VPS13D and microcephaly: The second transcriptomic memory gene identified in both data sets was Vps13d, which encodes Vacoular Protein Sorting Homolog D, and a frameshift mutation in Vps13d is the primary ethiology of Cohen syndrome, a rare genetic disease characterized by trucal obesity as well as developmental delay, mental retardation, microcephaly, and hypotonia (Kolehmainen et al. 2004).