Chong Yeow Kuan, Ma Louis Che Kwan, Lo Kit Lin, Lee Clary Ka Lai, Mak Chloe Miu, Kan Amanda Nim Chi, Lam Ching Wan
Genetic Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Hong Kong Special Administrative Region.
Department of Paediatrics, United Christian Hospital, Hong Kong Special Administrative Region.
Eur J Paediatr Neurol. 2014 Jul;18(4):532-5. doi: 10.1016/j.ejpn.2014.03.003. Epub 2014 Mar 12.
Alpha-dystroglycanopathies are a group of diseases due to reduced glycosylation of alpha-dystroglycan, which commonly result from mutations in POMT1, POMT2, and POMGnT1. Patients with alpha-dystroglycanopathies present with muscular, cerebral, and ocular involvements with differing severities. We reported a boy who presented with muscular dystrophy, developmental delay, and non-specific white matter lesions. Mutation analysis of POMT1 was performed and revealed two novel mutations, a substitution mutation (c.176T>G) and a duplication mutation (c.2059dupC) which results in premature termination of translation. In-silico prediction in five different platforms concurred that the substitution is damaging, and functional studies by immunofluorescence revealed lack of staining in the carbohydrate moiety of alpha-dystroglycan, confirming the molecular findings in a functional manner. In conclusion, we reported the first case of genetically confirmed alpha-dystroglycanopathy due to mutations in POMT1 in Chinese.
α-肌营养不良糖蛋白病是一组由于α-肌营养不良糖蛋白糖基化减少所致的疾病,通常由POMT1、POMT2和POMGnT1基因突变引起。α-肌营养不良糖蛋白病患者会出现不同严重程度的肌肉、大脑和眼部受累症状。我们报告了一名患有肌肉萎缩症、发育迟缓及非特异性白质病变的男孩。对POMT1进行了突变分析,发现了两个新突变,一个替换突变(c.176T>G)和一个重复突变(c.2059dupC),后者导致翻译提前终止。五个不同平台的电子预测均一致认为该替换具有损害性,免疫荧光功能研究显示α-肌营养不良糖蛋白的碳水化合物部分缺乏染色,从功能角度证实了分子研究结果。总之,我们报告了中国首例经基因确诊的因POMT1突变导致的α-肌营养不良糖蛋白病。