Langer-Giedion Syndrome: A Distinct Phenotype

Trichorhinophalangeal syndrome (TRPS), as the name suggests is a rare genetic disorder which affects the tricho (hair), rhino (nose), phalanges (digits)[1] and has been classified into three types. Trichorhinophalangeal syndrome type II (TRPS2) is also known as Langer-Giedion syndrome (LGS). It was first described by Andreas Giedion, a Swiss pediatric radiologist and Leonard O Langer Jr, an American radiologist. TRPS2 combines features of trichorhinophalangeal syndrome type I (TRPS1) and multiple exostoses[2]. It is characterized by sparse hair, multiple cone shaped epiphyses, multiple cartilaginous exostoses, bulbous nasal tip, thickened alar cartilage, upturned nares, prominent philtrum, large protruding ears and mild mental retardation[3]. Multiple cartilaginous exostoses distinguishes TRPS2 from TRPS1. Exostoses are multiple projections of bone capped by cartilage, mostly seen in the metaphyses as well as diaphyses of long bones. Flat bones, vertebrae and the ribs may also be affected. As the bone continues to grow, the exostoses appear to migrate towards the diaphysis. At puberty as the growth plate fuses, the linear growth ceases and no new exostoses develop[4]. There are no trigger factors for development of exostoses