Emery-Dreifuss muscular dystrophy (EDMD) and
limb-girdle muscular dystrophy type 1B (
LGMD1B) are characterized by cardiac dysrhythmias, late-onset
cardiomyopathy, slowly progressive skeletal
myopathy and
contractures of the neck, elbows and ankles. The causative mutation is either in the
emerin gene (X-linked recessive EDMD) or
lamin A/C gene (autosomal dominant EDMD2 or
LGMD1B). We report three cases of EDMD, EDMD2 and
LGMD1B. A 14-yr-old boy showed limitation of cervical flexion and
contractures of both elbows and ankles. Sinus arrest with junctional escape beats was noted. He was diagnosed as X-linked recessive EDMD (MIM 310300). A 28-yr-old female showed severe wasting and weakness of humeroperoneal muscles. Marked limitation of cervical flexion and
contractures of both elbows and ankles were noted. Varying degrees of
AV block were noted. She was diagnosed as autosomal dominant EDMD2 (MIM 181350). A 41-yr-old female had
contractures of both ankles and limb-girdle type
muscular dystrophy. ECG revealed atrial
tachycardia with high grade
AV block. She was diagnosed as autosomal dominant
LGMD1B (MIM 159001). Cardiac dysrhythmias in EDMD and
LGMD1B include
AV block,
bradycardia, atrial
tachycardia,
atrial fibrillation, and atrial standstill, causing
sudden death necessitating pacemaker implantation. Cardiologists should know about these unusual
genetic diseases with conduction defects, especially in young adults.