Cartilage Oligomeric Protein Disorders/Pseudoachondroplasia:
One of more common skeletal dysplasia’s. Not clinically apparent at birth (may see platyspondyly on x-ray) – growth retardation is seen around 1 – 3 years.
Autosomal dominant, but most are new mutations.
Characterised by short limbed dwarfism and ligamentous laxity
Histologically – dilated rough endoplasmic reticulum; accumulation of abnormal cartilage oligomeric matrix protein (COMP)
Aetiology – mutation in gene coding for COMP
Hands and feet are short and broad. Facies are normal.