Multiple epiphyseal dysplasia (MED) is a clinically and genetically heterogeneous chondrodysplasia with either autosomal dominant or recessive inheritance. The phenotypic spectrum ranges from mild to severe. Patients usually present with joint pain and stiffness, waddling gait and/or mild short stature in childhood. Some patients, however, remain asymptomatic until adult age and present with early-onset osteoarthritis of the large weight-bearing joints. Typical radiographic findings include delayed and irregular ossification of the epiphyses in multiple joints. Spinal changes, if present, are mild. Mutations in five different genes, cartilage oligomeric matrix protein (COMP), collagen IX (COL9A1, COL9A2 and COL9A3), and matrilin-3 (MATN3) can cause the autosomal dominantly inherited forms of MED. Mutations in the diastrophic dysplasia sulfate transporter gene (DTDST or SLC26A2) can cause the recessively inherited form of the disorder. Mutations in COL2A1 cause various chondrodyplasias, which phenotypically overlap with MED.

Copy number variation (CNV) analysis of the MED genes using high density targeted (HDT) array is also offered as a panel. Additionally, CTGT offers a comprehensive test (both NGS panel and HDT array panel) for these genes. Panel genes are also offered as individual sequencing and deletion/duplication tests, unless otherwise indicated.

The MED panel consists of seven genes: COL2A1, COMP, COL9A1, COL9A2, COL9A3, MATN3 and SLC26A2.