[Merosin-deficient congenital muscular dystrophy].
Merosin-deficient-congenital muscular dystrophy (MD-CMD) is characterized by severe progressive muscle weakness that results in contractures, scoliosis, and restrictive pulmonary disease. MD-CMD is the most common and severe form, representing 40% of all CMDs. It is caused by a mutation in the laminin α2 gene (LAMA2-on chromosome 6q22-23) resulting in absence of the laminin α2 chain (aka merosin) around muscle fibres. In addition to the clinical characteristics described above, patients with MD-CMD may present with elevated creatinine kinase (CK) diffuse white matter hyperintensities on brain MRI and seizures (in 30% of patients). Most of these patients have normal intelligence. Approximately one third of MD-CMD patients also have cardiac abnormalities including arrhythmias, and dilated cardiomyopathy. Anesthesia for these patients is required for both diagnostic and surgical procedures. Typical diagnostic procedures include MRI, endoscopies and muscle biopsies. Typical surgical procedures include contracture release, spine fusion, tracheostomy, and gastrostomy.