Evaluation of the ELOVL4 gene in a Chinese family with autosomal dominant STGD3-like macular dystrophy.

Stargardt disease-3 (STGD3) is an autosomal dominant juvenile-onset macular dystrophy characterized by progressive decreasing visual acuity, bilateral atrophic changes in the macula and absence of characteristic dark choroids. We identified a STGD3-like macular dystrophy pedigree by clinical examination. To explore whether the STGD3-like phenotype in the kindred is linked to ELOVL4 gene or associated with any other identified STGD gene, we extracted genomic DNA from leukocytes of peripheral blood from the available family members and 50 normal controls for mutation analysis. Then the exons of ELOVL4, RDS and the three exons of ABCR were amplified by polymerase chain reaction (PCR). All PCR products were screened for mutations by combination of denaturing high-performance liquid chromatography (DHPLC) analysis and DNA sequencing. No mutation was found in the exons of three candidate genes, but we obtained three non-pathogenic polymorphisms, IVS5-2533T-->A in ELOVL4, 558C-->T (Val106Val) and 1150G-->C (Glu304Gln) in RDS. And IVS5-2533T-->A is never shown in the previous references. These data suggested that there exist other unknown genes responsible for the STGD3-like phenotype in the pedigree.