title: Muscle pathology of myotonia congenita.
abstract: We have investigated the muscle biopsies of 8 patients with myotonia congenita. There were 2 families with autosomal recessive inheritance (5 cases), 1 with autosomal dominant inheritance, and 2 sporadic cases. Mild abnormalities were seen with routine pathological preparations which were nondiagnostic. Histochemical studies of fiber subtypes demonstrated a complete absence of Type 2B muscle fibers in all of our patients regardless of the type of inheritance. this is the first reporot of an entity in which there is a consistent absence of a muscle fiber type, and some speculation has been made as to the possible causes.
mesh_terms: D000251:Adenosine Triphosphatases / Q000032:analysis; D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D009132:Muscles / Q000201:enzymology / Q000473:pathology*; D009224:Myotonia Congenita / Q000235:genetics / Q000473:pathology*
chemical_list: D000251:Adenosine Triphosphatases