Tricho-Rhino-Phalangeal Dysplasia Type II

Genetic multisystem disorder (ectodermal dysplasia) characterized by mild postnatal growth deficiency with mental retardation, thin hair, unusual facial features, brachydactyly, and multiple exostoses.

(Figure)

Langer-Giedion Syndrome; Acrodysplasia V; Acrodysplasia Dysostoses Syndrome; Alè-Calò Syndrome; Giedion-Langer Syndrome; Klingmüller Syndrome; Multiple Exostoses-Mental Retardation (MEMR) Syndrome; Trichorhino Auriculophalangeal Multiple Exostoses (TRAMPE) Dysplasia; Trichorhinophalangeal Syndrome with Exostoses.

Postnatal growth retardation associated with mild to moderate mental retardation and multiple cartilaginous exostoses described by A. Giedion, a Swiss Radiologist and L. Langer, an American radiologist.

Rare. Both sexes affected equally.

Usually sporadic but some cases autosomal dominant. Chromosome deletion extending from 8q24.11 to 8q24.13. One of the contiguous gene syndromes (group of disorders associated with chromosomal microdeletions or microduplications).

Contiguous gene syndrome involving loss of functional copies of TRPS 1 and EXT 1 genes. Deletion of 8q24.13 results in bone exostoses and mental retardation especially when large pieces of 8q are deleted.

Clinical features supported by genetic analysis. Long bone radiographs reveal cone-shaped epiphyses and the presence of exostoses.

Exostoses of bone with tendency for bone fracture and variable growth, hyperextensible joints. Scoliosis may be present. Redundant skin. Microcephaly, characteristic appearance with bulbous broad nose, bushy eyebrows, sparse scalp hair, dental abnormalities. Mental retardation, neonatal hypotonia, delayed speech development, hearing loss. Recurrent respiratory infections. Prune-belly sequence. Ureteral reflux, persistent cloaca, congenital nephrotic syndrome. Aplasia of epiglottis may be present.

Assessment of severity of syndrome, previous bony problems, and degree of mental retardation. Exclusion of respiratory infection clinically and, if indicated, by chest radiography. Assessment of genitourinary abnormalities and referral to exclude abnormalities may be indicated. Assessment of rare complications such as prune belly and epiglottic aplasia must be conducted.

Premedication may be indicated if patient is uncooperative because of mental retardation. Intravenous access may be difficult because of the redundant skin. Careful positioning and padding is highly recommended because of the tendency to spontaneous bone fracture.

Prophylactic antibiotics may be indicated for respiratory or urogenital indications.

Tricho-Rhino-Phalangeal Dysplasia Type I: Syndrome characterized by characteristic facial anomalies (bulbous nose, cone-shaped epiphyses), high-arched palate, and horizontal groove on the chin. Also includes hypoplastic nails and short metatarsal and metacarpal joints. Mental retardation is not associated with this medical condition.