关键词: 先天性肌营养不良；　LAMA2基因；　基因突变

Abstract: 　Objectives　To explore the clinical characteristics and diagnostic methods of congenital muscular dystrophy caused by LAMA2 gene mutation. Methods　The clinical data of merosin-deficient congenital muscular dystrophy type 1A (MDC1A) in a child were retrospectively analyzed. Results　The boy first visited the hospital at 2 years and 2 months of age. His clinical manifestations were psychomotor retardation, inability to stand and walk, and slurred speech. The levels of creatine kinase were significantly increased. MRI indicated that the white matter around the anterior and posterior horn of bilateral ventricles and the deep center of the centrum semiovale showed long T1, long T2 and FLAIR sequence high signal. Genetic testing revealed that the child had a complex heterozygous mutation which was splicing mutation derived from the father (c.47181G>A) and frameshift mutation derived from the mother (c.4529delC). No such reports have been found in the literature and databases. According to the ACMG guidelines, both variants were considered pathogenic, and the child was diagnosed with MDC1A. Conclusions　MDC1A is caused by LAMA2 gene mutation. Muscle biopsy and LAMA2 gene detection can make a definite diagnosis. The genetic mutations found in this study are reported for the first time and it expands the gene mutation spectrum of congenital muscular dystrophy.

Key words: 　congenital muscular dystrophy;　LAMA2 gene;　gene mutation