Chaki M, Sengupta M, Mukhopadhyay A, Subba Rao I, Majumder P P, Das M, Samanta S, Ray K
Indian Institute of Chemical Biology, Kolkata, India.
Ann Hum Genet. 2006 Sep;70(Pt 5):623-30. doi: 10.1111/j.1469-1809.2006.00247.x.
Oculocutaneous albinism (OCA) is a heterogeneous group of autosomal recessive disorders characterized by an abnormally low amount of melanin in the eyes, skin and hair, and associated with common developmental abnormalities of the eye. Defects in the tyrosinase gene (TYR) cause a common type of OCA, known as oculocutaneous albinism type 1 (OCA1). The molecular basis of OCA has been studied extensively in different population groups, but very little information is available on Indian patients. Our investigation covering thirteen ethnic groups of India, some representing >20 million people, revealed that among 25 OCA families 12 were affected with OCA1, and that these cases were primarily due to founder mutations in TYR. We detected nine mutations and eight SNPs in TYR, of which six mutations (five point mutations & one gross deletion) were novel. In contrast to most reports describing compound heterozygotes, the presence of homozygotes in 10 out of the 12 pedigrees underscores the lack of intermixing between these ethnic groups in India. Haplotype analysis suggested a few founder chromosomes causing the disease in the majority of the patients. Direct detection of the mutations prevalent in specific ethnic groups could be used for carrier detection and genetic counselling.
眼皮肤白化病（OCA）是一组常染色体隐性遗传疾病的统称，其特征为眼睛、皮肤和毛发中黑色素含量异常低，并伴有常见的眼部发育异常。酪氨酸酶基因（TYR）缺陷导致一种常见的OCA类型，称为眼皮肤白化病1型（OCA1）。OCA的分子基础已在不同人群中得到广泛研究，但关于印度患者的信息却非常少。我们对印度的13个民族进行了调查，其中一些民族人口超过2000万，结果显示在25个OCA家庭中，有12个家庭患有OCA1，这些病例主要是由TYR基因的始祖突变引起的。我们在TYR基因中检测到9个突变和8个单核苷酸多态性（SNP），其中6个突变（5个点突变和1个大片段缺失）是新发现的。与大多数描述复合杂合子的报告不同，在12个家系中有10个家系存在纯合子，这突出表明印度这些民族之间缺乏通婚。单倍型分析表明，少数始祖染色体导致了大多数患者患病。直接检测特定民族中普遍存在的突变可用于携带者检测和遗传咨询。
