EHMT1 and Kleefstra syndrome: Haploinsufficiency of EHMT1 is the primary cause of the 9q34subtelomeric-deletion syndrome, also known as Kleefstra syndrome (Kleefstra et al.,2005, 2006), a condition associated with intellectual disabilities,epilepsy, childhood hypotonia, facial dysmorphism, microcephaly, delays inreaching developmental milestones and behavioural problems such asaggressive outbursts and hypoactivity.