Yang D, Chen J, Cheng X, et al. - Despite correlation of common variants in a large collection of patients with elevated risk for bipolar disorder (BD), only 25%-45% of risks could be predicted in studies, suggesting the presence of lots of unknown variants contributing to the risk for BD. Hence, researchers sought to determine novel BD risk genes. Whole-exome sequencing was performed in 27 individuals from 6 BD multi-affected Chinese families. The association was validated by targeted sequencing of one of the novel risk genes, SERINC2, in additional sporadic 717 BD patients and 312 healthy controls (HC). Large-scale sequencing led to the identification of a novel recessive BD risk gene, SERINC2, which is identified to have a role in synthesis of sphingolipid and phosphatidylserine (PS). As per MRI image results, the homozygous nonsense variant in SERINC2 influences the volume of white matter in cerebellum.