping identified an 11.4 Mb critical interval at 4q12 to q13.2 that would contain the gene responsible for the disorder. Ten positional candidate genes were screened for pathogenic mutations, but none were identified. Next-generation exome sequencing in one affected individual identified a novel SRD5A3 missense mutation c.T744G/p.F248L, which was subsequently confirmed by Sanger sequencing, suggesting a congenital disorder of glycosylation type IQ defect. Isoelectric focusing of serum transferrin showed a type I pattern indicative of an N -glycan assembly defect. This is a novel pathogenic mutation and the first SRD5A3 missense mutation as all others are protein-truncating mutations.
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