The flavin-containing monooxygenases are NADPH-dependent enzymes that catalyze the oxidation of many drugs and xenobiotics. In most mammals, there is a flavin-containing monooxygenase that catalyzes the N-oxidation of some primary alkylamines through an N-hydroxylamine intermediate. However, in some human populations, this enzyme is truncated and likely degraded rapidly. The protein encoded by this gene represents the truncated form and apparently has no catalytic activity. A functional allele found in African Americans has been reported, but no sequence evidence has been deposited to support the finding. This gene is found in a cluster with the FMO1, FMO3, and FMO4 genes on chromosome 1. [provided by RefSeq, Jun 2013]