What does the name mean?
The term ‘diastrophic’ is Greek and means 'crooked'.
How common is diastrophic dysplasia?
Although diastrophic dysplasia occurs in most countries, the highest prevalence is found in Finland (1 in 33,000) where the carrier rate in the population is 1 – 2% (3). The incidence in non-Finnish populations is considerably lower, being 1 in 500,000 live births (6).
Is diastrophic dysplasia inherited?
Diastrophic dysplasia is inherited as an autosomal recessive trait, with very wide variability of phenotypic expression. Approximately 5% of cases constitute new mutations (6).
What causes diastrophic dysplasia?
Diastrophic dysplasia is caused by a mutation in the gene coding for a sulfate transporter protein that is essential for normal cartilage function. This protein is called DTDST and was first identified by Hastabacka and colleagues in 1994 (1). The gene is located on chromosome 5 (5q31-q34). Mutations in the same gene are responsible for lethal chondrodysplasias.
Proteoglycans are complex molecules that absorb water and facilitate load bearing in articular cartilage. Reduction in sulfate transporter concentrations in chondrocytes causes under-sulfation of the proteoglycan matrix and predisposes individuals to early degenerative joint disease. Diastrophic dysplasia affects chondrocyte function in the growth plate, epiphyseal region and other areas such as the trachea.