A case of facioscapulohumeral muscular dystrophy confirmed by D4Z4 analysis

Abstract

Background Facioscapulohumeral muscular dystrophy (FSHD), the third most common inherited muscular disorder, is an autosomal dominant form characterized by progressive weakness and wasting of the facial, shoulder-girdle, upper arm, foot extensor, and pelvic girdle muscles. FSHD is caused by contraction of the polymorphic D4Z4 repeat in the subtelomere of chromosome 4q. However, there is no report of FSHD diagnosed by D4Z4 analysis in Korea. We report the FSHD case confirmed by D4Z4 analysis.

Case A 21 year-old woman was admitted for evaluation of slowly progressive walking difficulty begun at 11 years old. Neurological examination revealed bilateral facial weakness and limb girdle muscle atrophy with moderate scapular winging and minimal scoliosis but without marked paresis and lumbar hyperlordosis. Tendon reflexes and sensory examination were normal. Other three family members also suffered from the similar symptoms. Eletromyographic (EMG) findings showed nonspecific chronic myopathic changes with small amplitude and polyphasic motor unit potential in biceps brachii and the muscle biopsy also showed nonspecific myopathic changes. In genetic study, the deletion of D4Z4 repeat on chromosome 4q35 of the patient was confirmed.

Conclusions This case is the firstly reported FSHD case with the deletion of D4Z4 repeat on chromosome 4q35 confirmed by genetic study in Korea.