Cerebellar Disorders in Children. 2012 eds. Chapter11: Joubert Syndrome and Related Disorders. Mac Keith Press.

Joubert syndrome (JS) and related disorders (JSRD) are a group of highly heterogeneous conditions sharing a complex midbrain-hindbrain malformation known as the molar tooth sign (MTS). The main neurological features include hypotonia, ataxia, developmental delay, intellectual disability, altered breathing pattern in the neonatal period and abnormal eye movement. These are variably associated with multiorgan manifestations, mainly of the retina, kidneys and liver. Such clinical variability requires a multidisciplinary approach for diagnosis and management.
JSRD are inherited in autosomal recessive fashion, with the exception of one form following X-linked inheritance. Ten causative genes have been identified to date, with relevant genotype-phenotype correlations. Notably, all genes encode for proteins of the primary cilium or the centrosome, making JSRD part of an expanding group of diseases called “ciliopathies”.