Diastrophic dysplasia: clinical, radiological, cytogenetic and molecular characterization of a patient

Abstract

Diastrophic dysplasia is an osteochondrodysplasia that is inherited in an autosomal recessive pattern. It was first described by Lamy and Maroteaux in 1960. This disorder is characterized by short stature, normal head size, micromelia, kyphoscoliosis, cleft palate, cystic masses in auricles, talipes equinovarus, joint contractures and abduction of thumbs (“hitchhiker thumbs”). During the neonatal period mortality is high (25%), generally due to respiratory obstruction. For those who survive, prognosis is usually good. Intelligence and sexual development are normal. In 1991 Hästbacka et al. identified the DTD locus in the 5q31-q34 region. In 1996 the Treacher Collins Syndrome Collaborative Group showed that the gene is located on 5q32-q33.1. The DTDST gene encodes a sulphate transporter, whose alteration results in the production of undersulphated proteoglycans in the cartilage matrix. We present a female patient who shows the phenotypic and radiologic characteristics of this disorder. Molecular studies (Necker Hospital, Paris) identified two mutations in the DTDST gene: one previously reported in the literature and a novel mutation.