POLRMT and syndromic intellectual disability: Due to the now widespread use in Estonia of NGS methods in a routine clinical setting, our clinic's findings have contributed to identification of some new IMD, such as an intellectual disability syndrome with single‐nucleotide variants in O‐GlcNAc transferase (OMIM: #300255),24, 25 a mitochondrial RNA polymerase (POLRMT) defect (OMIM: #601778),26 a syntaxin‐5 defect (OMIM: #603189),27 3‐methylglutaconic aciduria caused by CLPB deficiency (OMIM: #616254),28 and a novel (ovario‐) leukodystrophy related to AARS2 pathogenic variants (OMIM: #612035).29