Severe progressive respiratory involvement requiring ventilator support in autosomal recessive Bethlem myopathy. A case report

Bethlem myopathy (BM) was first described in 1976 by Bethlem and van Wijngaarden in patients who presented a myopathy characterized by slowly progressive muscle weakness and typical flexion contractures of the long finger flexors, wrists, elbows, pectoralis muscles and ankles. Patients with Bethlem myopathy usually become symptomatic during the first or second decade of life. The condition is in most cases slowly progressive and more than two thirds of patients over 50 years of age may require aids for ambulation. Inheritance is usually autosomal dominant. However, patients with autosomal recessive (AR) BM have been recently reported in Literature. Cardiac involvement is usually absent. Respiratory muscle involvement necessitating nocturnal respiratory support is rarely reported in association with severe weakness later in life.
We describe a further case of ARBM in a 52-year-old man who presented a slowly progressive myopathy but developed a severe progressive respiratory involvement requiring ventilatory support.