Clinical, myopathological and genetic research of a patient with distal myopathy caused by caveolin-3 deficiency

Abstract

Objective To report the clinical, myopathological and genetic features of a patient with distal myopathy caused by caveolin-3 (CAV3) deficiency. Methods The patient was a 27-year-old female. She had an onset symptom of asymmetric lower extremities weakness. The proximal limb-girdle muscles were involved subsequently. Clinical data of this patient were collected. The leg muscle magnetic resonance imaging (MRI) and an open biopsy of left tibialis anterior muscle were performed. In addition to histological, enzyme histochemical staining and ultrastructural examination, immunohistochemical staining with antibody against CAV3 was done. CAV3 gene was analyzed in the patient and her parents. Results T1-weighted enhanced skeletal muscle MRI of the lower limbs showed the abnormal signal in distal and proximal muscles. Muscle biopsy showed moderate dystrophic changes and immunostaining for CAV3 showed reduced plasmalemma in the muscle fibers. Gene analysis disclosed a heterozygous c. 136G>A(p.Ala46Thr)mutation in the CAV3 gene, and the patient's parents did not have this mutation. Conclusions We report a distal myopathy case caused by c. 136G>A(p.Ala46Thr) mutation in the CAV3 gene, who had an onset symptom of asymmetric lower extremities weakness. The proximal limb-girdal muscles were also involved. This would help clinical doctors to know more about this rare myopathy. Key words: Distal myopathies; Caveolin 3; Biopsy; Genetic testing