NAV2 and Global developmental delay: Stepwise filtering of ES analysis retained two compound heterozygous variants in NAV2 (NM_001244963.2): c.5179_5180delAG, p.(Leu1728Trpfs*2) and c.6757delA,p.(Ile2253*) in a female with developmental delay and a diagnosis of cerebellar hypoplasia and dysplasia.