Exclusive gene mapping of congenital microphthalmia in a Chinese family

Congenital microphthalmia is a developmental ocular disorder and might be caused by the mutations in the genes involved in eye development. To uncover the genetic cause in a six-generation Chinese pedigree with autosomal dominant congenital microphthalmia, we performed genescan and linkage analysis in this family. Fourteen microsatellite markers on chromosomes 3, 11, 14 and 15 were selected as genetic markers according to the five previously reported loci associated with microphthalmia (MITF, SOX2, PAX6, MCOP and NNO2). The genomic DNA of each member in the pedigree was amplified with 14 pairs of fluorescence labeled primers. Genome screening and genotyping were conducted on ABI377 DNA sequencer and linkage analysis was performed with Linkage software package. All two-point LOD scores of linkage analysis between the suggested disease genes and microsatellite markers were <−2, which indicated that none of the five genes were responsible for microphthalmia in this Chinese family. Microphthalmia in this family may be caused by mutation in a new gene which is essential in eye development.