Gene FMO3

Also known as

TMAU, dFMO, flavin-containing monooxygenase 3, trimethylamine monooxygenase

Overview

FMO3 (Flavin-Containing Monooxygenase 3) encodes the primary enzyme responsible for converting trimethylamine (TMA) to trimethylamine N-oxide (TMAO) in the liver. TMA is produced by gut bacteria from dietary choline, carnitine, and other nutrients found in eggs, meat, and fish. Without proper FMO3 function, TMA accumulates and is excreted in sweat, urine, and breath, causing a fish-like odor.

Severe mutations in FMO3 cause primary trimethylaminuria (TMAU, "fish odor syndrome"), a metabolic condition with significant social and psychological impact. Milder variants are common and cause transient or diet-dependent symptoms. Interestingly, research has also linked TMAO levels to cardiovascular disease risk, though the relationship is complex and FMO3's role in disease prevention versus promotion is still being studied.

Understanding your FMO3 genetic status is important for individuals experiencing unexplained body odor and for understanding personal responses to choline-rich diets. Dietary modifications limiting TMA precursors can significantly reduce symptoms in affected individuals.

NutraHacker Raw DNA Analysis Products that include this gene

• Lactation Report

Upload raw DNA data to get your very own analysis of gene FMO3 through your personalized DNA reports.