PLA2G6复合杂合突变所致不典型神经轴索营养不良一家系分析

PLA2G6 compound complicated mutation in an atypical neuroaxonal dystrophy pedigree

目的探讨1个中国不典型神经轴索营养不良家系临床表现、影像学特点及基因突变情况。方法收集2016年7月至河南省人民医院就诊的1个神经轴索营养不良家系,分析该家系中患者的临床表现及影像学特点,同时对先证者进行全外显子基因检测,捕获致病位点,对致病位点进行一代测序验证,并对家系中其他4名成员、100名家系外正常个体进行突变位点验证。结果该家系中先证者(Ⅱ3)发病年龄17岁,临床主要表现为走路不稳,智力障碍、言语不清、肌张力障碍、癫痫、自主神经功能障碍,影像学表现为小脑萎缩、基底节区异常铁沉积。基因检测发现PLA2G6基因第3号外显子发生p.A80T,第7号外显子发生p.D331Y复合杂合突变,先证者两位姐姐(Ⅱ1,Ⅱ2)亦存在相同突变,先证者父亲携带p.A80T突变,母亲携带p.D331Y突变。先证者大姐(Ⅱ1)10岁左右发病,症状与先证者相似;先证者二姐(Ⅱ2)24岁开始出现步态异常;先证者两位姐姐(Ⅱ1,Ⅱ2)影像学均表现为小脑萎缩。结论我们在中国人群中发现了PLA2G6基因复合杂合突变相关的不典型神经轴索营养不良家系,即p.A80T与p.D331Y突变,此突变很可能与该家系的发病相关。

Objective To analyze the clinical presentation, imaging features, and the mutation of the pathogenic genes in a Chinese Han atypical neuroaxonal dystrophy pedigree. Methods A family of atypical neuroaxonal dystrophy pedigree who came to Henan Provincal People′s Hospital in July 2016 was included. Clinical presentation, imaging features of the pedigree were analyzed, and all exon gene detection of the proband was performed to capture the target variations, then verified by sanger sequence. Another 4 family members′ and 100 normal healthy controls′ gene sequence of the mutations were also verified. Results The proband(Ⅱ3) of the family presented with walking unsteadily, intellectual disability, glossolalia, dystonia, epilepsy, and autonomic nervous dysfunction. The magnetic resonance imaging (MRI) of the proband showed cerebellar atrophy and iron deposit in basal ganglia. The gene detection showed the PLA2G6 gene compound complicated mutation of 80 codon p.A80T in the exon 3 and 331 codon p.D331Y in the exon 7. The two sisters of the proband (Ⅱ1,Ⅱ2) had the same mutation, the father of the proband carried the p.A80T, however, the mother carried the D331Y mutation. One of the proband′s sister (Ⅱ1), whose onset age was 10 years old, had the similar symptoms with the proband. The proband′s another sister(Ⅱ1) had abnormal gait at 24 years old. However, the MRI of the two sisters all showed cerebellar atrophy. Conclusion We report a PLA2G6 compound complicated mutation in an atypical neuroaxonal dystrophy Chinese family, that is the p. A80T and p.D331Y mutation, which may be a pathogenic mutation to cause the family′s disease.