obsolete autosomal dominant limb-girdle muscular dystrophy type 1B true OBSOLETE. Autosomal dominant limb-girdle muscular dystrophy type 1B (LGMD1B) is a subtype of autosomal dominant limb girdle muscular dystrophy characterized by a variable age of onset of progressive shoulder and hip girdle weakness, with inferior limbs usually being affected prior to upper limbs, and mild joint contractures. LGMD1B is also associated with cardiac dysrhythmias, including atrioventricular conduction blocks, and late-onset dilated cardiomyopathy, that may lead to sudden death. MONDO:0008033 Emery-Dreifuss muscular dystrophy 2, autosomal dominant