A novel GPR143 mutation in a Chinese family with X-linked ocular albinism type 1

Ocular albinism type 1 (OA1) is a genetic disorder characterized by reduced eye pigmentation and nystagmus, which is often accompanied by decreased visual acuity, strabismus and other symptoms, whereas skin and hair color remain normal. The present study aimed to assess the clinical features and perform genotype analysis of a family with OA1, and to determine the disease-causing mutation. A total of 18 family members (nine affected patients and nine normal subjects) from Hainan, China, were recruited to the present study in December 2017. A detailed clinical ophthalmic examination was performed for all participants, including a visual acuity test, anterior segment slit lamp examination, eye fundus examination and optical coherence tomography. Mutations in the G protein-coupled receptor 143 (GPR143) gene were determined by DNA sequencing assays and polymerase chain reaction assays for deletions; all exon coding sequences, exons at the 5′- and 3′-ends, and non-coding region sequences of intron splicing were assessed. Within the family, nine male patients exhibited disease occurrence at the age of 0–6 months. All patients presented with different degrees of iris depigmentation, horizontal jerk nystagmus, foveal hypoplasia and reduced visual acuity. The fundus of only one patient exhibited choroid coloboma; in the remaining patients, their fundi exhibited different degrees of irregular retinal depigmentation. The mutation c.360+5G>T in the GPR143 gene was identified in this family. In conclusion, the present study identified the splicing mutation c.360+5G>T in the GPR143 gene in a Chinese family with OA1 and successfully identified the site. To the best of our knowledge, there have been no previous reports regarding this mutation in any major genome databases; therefore, this outcome may enrich the mutation spectrum of the GPR143 gene.