This condition is characterised by craniofacial appearance, fixed contractures of the upper limbs, abnormal posture, feeding difficulties, intellectual disability, small size at birth and failure to thrive.

[1] Children with BOS can also have recurring respiratory infections, silent aspiration, sleep apnea, developmental delay, abnormal hair density and length, Wilms' tumors, brain abnormalities, and other issues.

[citation needed] Genetically, de novo truncating mutations in ASXL1 have been shown to account for approximately 50% of Bohring–Opitz syndrome cases.

[2][3] A second gene associated with this condition is the Kelch-like family member 7 (KLHL7).

[citation needed] The syndrome is extremely rare, with fewer than 80 reported cases worldwide.