The most frequent mutation, 862C>T (R279W), is a mild mutation giving the rMED phenotype when homozygous and mostly DTD when compounded; occurrence at a CpG dinucleotide and its panethnic distribution suggest independent recurrence.
A homozygous R279W mutation was recently found in the diastrophic dysplasia sulfate transporter gene, DTDST, in a patient with MED who had a club foot and double-layered patella.
We had not seen a case of homozygosity for c862t (R279W) until we analysed DNA from a 36 year old male with tall-normal stature (180 cm) who asked for genetic counselling for suspected multiple epiphyseal dysplasia.