A NEWLY RECOGNIZED AUTOSOMAL-DOMINANT LIMB-GIRDLE MUSCULAR-DYSTROPHY WITH CARDIAC INVOLVEMENT

Sixty-five members of three families with limb girdle muscular dystrop hy (LGMD) underwent neurological, cardiological, and ancillary investi gations. Thirty-five individuals were diagnosed as having slowly progr essive autosomal dominant LGMD. Symmetrical weakness started in the pr oximal lower limb muscles, and gradually upper limb muscles also becam e affected. Early contractures of the spine were absent. Contractures of elbows and Achilles tendons were either minimal or late. Serum crea tine kinase activity was normal to moderately elevated. Electromyogram and muscle biopsy were consistent with a mild muscular dystrophy. Car diological abnormalities, found in more than one-half the patients, in cluded dysrhythmias and atrioventricular (AV) conduction disturbances presenting as bradycardia, syncopal attacks necessitating pacemaker im plantation, and sudden cardiac death. There was a significant relation between the severity of AV conduction disturbances and age. In nearly all patients, neuromuscular symptomatology preceded cardiological inv olvement. The early recognition of this previously not described, auto somal dominant LGMD with life-threatening cardiac involvement offers a n opportunity for therapeutic intervention.