Newly described form of X-linked arthrogryposis maps to the long arm of the human X chromosome.

Arthrogryposis is a heterogeneous birth defect characterized by limitation of movement at multiple joints. One in 3,000 infants is born with arthrogryposis, and at least a third of these cases have a genetic cause. Four distinct types of X-linked arthrogryposis have been reported, and a severe lethal form recently was mapped to Xpll.3-qll.2. We now report an extended family affected with a novel variant of X-linked arthrogryposis that involves only the lower limbs. Linkage analysis with polymorphic DNA markers maps the disease locus in this unique family to the long arm of the human X chromosome between DXS1220 and DXS1205 in Xq23-27.