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It is possible that the main title of the report Trimethylaminuria is not the name you expected.

Disorder Subdivisions

  • None

General Discussion

Trimethylaminuria is a rare disorder in which the body's metabolic processes fail to alter the chemical trimethylamine. Trimethylamine is notable for its unpleasant smell. It is the chemical that gives rotten fish a bad smell. When the normal metabolic process fails, trimethylamine accumulates in the body, and its odor is detected in the person's sweat, urine and breath. The consequences of emitting a foul odor can be socially and psychologically damaging among adolescents and adults. The genetic or primary form of this disorder is transmitted as an autosomal recessive trait.

The metabolic deficiency occurs as a result of a failure in the cell to make a specific protein, in this case the enzyme flavin-containing monooxygenase 3. Enzymes are nature's catalysts and act to speed up biochemical processes. Without this enzyme, foods containing carnitine, choline and/or trimethylamine N-oxide are processed to trimethylamine and no further, causing a strong fishy odor. A secondary form of trimethylaminuria may result from the side effects of treatment with large doses of the amino-acid derivative L-carnitine (levocarnitine) or choline. This secondary form of the disorder is a result of an overload of trimethylamine. In this case, there is not enough of the enzyme to get rid of the excess trimethylamine.

Supporting Organizations

CLIMB (Children Living with Inherited Metabolic Diseases)

Climb Building
176 Nantwich Road
Crewe, CW2 6BG
United Kingdom
Tel: 4408452412173
Fax: 4408452412174

Genetic and Rare Diseases (GARD) Information Center

PO Box 8126
Gaithersburg, MD 20898-8126
Tel: (301)251-4925
Fax: (301)251-4911
Tel: (888)205-2311

MEBO Research, Inc.

13220 S.W. 35th Terrace
Miami, FL 33175-6931
Tel: (786)228-6880

For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders (NORD). For a full-text version of this report, go to and click on Rare Disease Database under "Rare Disease Information".

The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only.

It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report.

This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.

Last Updated:  6/30/2015
Copyright  2014 National Organization for Rare Disorders, Inc.