Ulnar Hypoplasia is an extremely rare disorder, so far reported in only a handful of families around the world. It is a form of mesomelic dysplasia that is characterized by severe isolated upper limb mesomelia, and ulnar hypoplasia with radial bowing.
Mégarbané et al (2005) reported the second case of Ulnar Hypoplasia in medical literature. They described a Lebanese family, in which both father and son were affectedwith mesomelic shortening of the upper limbs, prominent bowed radii, limitation of elbow movement, dislocation of radial heads, and ulnar deviations. The son was a product of a consanguineous union.