Joubert syndrome is a phenotypically heterogeneous ciliopathy classically defined by the presence of a ‘molar tooth sign’ in neurological imaging studies caused by brain anomalies such as cerebellar vermian hypoplasia/aplasia. JBTS24 also results in polymicrogyria and pachygyria. Neurological issues such as delayed psychomotor development, absent speech, ataxia, spasticity, hyperreflexia, dysmetria, hypotonia and impaired gait are common. Other symptoms include postaxial polydactyly of the hands and feet and ophthalmological defects such as nystagmus and hyperopia.
Joubert syndrome has a prevalence of 1/80,000 to 1/100,000 live births and does not appear to have a gender or racial bias. The congenital disorder has an onset in infancy and diagnosis can be made based on clinical features and radiological investigations. Prognosis depends on the severity of symptoms. While some children may have mild forms of the disorder, others suffer from severe motor disability and multi-organ defects. Treatment is currently symptomatic and supportive. Patients may benefit from physical, occupational and speech therapy.