Novel truncating mutations in ASXL1 identified in two Chinese boys with Bohring-Opitz syndrome

ABSTRACT Bohring-Opitz syndrome (BOS, or BOPS) is a rare congenital genetic disorder with multisystem abnormalities characterized by significant craniofacial dysmorphism, feeding difficulties, severe developmental delay, profound intellectual disability, flexion of elbows with ulnar deviation, and flexion of the wrists and metacarpophalangeal joints. Here, we report two Chinese BOS patients with distinctive phenotypes caused by novel truncating mutations. One was a boy aged 5 years 9 months who had a novel c.1049G>A/p.Trp350* mutation in ASXL1 and who displayed relatively mild BOS symptoms with autism features. The other was a 16-month-old boy who carried a novel c.2689delC/p.His897Ilefs*11 mutation and displayed typical BOS symptoms. New cases with novel mutations, along with a detailed clinical and molecular analysis are important to a better diagnosis and understanding of BOS.