Joubert Syndrome

Genetic disorder characterized by cerebral malformations (vermis and brainstem) resulting in severe coordination (ataxia) and breathing (sleep apnea, hyperpnea) disorders.

Cerebellar Vermis Agenesis Syndrome; Cerebelloparenchymal Disorder Type IV; Chorioretinal Coloboma with Cerebellar Vermis Aplasia; Coloboma, Chorioretinal with Cerebellar Vermis Aplasia; Joubert-Boltshauser Syndrome.

Peroxisomal disease named after Marie Joubert, a Canadian neurologist who reported the first cases in 1989, in Montreal.

Autosomal recessive. Gene map locus is 9q34.3.

Unknown.

Typical “molar tooth” sign on axial magnetic resonance imaging (MRI) through the malformed pontomesencephalic junction. Prenatal diagnosis may be suggested by ultrasonographic features. Clinical features. Abdominal and cerebral ultrasonography diagnosis in the neonatal period.

During the neonatal period, variable combinations of central nervous system, eye, and renal abnormalities. Agenesis of the cerebellar vermix with cystic dilatation of the fourth ventricle and poor respiratory control. Episodes of tachypnea attacks alternating with apneas. Severe psychomotor retardation and ataxia. Abnormal eye movements and bilateral coloboma. Abdominal ultrasonographs reveal cortical renal cysts and interstitial renal fibrosis. Other malformations, including polydactyly (fingers and toes), cleft lip/palate, tongue malformations, and seizures, may exist. Renal function may deteriorate. Prognosis is poor.

Check respiratory function, perform pulmonary function tests if patient collaboration permits [forced vital capacity (FVC), forced expiratory volume at 1 second (FEV1); maximal expiratory flow rate (MEFR), residual volume (RV)]. Perform arterial blood gases in room air in all cases. Check renal function by checking electrolytes, blood urea nitrogen, and creatinine. The administration of premedication is unadvised.

Children with this syndrome have abnormalities of respiratory control as a consequence of neuronal changes in the brainstem and cerebellum. They are extremely sensitive to the respiratory depressant effects of anesthetic agents, including nitrous oxide. Anesthesia using inhalational induction, intermittent positive pressure ventilation, avoidance of opioids, and close postoperative monitoring are recommended.

Opioid hypersensitivity. Respiratory depression following nitrous oxide. Children very sensitive to the depressant effects of any anesthetic agent.

Louis-Bar Syndrome: Autosomal recessive progressive cerebellar ataxia with oculomotor apraxia, telangiectasias of the conjunctivae, choreoathetosis, immunodeficiency, recurrent infections, increased sensitivity to ionizing radiations, and tendency to develop malignancies.