TRAPPC4 and Intellectual disability: Family J revealed two homozygous variants, one is a missense variant c.5941G>A; p.V1981I in HERC1 gene and other is splice site variant (c.454 + 3A>G) in TRAPPC4. HERC1 protein is involved in the membrane trafficking via guanine nucleotide exchange factors (GEF) and previously reported as a novel candidate gene for causing intellectual disability (Ortega-Recalde et al., 2015).