NR1I3 and Kleefstra syndrome: In a cohort of patients with Kleefstra-syndrome-like appearance but no EHMT1 mutations, next-generation sequencing approaches revealed single de novo mutations in five novel candidate genes (MBD5, SMARCB1, KMT2C, NR1I3 and MTMR9) in four patients (Kleefstra et al., 2012).