Madelung deformity in a girl with a novel and de novo mutation in the GNAS gene.

Madelung deformity, a congenital anomaly of the wrist with subluxation of the ulna head, is not a widely recognized feature of Albright hereditary osteodystrophy. Here, we describe a young female with a bilateral Madelung deformity, mild cognitive disability, some dysmorphic facial features, and a type E-like brachydactyly, in whom we identified a novel and de novo mutation (c.476T>C; p.Val159Ala) in exon 6 of the GNAS gene.