Bethlem myopathy

Bethlem myopathy is a muscle disease that is inherited mostly in an autosomal dominant pattern and is classified as a congenital form of limb-girdle muscular dystrophy. It has two types according to which collagen is affected. The first is caused by a mutation in one of the three genes coding for type VI collagen, and the second, formerly called myopathic-type Ehlers-Danlos syndrome, by a mutation in the gene coding for type XII collagen. Typical signs are Gowers sign, toe walking, multiple joint contractures especially of the fingers, skin abnormalities and weakness of the muscles nearest the trunk. There is no cardiac involvement, which separates it from Emery-Dreifuss muscular dystrophy. There is no cure and treatment relieves symptoms. J. Bethlem and G. K. van Wijngaarden described it in 1976.