Inherited disorder believed to be an autosomal recessive trait. It is characterized by midface hypoplasia, malformation of the mandible, hypoplastic zygomatic bones, and abnormally pointed chin.
The incidence remains unknown. It seems to be extremely rare or simply because it is underdiagnosed. It might have an ethnicity and geographic distributions.
Transmission appears to be autosomal recessive. Consanguinity in the parents of the first described patients was noted.
The typical facies has prominent eyebrows and ear lobes and a broad, flat nose with a flat nasal bridge. The forehead is usually quite prominent. The face showed a V-shaped configuration with midface hypoplasia, straightening of the gonial angle (the angle between the ramus and the body of the mandible), flattening of the malar eminences, hypoplastic zygomatic bones, and abnormally pointed chin. The opening of the gonial angle leads to overclosure of the mandible with functional prognathism. Alveolar and sutural bone growth in the face is decreased and associated with partial dental agenesis. Craniosynostosis can occur. Skull radiographs show a striking thinning of the calvaria and brachycephaly. The morphology of the cervical vertebrae may be abnormal, and some degree of thoracic scoliosis seems to be common. The lumbosacral spine, however, was described as normal. Cortical thickening of the bone appears to be a prominent feature, most commonly found in the long bones, which can result in encroachment of the medullary cavity. The ribs and the superior pubic ramus are often thin. Minor changes were found in the bones of clavicles, hand, and feet. In one of the patients, thinning of the mandible led to recurrent mandibular fractures (only in one case with a trauma appropriate enough to explain the fracture). All patients in the initially described family were hyperuricemic but not hyperuricosuric, and no other metabolic abnormalities could be detected. However, increased erythrocyte sedimentation rate (30-40 mm/hour) and C3 complement levels have been reported. The plasma fibrinogen level was low in all family members. Diastolic hypertension was present in three of the four initially described patients. The patients are mentally normal.
Precautions before anesthesia
Obtain personal medical history for (spontaneous) fractures. Laboratory examinations should include a complete blood cell count (hematopoiesis may be affected by bone marrow encroachment), electrolytes, creatinine, uric acid, and coagulation tests. Ask about spontaneous or prolonged bleeding. Check for difficult airway management (face mask and tracheal intubation), which should include examination of neck mobility (abnormal cervical vertebrae). If scoliosis is significant, a preoperative lung function test and an echocardiography may be indicated. Assess treatment and efficacy of antihypertensive medication. Check for elevated intracranial pressure in the presence of craniosynostosis.