Multiple epiphyseal dysplasia

Multiple epiphyseal dysplasia (MED):
Group of disorders characterised by dysplasia (irregular and delayed ossification) of several epiphyses of tubular bones. Autosomal dominant transmission is more common.
Dwarfing in mild

Variable clinical presentation:
Childhood  waddling gait, difficult climbing stairs
Adult  premature osteoarthritis

Types:
MED 1:
• mutation in gene coding for COMP  similar to pseudoachondroplasia, but with more subtle protein alteration

MED 2:
• mutation in gene coding for the alpha-2 polypeptide chain of type IX collagen
• results in non-inflammatory articular cartilage degeneration