Résumé :
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Communication n° 646 Danon's disease belongs to the autophagic vacuolar myopathies. It presents with a hypertrophic cardiomyopathy associated with a mild skeletal myopathy and often a mental retardation. The disease is X-linked and is caused by a primary deficiency of lysosome-associated membrane protein-2 (LAMP-2). We report on a swiss family in which two adolescent brothers suffer from a hypertrophic cardiomyopathy with a mild myopathy without mental retardation. Both had a cardiac defibrillator implantation. Their mother and their first cousin (male) both died of sudden death. The skeletal biopsies of one of the adolescents and of his cousin, showed small vacuoles positive for various sarcoplasmic proteins on immunohistochemistry. The cardiac biopsies of the two brothers showed hypertrophic fibers and a few vacuoles. Lamp-2 immunohistochemistry was negative in all muscle and cardiac biopsies. Ultrastructural examination of cardiac muscle in one patient showed numerous vacuoles, containing degenerating mitochondrion, glycogen, small vesicles and granular debris. A novel mutation in exon 4 of the LAMP-2 gene, located on Xq24 was demonstrated.
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