Tian Mao-Qiang, Chen Xiao-Xi, Li Lei, Lang Chang-Hui, Li Juan, Chen Jing, Yu Xiao-Hua, Shu Xiao-Mei
Department of Pediatrics, Guizhou Children's Hospital/Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, China.
Zhongguo Dang Dai Er Ke Za Zhi. 2022 Jun 15;24(6):699-704. doi: 10.7499/j.issn.1008-8830.2201048.
A boy, aged 5 years, attended the hospital due to progressive psychomotor regression for 2.5 years. Motor function regression was the main manifestation in the early stage, and brain MRI and whole-exome sequencing (WES) of the family showed no abnormalities. After the age of 4 years and 9 months, the boy developed cognitive function regression, and brain MRI showed cerebellar atrophy. The reanalysis of WES results revealed a compound heterozygous mutation, [NM_000520, c.784C>T(p.His262Tyr]), c.1412C>T(p.Pro471Leu)], in the gene. The enzyme activity detection showed a significant reduction in the level of β-hexosaminidase encoded by this gene. The boy was diagnosed with juvenile Tay-Sachs disease (TSD). TSD has strong clinical heterogeneity, and cerebellar atrophy may be an important clue for the diagnosis of juvenile TSD. The reanalysis of genetic data when appropriate based on disease evolution may improve the positive rate of WES.
一名5岁男孩因进行性精神运动发育倒退2.5年入院。运动功能倒退为早期主要表现，患儿脑部MRI及家系全外显子组测序（WES）均未见异常。4岁9个月后，患儿出现认知功能倒退，脑部MRI显示小脑萎缩。对WES结果重新分析发现该基因存在复合杂合突变，[NM_000520，c.784C>T（p.His262Tyr），c.1412C>T（p.Pro471Leu）]。酶活性检测显示该基因编码的β-己糖胺酶水平显著降低。该男孩被诊断为少年型泰-萨克斯病（TSD）。TSD具有很强的临床异质性，小脑萎缩可能是诊断少年型TSD的重要线索。根据疾病进展适时对基因数据进行重新分析可能会提高WES的阳性率。
