A Novel Frameshift Mutation in Two Siblings with Merosin-deficient Congenital Muscular Dystrophy

Abstract

We present two siblings with elevated serum creatine kinase concentrations, developmental delay, muscle weakness, and contractures of the lower limbs. Cranial magnetic resonance imaging revealed diffuse white matter hyperintensity in both siblings. In the older sister, muscle biopsy was performed; immunohistochemical studies showed a dystrophic pattern and merosin deficiency. With the diagnosis of merosin-deficient congenital muscular dystrophy (MDC1A), LAMA2 gene mutation analysis revealed an NM_000426.3:c.163_163delA; (p.N55Mfs*16) homozygous frameshift mutation in the siblings. This mutation leads to a premature stop codon and has not been reported previously in the literature.

Keywords

• merosin
• muscular dystrophy
• white matter hyperintensity