EZH2 and Weaver syndrome: EZH2 c.2050 C>T (p.R684C) is the most common heterozygous pathogenic variant in unrelated patients with Weaver syndrome (14, 16) and lies within the catalytic Su(var)3-9, Enhancer of Zeste, and Trithorax (SET) methyltransferase domain, which is highly conserved across species (27–30).