Diastrophic Dysplasia

Diastrophic dysplasia (DTD) is a rare growth disorder in which patients are usually short, have club feet, and have malformed joints. Although found in all populations, it is particularly prevalent in Finland.

Symptoms

• Scoliosis, a form of clubbed foot bilaterally
• Malformed pinnae with calcification of the cartilage
• Premature calcification of the costal cartilages
• 'Hitchhiker' thumb due to deformity of the first metacarpal.
• Cleft palate (in some cases)

Causes

DTD is caused by mutation of the SLC26A2 gene located on chromosome 5. This gene encodes a sulfate transporter. This is consistent with the observation of unusual concentrations of sulfate in various tissues of DTD patients. Sulfate is important for skeletal joints because cartilage - the shock-absorber of joints - requires sulfur during its manufacture. Adding sulfur increases the negative charge within cartilage, which contributes to its shock-absorbing properties.

DTD is inherited in an autosomal recessive pattern.

Treatment

Currently there is no cure for the disease. A great deal of further research must be done before this condition is fully understood and effective therapies are developed.

References:

Genes and Diseases, National Library of Medicine, USA.
Online Mendelian Inheritance in Man