Definition:

Trichorhinophalangeal syndromes (TRPS) is a rare peripheral dysostosis with mainly autosomal dominant inheritance. Three different forms of TRPS are known: type I (TRPS1), type II (TRPS2) and type III (TRPS3). They are characterized by sparse hair, bulbous pear-shaped nose, long and flat philtrum, thin upper lip, and protruding ears. Skeletal abnormalities that are frequently observed include epiphyses of the middle phalanges with shortened metacarpals, hip malformations, and short stature. The causative gene is TRPS1 that was shown to be a regulator of the Wnt signaling pathway in mouse.