Kleefstra-like Syndrome

EHMT2 (G9a) and EHMT1 (GLP) are proteins that methylate lysine 9 on histone H3 (H3K9), crucial for development, differentiation, and cancer. EHMT1 deletions cause Kleefstra syndrome (KS, OMIM #610253), characterized by severe developmental delays, intellectual disability, and autism-like behaviors, including hyperkinetic hand movements, bruxism, and self-harm. EHMT2 gene alterations are rarer but similar to KS. Diagnostics like EEG show abnormal activity, and MRI indicates brain atrophy, arachnoid cysts, and thinning of the corpus callosum. Affected individuals have poor motor skills, limited walking ability, and delayed growth and sexual development. More info