Novel GPR143 mutations and clinical characteristics in six Chinese families with X-linked ocular albinism

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.

Six families with OA1 were recruited from our pediatric and genetic eye clinic. Genomic DNA was prepared from venous leukocytes. The coding regions of GPR143 were amplified by polymerase chain reaction, and subsequently analyzed by direct sequencing. The variations detected were further evaluated in available family members as well as controls.

Mutations in GPR143 were identified in each of the six families: c.849delT (p.Val284SerfsX15); c.238_240delCTC (p.Leu80del); c.658+1G>A, c.353G>A (p.Gly118Glu); g.1103_7266del6164 (p.Gly84AlafsX65), which resulted in a deletion of exons 2 and 3; and g.25985_26546del562 (p.Gly296ValfsX26), which resulted in a deletion of exon 8. Of these six, c.353G>A is a known mutation, while the other five are novel. All affected patients had nystagmus, poor visual acuity, and foveal hypoplasia. However, hypopigmentation of the iris and fundus was very mild in these patients.

Five novel mutations and one known mutation were identified in six Chinese families with OA1. These results expand the mutation spectrum of GPR143, and demonstrate the clinical characteristics of OA1 among the Chinese.