The ARMC9 gene encodes for Armadillo (ARM) repeats containing protein that is a part of basal body of cilium. Biallelic pathogenic variants in ARMC9 cause Joubert Syndrome 30. So far in thirteen families reported with Joubert syndrome 30, fifteen homozygous or compound heterozygous variants (missense, nonsense, splice site, synonymous-splice site) were reported to cause Joubert Syndrome 30. Functional studies are indicative of loss of function of the ARMC9 protein due to pathogenic variants.

Genetic Testing
Variants in ARMC9 can be identified using molecular genetic testing, either directly by targeted sequencing of ARMC9 gene or by exome/ genome sequencing.