Hypoglossia-Hypodactylia

Description

Hypoglossia-hypodactyly syndrome is characterized by a hypoplastic mandible, absence of the lower incisors, hypoglossia, and a variable degree of absence of the digits and limbs. Intelligence is normal (Hall, 1971).

Hall (1971) classified what he termed the 'syndromes of oromandibular and limb hypogenesis,' which comprised a range of disorders with hypoglossia in common. Type I included hypoglossia and aglossia in isolation. Type II included hypoglossia with hypomelia/hypodactylia. Type III included glossopalatine ankylosis with hypoglossia or hypoglossia and hypomelia/hypodactyly. Type IV included intraoral bands with fusion with hypoglossia or hypoglossia and hypomelia/hypodactyly. Type V included several syndromes, such as Hanhart syndrome, Pierre Robin syndrome (261800), Moebius syndrome (157900), and amniotic band syndrome (217100). Hall (1971) noted that complete aglossia or adactylia had not been reported, and suggested that 'hypoglossia-hypodactylia' is a more accurate term.

See also hypoglossia and situs inversus (612776).

Clinical Features

Hanhart (1950) described 3 cases of the same disorder; 2 patients were related and, in the third, the parents were consanguineous. Features included peromelia and micrognathia.

In Turkey, Tuncbilek et al. (1977) observed 3 sporadic cases, each with consanguineous parents, and espoused autosomal recessive inheritance. However, general consanguinity rate may be high in the population in question.

Epicanthus was a feature in a patient reported by Shokeir (1978). Robinow et al. (1978) observed discordant monozygotic twins; it is noteworthy, although perhaps coincidental, that the parents were second cousins. They also described a case with associated 'apple peel' bowel (243600), which is thought to arise through obliteration of the superior mesenteric artery. This suggested to them that the aglossia-adactylia syndrome might likewise be the result of vascular occlusion, as in the embryopathy experimentally induced by Jost and Poswillo.

Opitz (1982) concluded that the disorder is a nonmendelian developmental disturbance.

Buttiens and Fryns (1986) described Hanhart syndrome in brother and sister. These persons had retrognathia, microstomia, and symmetric severe limb reduction defects, but normal tongue. Thus, it is arguable whether it should be called Hanhart syndrome.

Chandra Sekhar et al. (1987) reported with photographs 2 remarkable cases in which micrognathia was extreme. One patient was a male who died in the neonatal period. Structural abnormalities of the middle ear were described. The second case was a 14-year-old boy with bilateral conductive hearing loss and bilateral absent thumbs.

Robertson and Bankier (1999) described an intellectually normal 20-year-old man with severe manifestations of the Hanhart syndrome. He was born to nonconsanguineous parents with no history of exposure to teratogens. Three other sibs were normal. He was 150 cm tall and his head circumference was 53 cm. An extreme degree of micrognathia was present with almost no mandible evident. The tongue was very small with greatly reduced mobility. Upper limb anomalies included right synbrachydactyly of digits 1-2-3 and on the left a terminal transverse defect of the wrist. There was a transverse defect at the level of the left knee for which a prosthesis had been fitted. The right foot had 3 digits.

De Smet and Schollen (2001) described 2 newborns with severe limb deformities and hypoglossia, with micro- and retrognathia. One patient had a transverse agenesia just below the knee in both legs and below the elbow of both arms. The second child had less severe deformities. The authors provided a discussion of the classification of these disorders.

Camera et al. (2003) described a boy with oromandibular limb hypogenesis and radiologic demonstration of 'angel-shaped phalanx' (105835).

Dogan et al. (2010) reported a Turkish infant, born of unrelated and healthy parents, with Hanhart syndrome. He had a small tongue, micrognathia, and bilateral complete absence of the hands and feet. Radiographs showed absence of the carpal and metacarpal bones, mesomelia of the left tibia, absence of the right tibia, and a rudimentary right tarsal bone. The patient died of pneumonia at age 9 months. Dogan et al. (2010) noted that all reported cases had occurred sporadically.