Langer-Giedon syndrome or trichorhinophalangeal syndrome type 2 is characterized by the association of intellectual deficit and numerous other anomalies including redundant skin, multiple cartilaginous exostoses, characteristic facies and cone-shaped phalangeal epiphyses. The severity and number of these malformations varies between patients. The characteristic facial anomalies consist of a bulbous nose, wide prominent philtrum, thin upper lips, cauliflower ears, sparse hair and a small mandible. Growth retardation, microcephaly, hypotonia and hearing problems have also been reported. The exostosis affects mainly the extremities of the long bones and may lead to pain, functional problems or bone deformation. Exostoses and cone-shaped phalangeal epiphyses appear during the first 5 years of life, during which respiratory infections are frequent. The prevalence is unknown. The syndrome is transmitted in an autosomal dominant manner, but many sporadic cases have been reported. The disease is caused by a microdeletion in chromosome 8q23.3-q24.13 leading to the loss of at least two genes: TRPS1 and EXT1. Langer-Giedon syndrome can be differentiated from trichorhinophalangeal syndrome type 1 by the presence of the exostoses. Early diagnosis of Langer-Giedon syndrome is essential in order to provide genetic counselling to affected families, and to assure orthopaedic follow-up and management of the growth and hearing problems.
Last update: April 2006