Diastrophic dysplasia is a rare disease characterized by short stature with short limbs and malformations of the joints leading to multiple joint contractures, mainly affecting shoulders, elbows, interphalangeal joints and hips.
Prevalence is estimated at 1/100,000. The syndrome is transmitted in an autosomal recessive manner and it is caused by mutations in the SLC26A2 gene (transporter of sulfate of the dysplasia: DTDST), it is located at the locus 5q31-q34 and codes for a sulfate transporter with predominant expression in the cartilage. Mutations in the same gene are implicated in recessive multiple epiphyseal dysplasia, type 1b achondrogenesis and type 2 atelosteogenesis.
At birth, children have bilateral clubfoot, short limbs, wrist deformation, adduction thumbs, cleft palate and hypoplastic jaws. In the first months of life, cysts appear in the outer ear. Growth is slow, scoliosis is frequent and develops progressively. The deformations of the joints are serious and can lead to a limitation of joint movement, or hyperlaxity.
The expression of the disease is variable, with very severe and other moderate forms, which may have a very late diagnosis.
Gene or region studied
- SLC26A2 (DTDST)