Fronto-Metaphyseal Dysplasia of Gorlin (FMD)

Congenital syndrome involving multiple abnormalities of the face and airway, poorly developed musculature, and limited joint mobility.

Gorlin Syndrome I; Gorlin-Cohen Frontometaphyseal Dysplasia; Gorlin-Holt Syndrome.

First described in 1969 by Robert James Gorlin, an American pathologist and geneticist.

Rare; only 20 to 30 cases are known.

Probable X-linked inheritance, with severe manifestations in males and variable manifestations in females.

Unknown.

Usually asymptomatic at birth and then gradually progressive, particularly contractures. Radiography shows bony changes of dysplasia and osteosclerosis. Metachromatic fibroblasts on blood work.

Prominent supraorbital ridges, incomplete sinus development, micrognathia with decreased angle, high palate, and delayed eruption of teeth. Defective vision and hearing (conductive and sensorineural). Congenital stridor, subglottic stenosis, laryngomalacia, vocal cord paralysis, tracheal web, recurrent respiratory infection, restrictive lung disease, and pulmonary hypertension secondary to scoliosis. Scoliosis, cervical vertebral abnormalities and limited movement, and winged scapula. Flexion contracture of joints (particularly fingers), poorly developed musculature. Cardiac murmurs are common, but often no abnormalities are found. However, mitral valve prolapse has been reported. Bradycardia. Prognosis depends on the progression of ankylosis and thoracic restriction (respiratory failure). Genitourinary tract obstructive anomalies and hydrocephaly are not unusual.

Assessment of associated abnormalities, particularly the airway. A congenital stridor, if present, may be the presenting complaint for diagnosis under anesthesia, and imaging of the airway may be available for assessment. If scoliosis is present, the patient should be assessed for the degree of restrictive lung disease (spirometry) and the presence of pulmonary hypertension (chest radiographs, MRI, blood gases, ECG, and echocardiography). If cardiac murmur is noted, an ECG and echocardiographic evaluation should be performed to rule out arrhythmia and structural abnormality.

Abnormality of the airway is usual in these patients, so the potential for a difficult tracheal intubation should always be considered. If stridor is present, a sedative premedication may not be appropriate and narcotic premedication certainly is contraindicated. Atropine should be considered at induction to reduce the risk of bradycardia and to decrease oral secretions. Induction should be performed after placement of all routine monitoring devices. Inhalational induction in 100% O2 is the preferred technique so that spontaneous ventilation can be maintained and the airway can be fully assessed. Preparation should be made for use of a smaller tube than expected, aiming for a moderate leak. Atropine should be available to treat intraoperative bradycardia. Patient positioning should be done carefully in view of strictures. Intravenous access in the hands may be difficult. Postoperatively, these children may require a period of mechanical ventilation allowing for complete recovery and decreasing the possibility of an increased incidence of tracheal damage and severe stridor after reintubation. Postoperative continuous positive airway pressure has been recommended as an alternative.

Avoid using neuromuscular blocking agents until tracheal intubation and proper lung ventilation are achieved. Care is necessary because of the tendency toward bradycardia ...