AHI1

This gene is apparently required for both cerebellar and cortical development in humans. This gene mutations cause specific forms of Joubert syndrome-related disorders. Joubert syndrome (JS) is a recessively inherited developmental brain disorder with several identified causative chromosomal loci. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Oct 2008]

Abelson Helper Integration Site 1

Involved in vesicle trafficking and required for ciliogenesis, formation of primary non-motile cilium, and recruitment of RAB8A to the basal body of primary cilium. Component of the tectonic-like complex, a complex localized at the transition zone of primary cilia and acting as a barrier that prevents diffusion of transmembrane proteins between the cilia and plasma membranes. Involved in neuronal differentiation. As a positive modulator of classical Wnt signaling, may play a crucial role in ciliary signaling during cerebellum embryonic development.

Cellular protein localization
Central nervous system development
Ciliary basal body-plasma membrane docking
Cilium assembly
Cloaca development
Heart looping
Hindbrain development
Kupffer's vesicle development
Left/right axis specification
Morphogenesis of a polarized epithelium
Negative regulation of apoptotic process
Otic vesicle development
Photoreceptor cell outer segment organization
Positive regulation of polarized epithelial cell differentiation
Positive regulation of receptor internalization
Positive regulation of transcription by RNA polymerase II
Pronephric duct morphogenesis
Pronephric nephron tubule morphogenesis
Regulation of behavior
Retina layer formation
Specification of axis polarity
Transmembrane receptor protein tyrosine kinase signaling pathway
Vesicle-mediated transport

Cilium basal body; Centriole; Adherens junction. In the retinal photoreceptor cell layer, localizes at the connecting cilium.

Joubert syndrome 3 (JBTS3): A disorder presenting with cerebellar ataxia, oculomotor apraxia, hypotonia, neonatal breathing abnormalities and psychomotor delay. Neuroradiologically, it is characterized by cerebellar vermian hypoplasia/aplasia, thickened and reoriented superior cerebellar peduncles, and an abnormally large interpeduncular fossa, giving the appearance of a molar tooth on transaxial slices (molar tooth sign). Additional variable features include retinal dystrophy and renal disease. Joubert syndrome type 3 shows minimal extra central nervous system involvement and appears not to be associated with renal dysfunction.