一个X-连锁肾上腺脑白质营养不良家系的基因变异分析

Genetic analysis of a pedigree affected with X-linked adrenoleukodystrophy

目的明确1个主要表现为下肢痉挛性截瘫的X-连锁肾上腺脑白质营养不良家系的基因诊断,为临床诊断提供早期依据.方法从患者及其母亲的外周血白细胞中提取基因组DNA;应用二代测序技术设计一个包含表型为痉挛性截瘫疾病的检测包,首先对先证者进行分析,寻找可疑基因变异,再通过PCR及直接测序分析患者及其父母相应的基因组片段,进一步确认发现的基因变异.结果先证者(男性)及其母亲均有行走困难的临床主诉.二代测序结果发现先证者在位于X染色体的ABCD1基因(转录本编号:NM_000033)存在c.623T>A(p.V208E)变异,直接测序证实其母亲也携带该位点的同一杂合变异.结论对于临床上病因不明的单纯性痉挛性截瘫,需要考虑鉴别X-连锁肾上腺脑白质营养不良.

Objective To explore the genetic basis for a pedigree affected with X-linked adrenoleukodystrophy presenting as spastic paraplegia of the lower limbs.Methods Genomic DNA was extracted from peripheral blood samples of the patient and his mother.Potential variant was detected with a panel for genes associated with spastic paraplegia.Candidate variant was verified by PCR and Sanger sequencing.Results Both the proband and his mother presented with walking difficulty.A previously known variant,c.623T>A(p.V208E),was identified in the ABCD1 gene mapped on chromosome X in both.Conclusion X-link adrenoleukodystrophy should be taken into account as a possible diagnosis for this pedigree.