This study utilized the same high resolution methylation array used here and was able to distinguish individuals with Sotos syndrome (secondary to pathogenic NSD1 mutations) from individuals with non-pathogenic mutations of NSD1, as well as from cases of the clinically similar disorder Weaver syndrome, caused by mutations in the histone methyltransferase EZH2 (Enhancer of Zeste, Drospholia, Homolog 2). Here, PRDM9 is linked to Weaver syndrome.