Researchers at Queen Fabiola Children’s University Hospital, Brussels, Belgium, report a 7-year-old Belgian boy with a 5 months-onset congenital muscular dystrophy and laminopathy caused by a de novo heterozygous LMNA gene mutation. Muscle weakness and wasting affected the axial muscles, proximal upper and distal lower extremities, with rapid development of joint contractures and spine rigidity. Serum CK was moderately elevated. Muscle biopsy showed a dystrophic pattern with normal immunochemical studies, excluding classic forms of CMD. [1]
COMMENT. Previous reports of 15 cases of CMD with LMNA mutations [2] cited by the authors distinguish two groups, I (n=30) a severe group with absent motor development, and II (n=12), a dropped-head syndrome phenotype with a milder disease in children who initially sat and walked, and then developed neck weakness. Laminopathies are a heterogeneous group of diseases that include autosomal dominant Emery-Dreifuss muscular dystrophy and limb-girdle muscular dystrophy type IB.