用新一代外显子捕获测序技术诊断眼皮肤白化病Ⅲ型一例

Diagnosis of a case with oculocutaneous albinism type Ⅲ with next generation exome capture sequencing

目的对一例疑为眼皮肤白化病的患儿进行临床和遗传学分析。方法对患儿进行临床检查，提取患儿及其父母基因组DNA，采用新一代外显子目标区域捕获测序技术对患儿进行基因突变分析，并对疑似致病性突变进行患儿及其父母的Sanger测序验证及生物信息学预测。结果患儿歪头视物，视力低下，伴有双眼水平冲动型眼球震颤，毛发棕黄色。基因测序显示患儿TYRP1基因存在c．1214C〉A（P．T405N）和c．1333dupG杂合突变，分别遗传自其母亲和父亲。生物信息学预测为致病性突变。结论患儿为Ty尺纠基因复合杂合突变引起的眼皮肤白化病Ⅲ型，TYRP1复合杂合突变致病的病例尚未见报道。

Objective To explore the clinical and genetic features of a Chinese boy with oculocutaneous albinism. Methods The clinical features of the patient were analyzed. The DNA of the patient and his parents was extracted and sequenced by next generation exome capture sequencing. The nature and impact of detected mutation were predicted and validated. Results The child has displayed strabismus, poor vision, nystagmus and brown hair. DNA sequencing showed that the patient has carried compound heterozygous mutations of the TYRP1 gene, namely c. 1214C〉A （p. T405N） and c. 1333dupG, which were inherited from his mother and father, respectively. Neither mutation was reported previously. Conclusion The child has suffered from oculocutaneous albinism type Ⅲ caused by mutations of the TYRP1 gene.