Novel Gene LAMA2 Mutation and Exonic Deletion Underline Merosin-Deficient Congenital Muscular Dystrophy 1A in a Chinese Family

Merosin Deficient Congenital muscular dystrophy type 1A (MDC1A) is a rare kind of congenital muscular dystrophy.
Here we report a Chinese case with a genetic diagnosis exposing a novel point mutation and a novel exonic deletion in the causative gene LAMA2. We collected the medical history and did physical examination for the case. A set of auxiliary examination was performed for the diagnosis. The patient exhibited notable proximal weakness and was severely hypotonic. The CK increased slightly. The brain MRI exposed leukodystrophy. The electromyogram suggested myogenic muscle damage. Merosin was completely absent in the visual field of muscle biopsy. Gene testing exposed that the proband was a compound heterozygote with a heterozygous nonsense mutation c.817A > T in exon 5 and a deletion involved exon 4 of LAMA2 gene. The point mutation derived from the mother while the exonic deletion derived from the father. The asymptomatic sister carried the point mutation c.817A > T.
This case expands the mutation spectrum of MDC1A and highlights that the diagnosis of MDC1A should be suspected in the presence of an elevated CK and abnormal white matter.