Objective To observe the clinical characteristics of ocular albinism type 1 (OA1) in China.Methods Sixteen patients with OA1 and eight female carriers (eight OA1 patients and four carriers were from the same family) were enrolled in this study. All subjects were examined for corrected visual acuity, slit-lamp microscopy and GPR143 gene mutation detection. Some subjects also received indirect ophthalmoscopy, photography of anterior segment and ocular fundus, retinoscopy and optical coherence tomography (OCT). Iris pigmentation was divided into type A, B and C according to the above findings. Type A: slight pigmentation; type B: uneven pigmentation; type C: large patch of hypo-pigmentation with hippus. Result The corrected visual acuity of 16 OA1 patients was from 0.1 to 0.3. All the OA1 patients have bilateral horizontal nystagmus without strabismus. All eight subjects received retinoscopy have medium to low hypermetropia and astigmatism. Type A, B and C iris pigmentation were found in eight (50.0%), seven (43.7%) and one (6.3%) patients, respectively. Two (25.0%) carriers have Type A iris pigmentation, and other six carriers (75.0%) were normal. There is no typical albinism retinopathy, however macular foveal structures were never found in these patients. Four carriers have fundus striate or uneven hypo-pigmentation. The macular foveal structure of all the carriers was normal. The macular foveal structure was not found in three subjects who underwent examination of OCT. GPR143 gene mutation was found in all the OA1 patients (100.0%) and all the carriers.Conclusions The major clinical characteristics of Chinese OA1 patients are foveal hypoplasia and GPR143 gene mutation.
ObjectiveTo analyze the pathogenic gene types and phenotypic characteristics of 6 albinism families. Methods A retrospective series of case studies. Six probands of albinism and 20 family members were recruited for this study, 5 probands with clinical manifestations of oculocutaneous albinism (OCA) and 1 proband of ocular albinism (OA). Genomic DNA was extracted from peripheral venous blood which was collected from 6 probands and 20 family members. Genetic variations were screened by whole-exome sequencing or Sanger sequencing and then analyzed the relationship between genotypes and phenotypes. Results Genetic sequencing identified 6 potential pathogenic variants in 4 probands, including 2 compound heterozygous mutations in the 2 genes [TYR (c.1037-7T＞A, c.925_c.926insC), OCA2 (c.2359G＞A, c.587T＞C)] associated with OCA1 and OCA2, and 2 hemizygous mutations in the GPR143[GPR143 (c.11C＞G), GPR143 (c.333G＞A)] associated with OA1, respectively. In which, 5 were novel mutations and confirmed by Sanger sequencing. One case was accorded with OCA in clinical phenotype, but genetic diagnosis was OA1, the others were agreement between clinical diagnosis and genetic diagnosis. Conclusion There are 4 families with mutations in 6 families, representative of 3 type of albinism (OCA1, OCA2, OA1).