R954 mutations in KIF21A gene in Chinese patients with congenital fibrosis of extraocular muscles

Abstract

Screening KIF21A gene mutation in 9 families with congenital fibrosis of extraocular muscles and 7 sporadic cases. Families were ascertained and patients underwent complete ophthalmological examinations. The probands of 9 families with CFEOM and 7 sporadic patients were recruited for this study after informed consent. Genomic DNA was isolated from 5 ml peripheral blood samples according to the standard methods. Direct sequencing was performed after PCR amplification to genomic DNA for detection of KIF21A gene mutation. We identified heterozygous KIF21A mutations in 14 of sixteen patients. Twelve of them harbor the most common mutation, c.2860C > T (p.R954W) and two of them harbor the second most common mutation, c2861G > A(p.R954Q). The R954 mutations account for 87.5% (14/16), in which 75% (12/16) are R954W, 12.5% (2/16) are R954Q. The R954 mutations are also hotspots in Chinese patients with CFEOM.