In this study, we describe an 18‐year‐old woman with global developmental delay, severely limited speech, hypotonia, microcephaly, and facial dysmorphisms, who was found to have a novel de novo single‐base frameshift deletion in EHMT1 (Chr9(GRCh37): g.140637927_140637928del; NM_024757.4(EHMT1): c.928_929del; NP_079033.4: p.Arg310Aspfs*4) by whole exome sequencing (WES) after a protracted diagnostic odyssey. This evidence concerns the gene EHMT1 and Global developmental delay.