Bethlem Myopathy: A Case Report

Bethlem myopathy occurs in autosomal-dominant inheritance and limb-girdle distribution of weakness. It is a rare and benign myopathy. It is characterized by the following salient clinical features: slow progression of limb-girdle weakness from childhood onward with periods of arrest for several decades; contractures of fingers, elbows and ankles: and absence of cardiac involvement. We presented a 24-year-old woman with complaint of difficulty in walking, sitting and arising from the chair or bed since age of 16. Routine nerve conduction velocity and needle electromyogram revealed a myopathy, however, serum CPK and LDH were normal. Muscle biopsy revealed non-specific myopathic change withoutdystrophin deficiency. Her first son, had right lower limb weakness with frequent falling down episodes since age of 6. Mild elbow contracturewasalso noted. The electromyogram testing had a myopathic change. Wide variety of autosomal-dominance of clinical features of muscle weakness and joint contractures were also found in her maternal-line pedigree.