Clinical and radiological presentation of a child with progressive pseudorheumatoid dysplasia

Introduction The role of WNT pathway in bone formation and maintenance has been extensively studied since the identification of mutations in key signalling WNT mediators in diseases with high or low bone-mass phenotypes. In humans, loss-of-function mutations in WISP3, encoding Wnt1-inducible signaling protein 3, cause progressive pseudorheumatoid dysplasia (PPD), an autosomal recessive form of spondyloepiphyseal dysplasia tarda. Individuals with PPD appear normal at birth, have subtle clinical symptoms by 3 years of age and develop later a severe degenerative joint disease with multiple contractures and reduction in joint mobility. Radiologically patients with PPD have multiple sites of epiphyseal enlargement in addition to platyspondyly.