伴皮层下囊肿的巨脑性白质脑病一家系MLC1基因突变分析

Analysis of MLC1 gene mutation in a Chinese family with megalencephalic leukoencephalopathy with subcortical cysts

摘要:

收集伴皮层下囊肿的巨脑性白质脑病(MLC)先证者及其父母的临床资料,采用聚合酶链反应和DNA 直接测序法进行MLC1 基因突变检测。患儿临床表现为运动发育迟缓、巨颅,头颅MRI 扫描显示弥漫性脑白质肿胀,伴双侧额顶部皮层下囊肿。基因测序结果发现患儿携带MLC1 基因2 个杂合突变:第3 外显子的错义突变c.217G>A(p.Gly73Arg)和第9 内含子的剪接位点突变c.772-1G>C in IVS9-1。患儿的父母均为c.772-1G>C in IVS9-1 杂合突变携带者,无临床症状。可推测患儿c.772-1G>C in IVS9-1 突变来源于父母;c.217G>A(p.Gly73Arg)为新生突变,为国内外首次报道。

Abstract:

The clinical data of a patient with megalencephalic leukoencephalopathy (MLC) with subcortical cysts and her parents were collected. MLC1 gene mutation was detected by polymerase chain reaction and direct DNA sequencing. The patient presented with motor developmental delay and giant skull, and brain magnetic resonance imaging showed diffuse white matter swelling accompanied by subcortical cysts in bilateral frontal and parietal lobes. Gene sequencing identified two heterozygous mutations of MLC1, including missense mutation in exon 3 (c.217G>A, p.Gly73Arg) and splice site mutation in intron 9 (c.772-1G>C in IVS9-1). The patient's parents both had heterozygous mutation c.772-1G>C in IVS9-1 with normal phenotype. It can be presumed that c.772-1G>C in IVS9-1 comes from the parents, and c.217G>A (p.Gly73Arg) is a de novo mutation.