Tay-Sachs病1例临床及HEXA基因突变分析

目的探讨Tay-Sachs病的临床表现及HEXA基因突变特点。方法回顾分析1例经基因检测诊断的TaySachs病患儿的临床资料,并复习相关文献。结果男性患儿,1岁7个月,主要临床表现为精神运动发育倒退、明显惊跳、抽搐。眼底检查示黄斑部樱桃红斑,己糖胺酶A活力仅为0.1 nmol/(mg·h)。目标序列捕获和二代测序检测发现患儿HEXA基因外显子区域存在两处杂合突变c.1445A>T和c.1052T>C,分别引起氨基酸变化p. E482V和p.L351P。Sanger测序验证显示2个突变分别来源于父亲和母亲,为复合杂合突变。结论 Tay-Sachs病是一种罕见的神经变性病,酶活性及基因检测有助明确诊断。

The clinical feature and HEXA gene mutation analysis of Tay-Sachs disease in a child

Objective To explore the clinical manifestations of Tay-Sachs disease and the characteristics of HEXA gene mutation. Methods The clinical data of Tay-Sachs disease diagnosed by gene testing in a child were retrospectively analyzed and the related literature was reviewed. Results A 1-year-7-month-old boy mainly presented with psychomotor retardation, startle reaction and seizures. Ophthalmoscopy showed macular cherry erythema, and hexosaminidase A activity was only 0.1 nmol/(mg·h). Target sequence capture and second-generation sequencing revealed two heterozygous mutations, c.1445 A>T and c.1052 T>C, in the exon region of the HEXA gene in the child, causing amino acid changes p. E482 V and p.L351 P respectively. The results of Sanger sequencing confirmed that the two mutations were from father and mother respectively and were compound heterozygous mutation. Conclusion Tay-Sachs disease is a rare neurodegenerative disease. Enzyme activity and genetic testing can help to clarify the diagnosis.