Merosin-Deficient Congenital Muscular Dystrophy with Polymicrogyria and Subcortical Heterotopia: A Case Report

This paper reports the brain magnetic resonance imaging (MRI) findings of a case of merosin-deficient congenital muscular dystrophy (MDCMD) in a neonate and discusses the spectrum of brain involvement in MDCMD. A neonate presented hypotonia, increased serum creatine kinase levels, and polymicrogyria and subcortical heterotopia on brain MRI involving both posterior temporal and occipital lobes. Although these findings suggested Fukuyama muscular dystrophy, muscle biopsy showed dystrophic changes and an absence of merosin staining. We found that compound heterozygous mutation for c.2049_2050delAG (p.R683fs) and c.5866-2A>G in the LAMA2 gene which encodes Laminin-α2. To our knowledge, this is the second Korean case of MDCMD with polymicrogyria and subcortical heterotopias. This case shows that a range of brain structural malformations can be found in children with MDCMD and that the classification of congenital muscular dystrophy (CMD) is not complete yet, as indicated previously in reports suggesting other unclassified forms of CMD.

Congenital muscular dystrophy type 1A with residual merosin expression / 소아과

Congenital muscular dystrophy type 1A (MDC1A) is an autosomal recessive disorder characterized by hypotonia, elevated serum creatine kinase level, delayed motor milestones, white matter changes observed by brain magnetic resonance imaging, and normal intelligence. A mutation in the laminin alpha2 (LAMA2) gene, located at 6q22-23, is a genetic cause of MDC1A. Patients have merosin (laminin alpha2)-deficient skeletal muscles. However, the degree of merosin expression ranges from total absence to partial reduction. Patients with residual merosin expression have more variable and milder phenotypes than those with absolute merosin deficiency. We observed a Korean girl with MDC1A with residual merosin expression. Clinical presentation of this patient was typical except for late onset of the disease and external capsule involvement. Immunohistochemical staining of muscle fibers including merosin, is important to evaluate patients with hypotonia, delayed motor development, and abnormal white matter changes.

Merosin Deficient Congenital Muscular Dystrophy: A Case with Immunocytochemical Analysis

Primary merosin (laminin alpha2 chain)-deficient congenital muscular dystrophy (CMD) is a uncommon and severe form of CMD, which is caused by the mutations in the laminin alpha2 chain gene. It is an autosomal recessively inherited form of muscular dystrophy that is associated with severe neonatal hypotonia, a high serum creatine kinase level, and abnormal brain imaging without intellectual dysfunction. We report a case of merosin-deficient CMD confirmed by the immunocytochemical analysis of the frozen muscle biopsy. This is the first case of merosin-deficient CMD in Korea.