Fish-Odor Syndrome (Trimethylaminuria)

You may have chanced upon someone who smelt of rotten fish and you might have felt hugely repelled. It might surprise you to know that the disgustful odor might also be due to an uncommon genetic syndrome, clinically known as trimethylaminuria and commonly known as “fish –odor syndrome.”

There are many who suffer the ignominy of strong and overwhelming body odor. Most of these people have been treated like social outcasts. Food habits of these people, and their poor hygiene, have been often blamed for this unfortunate trait. All this has a severely negative psychological impact on the suffering individual.

But recently a study has revealed that in some people with excessive unexplained body odor, an uncommon genetic disorder--"fish-odor syndrome"-- may be the culprit.

Clinically known as trimethylaminuria, this metabolic disorder is a condition that is characterized by the sufferer emitting excessive amounts of the compound trimethylamine (TMA), which is normally produced during the digestion of choline-rich foods.

Irony is that people with TMA spontaneously produce bad odors despite maintaining optimal hygiene. TMA has a distinct fish odor but only about 10 to 15 percent of people with trimethylaminuria emit the characteristic odor and this makes the condition very difficult to diagnose.

Paul Wise, of Monell Chemical Senses Center in Philadelphia headed the study which has been published recently in the American Journal of Medicine.

Trimethylaminuria is caused by a mutation in the gene FMO3 and results in an inability in the body to metabolize Trimethylamine and reduce it to odor-free compounds.

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A person with this condition would have inherited one copy of the deleterious gene from each of his parent. The parents usually carry a single copy of this mutant gene; they do not suffer from body odor but are ‘carriers’ of this gene.

The current study was undertaken by Wise and his colleagues to estimate the frequency with which trimethylaminuria was diagnosed in individuals who sought help for unexplained, troublesome and chronic body odor. Tests were carried out by measuring the levels of the “smelly” chemical, in the urine, after an individual drank a choline-containing beverage.

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Of the 118 patients who tested positive for TMA only 3.5 percent had complained of the charecteristic "fishy" odor although they reported general body odor, bad breath or foul taste in the mouth far more often. The vast majority of the patients had earlier consulted several doctors and dentists before they were referred to Monell.

Many of the patients in the study had seen several doctors and dentists before being referred to Monell for testing. There are not many labs that do TMA testing—just a few across United States.

Currently there is no reliable method to treat TMA. The only known method would be to alter the food one eats and minimize choline – rich foods. Meat and sea foods are rich source of choline rich foods and avoiding these and other such food can help to decrease the body odor.

Food to be avoided or cut down include the following:

• Saltwater fish
• Eggs
• Liver
• Legumes such as kidney beans or soya
• Brussel sprouts
• Broccoli
• Sun-dried tomatoes
• Mustard seed
• Coriander leaf
• Dried parsley
• Dried coriander leaf
• Garlic
• Chili powder
• Chocolate

Source-Medindia