脑肌酸缺乏综合征Ⅰ型两家系临床特征及SLC6A8基因变异分析

该文报道2例由SLC6A8基因变异导致的脑肌酸缺乏综合征Ⅰ型（CCDS1）的临床及遗传学特征。2例患儿均为男性，年龄分别为2岁10个月、8岁11个月，主要表现为精神运动发育落后、抽搐。均有一哥哥出现类似症状，患儿1母亲轻度智力低下。经家系基因分析发现X染色体上SLC6A8基因分别存在c.200G > A（p.Gly67Asp）和c.626_627delCT（p.Pro209Argfs^*87）变异，变异均来自患儿母亲。这2个变异分别评级为可能致病性变异、致病性变异，既往未见文献报道。该研究拓展了SLC6A8基因突变谱，对精神运动发育落后、癫痫的男性患者的诊断具有重要意义。

Clinical features and SLC6A8 gene mutations of cerebral creatine deficiency syndrome I: an analysis of two families

This article reports the clinical and genetic features of two cases of cerebral creatine deficiency syndrome I (CCDSI) caused by SLC6A8 gene mutations. Both children were boys. Boy 1 (aged 2 years and 10 months) and Boy 2 (aged 8 years and 11 months) had the clinical manifestations of delayed mental and motor development, and convulsion. Their older brothers had the same symptoms. The mother of the boy 1 had mild intellectual disability. The genetic analysis showed two novel homozygous mutations, c.200G > A(p.Gly67Asp) and c.626_627delCT(p.Pro209Argfs*87), in the SLC6A8 gene on the X chromosome, both of which came from their mothers. These two novel mutations were rated as possible pathogenic mutations and were not reported in the literature before. This study expands the mutation spectrum of the SLC6A8 gene and has great significance in the diagnosis of boys with delayed development, and epilepsy.