PT  - JOURNAL ARTICLE
AU  - Gao, Christine W
AU  - Lin, Wan-Ying
AU  - Riddle, Ryan C
AU  - Chopra, Sheetal
AU  - Boukas, Leandros
AU  - Hansen, Kasper D
AU  - Björnsson, Hans T
AU  - Fahrner, Jill A
TI  - Growth retardation in a mouse model of Kabuki syndrome 2 bears mechanistic similarities to Kabuki syndrome 1
AID  - 10.1101/2023.10.15.562327
DP  - 2023 Jan 01
TA  - bioRxiv
PG  - 2023.10.15.562327
4099  - http://biorxiv.org/content/early/2023/10/16/2023.10.15.562327.short
4100  - http://biorxiv.org/content/early/2023/10/16/2023.10.15.562327.full
AB  - Growth retardation is a characteristic feature of both Kabuki syndrome 1 (KS1) and Kabuki syndrome 2 (KS2), Mendelian disorders of the epigenetic machinery with similar phenotypes but distinct genetic etiologies. We previously described skeletal growth retardation in a mouse model of KS1 and further established that a Kmt2d−/− chondrocyte model of KS1 exhibits precocious differentiation. Here we characterized growth retardation in a mouse model of KS2, Kdm6atm1d/+. We show that Kdm6atm1d/+ mice have decreased femur and tibia length compared to controls and exhibit abnormalities in cortical and trabecular bone structure. Kdm6atm1d/+ growth plates are also shorter, due to decreases in hypertrophic chondrocyte size and hypertrophic zone height. Given these disturbances in the growth plate, we generated Kdm6a−/− chondrogenic cell lines. Similar to our prior in vitro model of KS1, we found that Kdm6a−/− cells undergo premature, enhanced differentiation towards chondrocytes compared to Kdm6a+/+ controls. RNA-seq showed that Kdm6a−/− cells have a distinct transcriptomic profile that indicates dysregulation of cartilage development. Finally, we performed RNA-seq simultaneously on Kmt2d−/−, Kdm6a−/−, and control lines at Days 7 and 14 of differentiation. This revealed surprising resemblance in gene expression between Kmt2d−/− and Kdm6a−/− at both time points and indicates that the similarity in phenotype between KS1 and KS2 also exists at the transcriptional level.Competing Interest StatementHTB is a consultant for Mahzi therapeutics. The other authors have no conflicts of interest.