Bethlem myopathy

In the Bethlem myopathy is a rare muscle disorder that belongs to the group of congenital muscular dystrophies. It is inherited as an autosomal dominant. The disease is characterized by a relatively mild course with proximal muscle weakness and distal joint contractures. Cause of the disease is caused by mutations in one of the 3 genes encoding for collagen VI, a protein of the extracellular matrix. The disease is very rare. So far, less than 100 cases have been described.

History

The first description of the disease is by J. Bethlem and GK Wijngaarden and 1976 was based on the study of three families with a total of 28 patients. In a publication from the year 1988 on a large family with 33 affected patients, the term Bethlem myopathy for this disease has been proposed.

Cause

The cause of the disease is caused by mutations in the genes encoding for collagen VI. Collagen VI is composed of three subunits, which are encoded by three different genes: COL6A1 and COL6A2 on the long arm of chromosome 21 ( 21q22.3 ) and COL6A3 on the long arm of chromosome 2 ( 2q37 ). For all three genes mutations have been described, both point mutations and splice mutations that lead to disease. The disease is inherited as an autosomal dominant trait. VI collagen is a protein of the extracellular matrix, which has a meaning, inter alia, for the connections between the cells ( cell-cell connection).

Clinical picture and course

The Bethlem myopathy is characterized by a low grade muscle weakness of proximal limb muscles. In addition to contractures occur, particularly in the area of the finger joints, but also in other joints. The Bethlem myopathy is characterized by a relatively benign, slowly progressive course. On average, patients are instructed to 25-40 years in a wheelchair.

Swell

  • F. Jerusalem, p Zierz: muscle disorders. Thieme -Verlag 3rd edition 2003, pp. 127 ff ISBN 978-3-13-567803-0
  • Ropper AH, Samuels MA: Adam 's and Victor's Principles of Neurology. McGraw- Hill Companies, 9th edition, p 1374th ISBN 978-0-07-149992-7
Dominance (genetics) Chromosome 2 (human) Neurology (journal) Neurotherapeutics
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