In contrast, patients with dominant mutations of ASXL1 are diagnosed with Bohring-Opitz syndrome, a malformation syndrome characterized by severe intrauterine growth retardation, intellectual disability, trigonocephaly, hirsutism, and flexion of the elbows and wrists with a deviation of the wrists and metacarpophalangeal joints (Hoischen et al. 2011). Here, ASXL1 is linked to developmental defect during embryogenesis.