question: Which syndromes are associated with mutations in the EZH2 gene?
answer: EZH2 mutations that cause Weaver syndrome are primarily missense variants and the rare truncating mutations reported to date are in the last exon, suggesting that simple haploinsufficiency is unlikely to be generating the overgrowth phenotype although the exact mechanism has not yet been determined. Recent studies have shown that EZH2 mutations are often associated with RUNX1 mutations in MDS patients, although its pathological function remains to be addressed. These data show that mutations in EZH2 cause Weaver syndrome. The EZH2 gene is a homolog of the Drosophila Polycomb group (PcG) gene enhancer of zest, a crucial regulator of homeotic gene expression.