LAMA2 stop-codon mutation: merosin-deficient congenital muscular dystrophy with occipital polymicrogyria, epilepsy...

Merosin-deficient congenital muscular dystrophy (MD) type 1A (MDC1A) is one of the most frequent forms of CMD in Western countries. The classical form, characterized by a total lack of laminin alpha2 chain expression, usually shows severe clinical features; cases with complete laminin alpha2 deficiency and mild phenotype have also been reported, although the mechanisms underlying the lack of genotype-phenotype correlation have not been elucidated. Epilepsy and focal cortical dysplasia-in addition to the classical diffuse white matter abnormalities-have been described in some of these patients associated with cognitive deterioration. We report on a patient with total laminin alpha2 deficiency due to a homozygous stop-codon mutation in the LAMA2 gene, with mild evolution. When 6.9 years old, she developed focal occipital seizures and absence-like status when awake, with probable relation to an extensive bilateral occipital micropolygyria. Soon afterwards she lost ambulation and developed cognitive deterioration. Our case confirms that the clinical spectrum of MDC1A is more heterogeneous than previously thought.