Ciliopathies

Common symptoms in the neonatal period include tachypnoea/dyspnoea, nystagmus, vertical gaze palsy and muscular hypotonia. Later, cerebellar ataxia with delayed motor development may be observed. Cognitive development can range from normal intelligence to severe deficits. In some cases, Joubert syndrome may be associated with nephronophthisis, optic nerve coloboma, liver fibrosis and polydactyly.

The frequency of Joubert syndrome is estimated to be approximately 1:100,000. A genetic cause is detected in 40–50% of cases.

Pathogenic variants have been identified in multiple genes, reflecting the substantial gene locus heterogeneity of the condition.

Joubert syndrome is inherited in an autosomal recessive manner.

Due to its association with nephronophthisis and overlapping features with disorders affecting ciliary function, Joubert syndrome is considered part of the group of ciliopathies.

• Fleming et al. 2017, Clin J Am Soc Nephrol 12:1962
• Kroes et al. 2016, Eur J Hum Genet 24:214
• Wolf & Hildebrandt 2011, Pediatr Nephrol 26:181
• Boltshauser & Isler 1977, Neuropädiatrie 8:57
• Joubert et al. 1969, Neurology 19:813