Homozygosity for a DTDST mutation in a child with multiple epiphyseal dysplasia.

BACKGROUND

Multiple epiphyseal dysplasia (MED) is one of the common hereditary osteochondrodysplasias. Mutations in diastrophic dysplasia sulfate transporter gene (DTDST) result in recessive MED.

OBJECTIVE

To investigate the possible gene mutation in a recessive MED patient.

SUBJECTS: A boy with typical clinical features of recessive MED and his parents.

METHODS

Clinical and radiological evaluations, DTDST gene sequence analysis, and sulfate uptake assay were performed on the patient and his parents.

RESULTS

The patient showed typical symptoms of recessive MED. The radiological evaluation confirmed dysplasia in multiple epiphysis of the patient, while his parents did not show the similar clinical and radiological features. Gene sequence showed the patient was homozygous of A2092T (T689S) mutation, while his parents were both of heterozygous of the same mutation. No such mutation in DTDST gene was found in 81 normal control individuals. The patient showed reduced sulfate uptake ability in dermal fibroblast compared with his parents and normal controls.

CONCLUSION

The homozygous A2092T (T689S) mutation could be one of the mutations in the DTDST gene causing MED.