Branchio-Skeleto-Genital Syndrome

Genetic disorder resulting in anomalies of branchial arch, skeleton, and genitalia.

BSG Syndrome; El Sahy-Waters Syndrome.

Unknown. Only one case report of three boys from a single family.

Presumed autosomal recessive trait. All the affected brothers were offspring of a first-cousin couple in a family pedigree with a history of consanguinity. Variable expression of the syndrome is thought to occur, as two other siblings had mental retardation, but no other features of the condition.

Several laboratory investigations to determine the nature of the chromosomal or metabolic errors failed to delineate a cause. Histologic and radiologic analysis of the dental cysts showed they were dentigerous (an odontogenic cyst surrounding the crown of an impacted tooth). Teeth from these patients had an unusual form of dentine dysplasia, mainly affecting the bulbar areas, which had not been described previously.

Clinical course, morphologic appearance, radiology of mandible and maxilla (with multiple dental cysts), and oral histopathology of teeth (abnormal dentine dysplasia).

Features include mental retardation, seizures, brachycephalic skull, cervical fusion between second and third vertebrae, Schmorl nodes (i.e., herniations of the intervertebral disc through the vertebral endplate) in the lumber area, pectus excavatum, and penoscrotal hypospadias. Children have class III malocclusions with hypoplasia of the maxilla resulting in relative mandibular prognathism, a bifid uvula or partial cleft palate. Multiple dental cysts are present in the maxilla and mandible with misalignment of all the teeth of the upper jaw. Nasal bones are broad and flat, with a wide nasal tip and flared alar cartilages. All patients had hypertelorism, nystagmus of the right eye on right and left gaze, and divergent strabismus and slight ptosis of the right eye. Incomplete expression of the syndrome may be associated with mental retardation, but normal morphology.

Obtain a full history of problems associated with the syndrome: mental retardation (sedative premedication may be advantageous), seizures (anticonvulsant therapy and efficacy), and degree of pectus excavatum. Evaluate the airway for potential difficulties (poor dentition, limited neck mobility, class III malocclusion, cleft palate). Consider anticholinergic premedication to decrease airway secretions if fiberoptic intubation is planned. Obtain a complete blood count.

If difficult airway management is anticipated, an awake fiberoptic tracheal intubation (mental retardation may reduce cooperation) or inhalational induction with maintained spontaneous ventilation should be considered. Regional anesthesia techniques can be used, especially for urologic procedures, provided no other specific contraindications are present (e.g., thrombocytopenia in patients taking sodium valproate).

Muscle relaxants should be avoided until the airway has been secured. Avoid potentially epileptogenic drugs such as methohexital, ketamine, and enflurane. Sodium valproate may cause hepatic dysfunction, thrombocytopenia, and pancreatitis. Several of the commonly used anticonvulsant agents can cause sedation and hepatic enzyme induction resulting in altered pharmacokinetic and pharmacodynamic responses to various anesthetic agents. Patients receiving anticonvulsant medication should be continued on their regimen until surgery, and medications should be given parentally postoperatively until oral intake is tolerated.