Form Downloads:

Consent Form
Data Collection Form
Protocol
Subject Information Sheet

*If you think you, or someone you know, may have TMAU, please read this ENTIRE page. Everything you need to know regarding HBRI and it's procedures for TMAU testing can be found on this page.

What is TMAU?

Trimethylaminuria (TMAU) is a genetically-mediated disorder, which appears to be inherited in an autosomal, recessive fashion. This was discovered initially by studying sufferers and their families, and more recently, by examining the molecular deficits responsible for TMAU. The biochemical deficit causing TMAU is the inability to completely metabolize trimethylamine (TMA) to TMA-oxide (TMAO) in the liver. TMAO is a non-volatile (non-odorous) solid that is excreted in urine. The enzymes catalyzing this conversion are the microsomal, flavin-containing monooxygenase (FMO). The FMO family of enzymes are catalytically diverse and catalyze the oxygenation of a variety of heteroatom-containing (N-, S-, P-) endogenous and xenobiotic compounds.

The principle presenting symptoms of TMAU stem from excess, unmetabolized trimethylamine. TMA is formed in the gut by bacterial metabolism of dietary constituents, principally choline. TMA is a gas at body temperature and has a foul, fishy odor. At very low concentration, it may only be perceived as foul, unpleasant or “garbage-like”. Excessive production of TMA is linked to the intake of a variety of choline rich foods, (such as eggs, certain legumes, fish and organ-meats) hence the sporadic production of symptoms. Because there are many foods that are rich in choline, both patients and their family members are unlikely to relate the odor to food intake.

Symptoms may include foul body odors, halitosis and/or dysguesia, which can produce social embarrassment and can be temporarily relieved by normal hygiene procedures. Further, the unpleasant symptoms are often sporadic in occurrence and seemingly subjective, and when coupled with a lack of knowledge of the disease and its etiology among health professionals, may lead to diagnosis of poor hygiene, psychiatric problems, and/or referrals to other specialists. The latter has been financially draining many patients.

Several reports in the literature have described other complications occurring in conjunction with TMAU, such as seizures, skin rashes and syndromes (Prader-Willi, and Noonan’s). However, the vast majority of patients appear to have normal mental and physical abilities, lead normal lives and have good hygiene practices. The main problem afflicting most patients are psycho-social ones cause by sporadic, unexplained odor production.

The First Step is Getting a Diagnosis!

HBRI is a non-profit research institute and one of the only laboratories in the US that offers high-precision phenotyping (urine test) and genotyping (blood test) studies to patients. We do not run a service center, but do ask for donations to partially offset the expenses of doing the assays. Please include $400 for the phenotyping test (urine) and/or $400 for the genotyping test (blood) with your sample(s). The actual cost of doing these assays for the institute is closer to $1,500, so your donations are extremely important. Your contribution will be treated as a donation to our TMAU (trimethylaminuria) research program. Unfortunately we cannot accept any insurance plans.

The Genotype test will tell you if you have a genetic mutation that has been associated with TMAU.

The Phenotype test will tell you if have an excess amount TMA in your urine.

You can choose to have either test performed or both.

How Do I Get Tested?

We are not a clinical lab and do not see patients, so your samples will need to be mailed to our institute for testing.

1. Please download, print and review the forms available on our site: Consent Form, Data Collection Form, Subject Information Sheet and Protocol.

2. Collect your samples.

For the phenotyping (urine) test you can either visit your physician and have him/her take the sample or we can send you a urine tube and you can take the sample yourself. The urine sample will need to be frozen and shipped overnight on dry ice, in an insulated container (styrofoam works well). Please follow the guidlines on the General Protocol Sheet when collecting and shipping your sample.

For the genotyping (blood) test you will need to have your blood drawn. Your physician or a lab should be able to do that. You will most likely need to supply all of the necessary shipping materials, but please check with the lab first. The blood sample will need to stay cool. Ship the sample overnight on wet ice (ice packs), in an insulated container (styrofoam works well). Please follow the guidlines on the General Protocol Sheet when collecting and shipping your sample.

3. Complete the Consent Form (signed), Data Collection Form and Subject Information Sheet and send along with your check in a ziplock baggy and your sample.

4. Phone the institute when your sample(s) has been shipped so that we can know to expect it. We will notify you via email or phone once the sample has been received.

After reveiwing the information. Individuals who are interested in being tested for TMAU may phone the institute for further instructions or clarifications. For more information please call (858) 458-9305 or email rhandley@hbri.org

Testing may take up to 12 weeks and sometimes longer, so please be patient.

More Information on TMAU.

Visit the National Institutes of Health, Office of Rare Diseases' website for more information and links regarding TMAU.

Visit the USDA's website for USDA's Database for the Choline Content
of Common Foods

Click here to read the abstract from a recent article on TMAU co-authored by HBRI's Director, Dr. Cashman.