Gene Mutation Pattern In A Chinese Family With Stargardt3-like Disease

Stargardt disease-3 (STGD3) is an autosomal dominant juvenile-onset maculardystrophy characterized by progressive decreasing visual acuity, bilateral atrophic changesin the macula and absence of characteristic dark choroids. By clinical examination, such ascorrected visual acuity, color fundus photography, electroretinogram (ERG) and FFA, weidentified a STGD3-like macular dystrophy pedigree from Ningbo, Zhejiang Province,China, including 10 affected and 24 unaffected individuals.To explore whether the STGD3-like phenotype in the kindred is linked to ELOVL4gene or associated with any other identified STGD gene, we extracted genomic DNA fromleukocytes of peripheral blood from the available family members and 50 normal controls,then the exons of ELOVL4, RDS and ABCR were amplified by polymerase chain reaction(PCR). All PCR products were screened for mutations by combination of denaturinghigh-performance liquid chromatography (DHPLC) analysis and DNA sequencing. Nomutation was found in the exons of three candidate genes, but only three non-pathogenicpolymorphisms, IVS5-T2533A in ELOVL4 gene, C558T (Val106Val) and G1150C(Glu304Gln) in RDS gene. And IVS5-T2533A is never shown in the previous references.These data suggested that there exist other unknown susceptible genes responsible forthe STGD3-like phenotype in this pedigree. Identification of the pathogenic gene in thepedigree might give important insights into the pathogenesis of hereditary maculardystrophies, providing the molecular basis of classification, molecular diagnosis, prenataldiagnosis and being helpful for the discovery of new drug and gene therapy of STGDdisease.