SURF1基因604G→C杂合性错义突变所致Leigh综合征患儿的临床与分子遗传学研究

Clinical and laboratory studies on patients with Leigh syndrome due to (604G→C) heterozygous mutation of SURF1

目的研究因常染色体SURF1基因突变所致Leigh综合征患儿及其家系的临床与分子遗传学特点。方法收集39例Leigh综合征患儿及其家属的外周血白细胞脱氧核糖核酸(DNA),运用聚合酶链反应(PCR)扩增SURF1基因的全部外显子序列,进行正反向序列测定检测突变,采用限制性片段长度多态性(RFLP)分析验证测序结果,并与100名健康成人对照。结果39例Leigh综合征患儿中有5例(12.8%)SURF1基因外显子7存在604G→C杂合性错义突变。5例患儿(男3例,女2例)均因智力或运动障碍于出生后8个月至9.8年来院就诊。其中3例患儿的父母接受了SURF1基因突变分析,发现双亲中一方SURF1基因存在604G→C杂合性错义突变,而另一方及健康对照的相关外显子序列未发现异常。结论我们首次报道了5例SURF1基因604G→C杂合性错义突变导致Leigh综合征的患儿及其家系,频度高达12.8%,提示该突变可能是中国人的热点突变。我们的研究将有助于今后Leigh综合征患者的诊断和遗传咨询。

Objective To discuss the genetic causation in Chinese patients with Leigh syndrome due to SURF1 mutation versus the clinical and genetics characteristics. Methods Genomic DNAs from peripheral blood leucocytes were collected for genetic analysis from 39 patients with Leigh syndrome and some parents of them. All of the 9 exons of SURF1 were amplified by polymerase chain reaction （PCR）. Forward and reverse sequencing were performed for mutation analysis. The detected mutations were further verified by PCR-restriction fragment length polymorphism （RFLP） analysis. Results 604G→C heterozygous mutation of SURF1 was identified from 5 patients （ 12.8% ） with Leigh syndrome who were hospitalized because of mental or motor regression at the age of 8 months to 9. 8 years. A 604G→C heterozygous mutation on SURF1 was also detected in one parent of 3 patients. This mutation was not detected in 100 normal controls. Conclusions Five Chinese patients with Leigh syndrome due to 604G→C heterozygous mutation in SURF1 were reported. In our study, 604G→C heterozygous mutation in SURF1 was detected from 12.8% of the patients with Leigh syndrome. It might be a hot spot mutation in Chinese patients with Leigh syndrome. This study should be helpful for the future diagnosis and genetic counseling of Leigh syndrome.