Sexually Dimorphic Alterations in the Transcriptome and Behavior with Loss of Histone Demethylase KDM5C

Chromatin dysregulation has emerged as a major hallmark of neurodevelopmental disorders such as intellectual disability (ID) and autism spectrum disorders (ASD). The prevalence of ID and ASD is higher in males compared to females, with un-known mechanisms. Intellectual developmental disorder, X-linked syndromic, Claes-Jensen type (MRXSCJ), is caused by loss-of-function mutations of lysine de-methylase 5C (KDM5C), a histone H3K4 demethylase gene. KDM5C escapes X-inactivation, thereby presenting at a higher level in females. Initially, MRXSCJ was exclusively reported in males, while it is increasingly evident that females with heterozygous KDM5C mutations can show cognitive deficits. The mouse model of MRXSCJ, male Kdm5c-hemizygous knockout animals, recapitulates key features of human male patients. However, the behavioral and molecular traits of Kdm5c-heterozygous female mice remain incompletely characterized. Here, we re-port that gene expression and behavioral abnormalities are readily detectable in Kdm5c-heterozygous female mice, demonstrating the requirement for a higher KDM5C dose in females. Furthermore, we found both shared and sex-specific con-sequences of a reduced KDM5C dose in social behavior, gene expression, and ge-netic interaction with the counteracting enzyme KMT2A. These observations pro-vide an essential insight into the sex-biased manifestation of neurodevelopmental disorders and sex chromosome evolution. Overall design: Bulk poly-(A) RNA sequencing of microdissected forebrains (hippocampus and cortex) of postnatal day 6 mice (P6). Sample genotypes are 4 wild type (WT) males, 4 WT females, 4 Kdm5c-KO males, and 4 Kdm5c-Het females