[Joubert syndrome: report of four adult siblings affected]

Joubert syndrome is a rare, autosomal recessive genetic transmission illness, with ten associated genes discovered at the time. They code for primary ciliary proteins; that is why Joubert syndrome is considered a 'ciliopathie'. The primary cilia are involved in cell proliferation and neuronal migration in cerebellum and axonal brain, being essential for their proper development. The first description was made in 1969 by Marie Joubert and colleagues. They reported four cases with partial or total agenesis of the cerebellar vermis, apnea-hyperpnea neonatal episodic, abnormal eye movements, ataxia and mental retardation. One of them also showed occipital meningoencephalocele.

Four adult individuals affected by the disease are described. All of them biological siblings, within 24-35 years old, and presenting the 'sign of the molar' midbrain in their clinical and neuroimaging. It is an entity characteristic, with the image formed by agenesis or hypoplasia of the cerebellar vermis, superior cerebellar peduncle narrow, flatten, thickened and elongated with a lack of decussation and deep interpeduncular fossa at the level of the isthmus and upper bridges.

This study shows the need for early disease diagnosis to ensure proper monitoring, therapeutic approach and family genetic counseling, as well as the role of the cerebellum in cognitive functions and intelligence development.