Yang Yun, Mao Bing, Wang Lixia, Mao Liangwei, Zhou Aifen, Cao Jiangxia, Hu Jiasheng, Zhou Yan, Pan Yanhong, Wei Xiaoming, Yang Shuang, Mu Feng, Liu Zhisheng
Department of Research and Development, BGI‑Central China, Wuhan East Lake High‑Tech Development Zone, Wuhan, Hubei 430075, P.R. China.
Department of Neurology, Wuhan Medical and Health Center for Women and Children, Wuhan, Hubei 430016, P.R. China.
Mol Med Rep. 2015 May;11(5):3687-93. doi: 10.3892/mmr.2014.3135. Epub 2014 Dec 24.
Mutations in the LAMA2 gene cause laminin α‑2 (merosin)‑deficient congenital muscular dystrophies, which are autosomal recessive muscle disorders. Laminin α‑2 is widely expressed in the basement membrane of skeletal muscle, the myotendinous junctions and extra‑synaptically at neuromuscular synapses. In the present study, target next‑generation sequencing was used for mutation detection, and polymerase chain reaction (PCR) analysis and Sanger sequencing were used in the identification of small deletions. Subsequently, quantitative PCR (qPCR) was performed to characterize the identified deletion encompassing exon five of the LAMA2 gene. Two causative mutations were identified using target region sequencing which provided the additional information required to facilitate clinical diagnosis. One heterozygous mutation (p. Lys682LysfsX22) was identified and confirmed by Sanger sequencing, and another heterozygous mutation (Exon5del) was found and validated by qPCR. Co‑segregation analysis indicated that the Exon5del mutation originated from the proband's mother and the previously reported frameshift mutation (p. Lys682LysfsX22) was inherited from the proband's father. To the best of our knowledge, the present study was the first to report an entire exon five deletion in the LAMA2 gene.
LAMA2基因突变导致层粘连蛋白α-2(merosin)缺乏型先天性肌营养不良,这是一种常染色体隐性肌肉疾病。层粘连蛋白α-2在骨骼肌的基底膜、肌腱连接部位以及神经肌肉突触的突触外广泛表达。在本研究中,采用靶向新一代测序进行突变检测,利用聚合酶链反应(PCR)分析和桑格测序鉴定小片段缺失。随后,进行定量PCR(qPCR)以表征所鉴定的包含LAMA2基因第五外显子的缺失。通过靶向区域测序鉴定出两个致病突变,为临床诊断提供了所需的额外信息。通过桑格测序鉴定并确认了一个杂合突变(p.Lys682LysfsX22),通过qPCR发现并验证了另一个杂合突变(Exon5del)。共分离分析表明,Exon5del突变源自先证者的母亲,先前报道的移码突变(p.Lys682LysfsX22)则遗传自先证者的父亲。据我们所知,本研究首次报道了LAMA2基因整个第五外显子的缺失。