Identification of two novel mutations in families with X-linked ocular albinism.
نویسندگان
چکیده
PURPOSE Our goal was to evaluate the OA1 gene, also known as G-protein coupled receptor 143 (GPR143), in two United States families, one from the mid-west and one from the mid-south, who had clinical features of X-linked ocular albinism. Both families had previously tested negative for mutations. METHODS Selected family members underwent a detailed ophthalmologic evaluation. Blood samples were obtained, and genomic DNA isolated. Mutational analysis by direct sequencing was used to evaluate OA1 exons and intron/exon junction. RESULTS Ophthalmic features in the evaluated family members were consistent with X-linked ocular albinism. Mutation screening and sequence analysis of the OA1 gene in the mid-west family identified a novel 190delC deletion. The 190delC mutation was predicted to result in a frameshift following Ser63, an addition of 16 novel amino acids and a premature stop. In the mid-south family, a 346T>G substitution was identified in exon 2. The 346T>G mutation was predicted to result in a substitution of the highly conserved Cys116 to Gly and disruption of the disulfide bridge essential for the normal structure and function of the OA1 protein. CONCLUSIONS Two novel mutations in the OA1 gene were identified in two families with ocular albinism. The identified mutations are likely loss-of-function mutations. These findings confirm that mutations in the OA1 gene are associated with the majority of X-linked ocular albinism cases.
منابع مشابه
Molecular genetic and clinical evaluation of three Chinese families with X-linked ocular albinism
X-linked ocular albinism (OA1) is an X-linked inherited disease characterized by hypopigmentation of the fundus and nystagmus. Our study performed mutation analysis of the G protein-coupled receptor 143 gene (GPR143) and assessed the clinical characteristics of OA1 in three Chinese families. Three novel mutations, c.333_360+14del42insCTT, c.276G>A (p.W92X), and c.793C>T (p.R265X), were identifi...
متن کاملGPR143 Gene Mutations in Five Chinese Families with X-linked Congenital Nystagmus
The ocular albinism type I (OA1) is clinically characterized by impaired visual acuity, nystagmus, iris hypopigmentation with translucency, albinotic fundus, and macular hypoplasia together with normally pigmented skin and hair. However, it is easily misdiagnosed as congenital idiopathic nystagmus in some Chinese patients with OA1 caused by the G-protein coupled receptor 143 (GPR143) gene mutat...
متن کاملNovel GPR143 mutations and clinical characteristics in six Chinese families with X-linked ocular albinism
PURPOSE There are few genetic studies and clinical descriptions of Asian patients with X-linked ocular albinism (OA1). In the present study, the mutation analysis of G protein-coupled receptor 143 gene (GPR143) and clinical characteristics were assessed in Chinese patients with OA1. METHODS Six families with OA1 were recruited from our pediatric and genetic eye clinic. Genomic DNA was prepare...
متن کاملSCIENTIFIC REPORT Abnormal crossing of the optic fibres shown by evoked magnetic fields in patients with ocular albinism with a novel mutation in the OA1 gene
Aim: To perform genealogical and clinical studies in Finnish families with X linked ocular albinism (OA1), including characterisation of the potential misrouting of optic fibres by evaluating visual evoked magnetic fields (VEFs), and to determine the mutation behind the disease. Methods: Three families with OA1 were clinically examined. VEFs were measured in two affected males and in one female...
متن کاملAbnormal crossing of the optic fibres shown by evoked magnetic fields in patients with ocular albinism with a novel mutation in the OA1 gene.
AIM To perform genealogical and clinical studies in Finnish families with X linked ocular albinism (OA1), including characterisation of the potential misrouting of optic fibres by evaluating visual evoked magnetic fields (VEFs), and to determine the mutation behind the disease. METHODS Three families with OA1 were clinically examined. VEFs were measured in two affected males and in one female...
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عنوان ژورنال:
- Molecular vision
دوره 13 شماره
صفحات -
تاریخ انتشار 2007