NAV2 and Cerebellar dysplasia: Despite robust evidence underscoring the importance of NAV2 in CNS development and function in both vertebrate and invertebrate models, no patients have been reported with mutations in NAV2. To explore whether Neuron Navigator 2 affects human brain and cerebellum development and other phenotypes, we screened (whole or clinical) exome sequencing (ES) data from individuals affected with (sporadic) molecularly undetermined cerebellar dysplasia for de novo or biallelic variants in the NAV2 gene.