Identification of pathogenic genes in a family with oculocutaneous albinism / 中华皮肤科杂志

ABSTRACT

Objective:To detect mutations in a pedigree containing two brothers with oculocutaneous albinism (OCA) by whole-exome sequencing and Sanger sequencing.Methods:Clinical data were collected from a pedigree with OCA, and DNA was extracted from peripheral blood samples obtained from the proband and other family members. The whole-exome coding region of the proband was directly sequenced by whole-exome sequencing technology to identify potential pathogenic mutations, and Sanger sequencing was conducted to verify the gene mutations.Results:Both the proband and his younger brother presented with generalized white skin, golden-yellow hair, bilateral nystagmus, photophobia, translucent iris, conjunctival congestion, and refractive errors of both eyes. The proband′s parents, grandparents, maternal grandparents, and children were all phenotypically normal, and his parents′ marriage was non-consanguineous. Three heterozygous mutations were identified in the OCA2 gene of both the proband and his younger brother, including a nonsense mutation c.1290T>A, and 2 missense mutations c.1363A>G and c.1204T>C. The mutation c.1204T>C has not been previously reported, and was a novel gene mutation in the OCA2 gene. In addition, 1 heterozygous mutation c.1204T>C was identified in the OCA2 gene in the proband′s father and daughter, 2 heterozygous mutations c.1290T>A and c.1363A>G were found in the OCA2 gene in the proband′s mother, and 1 heterozygous mutation c.1290T>A was identified in the OCA2 gene in the proband′s son and the daughter of the proband′s younger brother.Conclusions:Three gene mutations were identified in the OCA2 gene in the 2 patients with OCA, and the nonsense mutation c.1290T>A may be the pathogenic mutation causing the clinical phenotype of this family. These findings expand the pathogenic mutational spectrum of the OCA gene.