The aim of this study was to investigate the clinical features and DGUOK gene mutations of an infant with mitochondrial DNA depletion syndrome (MDS). The patient (more than 7 months old) manifested as hepatosplenomegaly, abnormal liver function, nystagmus and psychomotor retardation. Genetic DNA was extracted from peripheral blood samples of the patient and her parents. Targeted Exome Sequencing was performed to explore the genetic causes. Sanger sequencing was carried out to confirm the detected mutations. The sequencing results showed that the patient was a compound heterozygote for c.679G>A and c.817delT in the DGUOK gene. The former was a reportedly pathogenic missense mutation of maternal origin, while the latter, a frameshift mutation from the father, has not been described yet. The findings in this study expand the mutation spectrum of DGUOK gene, and provide molecular evidence for the etiologic diagnosis of the patient as well as for the genetic counseling and prenatal diagnosis in the family.
该文报道1例线粒体DNA耗竭综合征患儿的临床特征及DGUOK基因突变特点。患儿女, 婴儿期起病, 表现为肝脾肿大、肝功能异常、眼球震颤和精神运动发育迟缓等。提取患儿及其父母外周血DNA标本, 采用外显子组捕获测序技术检测致病突变, 并对检测到的突变进行Sanger测序验证。结果显示患儿为DGUOK基因突变c.679G>A和c.817delT的复合杂合子, 前一个突变来自于母亲, 为已报道致病性突变; 后者来自于父亲, 是一个未见文献报道的新突变。该研究扩展了DGOUK基因突变谱, 为患儿病因诊断及该家系的遗传咨询和产前诊断提供了分子依据。