Arthrogryposis multiplex congenita in an Arab kindred: update.

We have restudied the genetic and clinical characteristics of a large Arab kindred previously reported in 1970 by Lebenthal et al. [Pediatrics 46:891-899]. At total of 40 affected individuals was identified; all, except one, were products of 22 different consanguineous matings between the parents. The syndrome, which is present at birth, is expressed mainly by flexion contractures at the knees and elbows, with muscle hypotrophy/weakness around the involved joints. Five of the 6 individuals who were originally reported as having congenital and lethal heart defects were limited to one sibship. None of the new cases had heart defect or any associated malformation. Neurologic examination and electrophysiological studies demonstrated a neuropathic (non-myopathic) type of arthrogryposis. This is an autosomal recessive trait with wide variability in expression and possibly incomplete penetrance in the females. Because of the high consanguinity rate, it allows the use of homozygosity linkage studies to map the gene for this disorder.