Psychopharmacology in children with genetic disorders of epigenetic and chromatin regulation

Table 1 Definition of variant subgroups

Variants in single genes that are known to have a primary epigenetic regulatory function (n=9)	Other genetic diagnoses identified (n= 23)
ARID1B SMARCA2 EHMT1 MECP2 duplication MECP2 deletion SMC3 NSD1 SETD2 SPEN (55)	KIAA2022 SCN1A 16p13.1 microduplication 22q11.2 Deletion^a(n=3) OPHN1 Klinefelter syndrome (56)^b 22q13 deletion^a Trisomy 14 mosaicism SHANK3 GRIN1	Waardenburg syndrome type 2A 15q13.1 deletion 8p23 translocation and partial deletion Xp22.3 microduplication Fragile X premutation (57)^b Chromosome 17 copy number variant CDKL5 Phenylketonuria (PKU) Tuberous sclerosis complex, TSC2 mutation (n=2)

Classification based on the gene list published by Fahrner, Bjornsson et al., [34, 37], and the curated gene list by Valencia et al [36]. Table 1 is classified and annotated based on currently known methylation alterations; however, it is likely that additional variants with methylation alterations will be identified in future, especially for copy number variants. We note that some variants categorized as “other” do have published epigenetic signatures in blood, presumably due to the presence of a gene with epigenetic regulatory function in the CNV (^a), and that there are methylation changes noted with sex chromosome aneuploidy [44] and fragile X [45] (^b)

ISSN: 1866-1955