New trimethylaminuria paper by Preti, Fennessey et al

Individuals Reporting Idiopathic Malodor Production: Demographics and Incidence of Trimethylaminuria.
Wise PM, Eades J, Tjoa S, Fennessey PV, Preti G.

Monell Chemical Senses Center, Philadelphia, Pa.

Abstract
BACKGROUND:
Individuals with the metabolic disorder trimethylaminuria may sporadically produce malodors despite good hygiene. The psychosocial impact of trimethylaminuria can be considerable. However, trimethylaminuria is difficult to diagnose without specialized tests, in part because odor production is diet-dependent and malodors may not be present during medical examinations. Thus, the prevalence and demographics of trimethylaminuria remain unclear.

METHODS:
We tested 353 patients who had unexplained (idiopathic) malodor production for trimethylaminuria using a standard choline challenge. We also collected basic demographic information.

RESULTS:
Approximately one third of patients (118) tested positive for trimethylaminuria. Consistent with previous reports, women, particularly African American women, were significantly overrepresented among trimethylaminuria-positive patients. Of note, the same pattern was seen among trimethylaminuria-negative patients. Also consistent with previous reports, trimethylaminuria-positive women who were still menstruating tended to produce higher levels of trimethylamine within ±7 days of menses, although this trend was statistically marginal (P = .07).

CONCLUSION:
If our patient sample is representative of patients with idiopathic malodor, demographic information (race and gender) may not be useful in a differential diagnosis of trimethylaminuria. However, undiagnosed cases of trimethylaminuria may be fairly common among patients with idiopathic malodor. If so, choline challenge testing should be indicated for all such patients because trimethylaminuria is responsive to dietary and other treatments. We speculate that testing also might reveal cases of trimethylaminuria among those diagnosed with certain psychologic disorders, including olfactory reference syndrome.

This is the abstract of a new paper on trimethylaminuria (TMAU) published ahead of print of the full paper. It could be a paper unfinished from a while ago, since it includes Susan Tjoa as an author, who sadly passed away a few years ago now.

It sounds a very useful paper as evidence for the case of testing most people with a long-time suspected malodor problem, including those diagnosed with the recently defined psychiatric 'disorder' known as 'olfactory reference syndrome'.

Of interest is :
The number of people who 'failed' the test (about 1/3). This was probably under the 'Denver TMAU test reference ranges', which does not seem to regard TMA level alone as significant (and hence is very unlikely to find anyone positive for 'TMA substrate overload' (the most common type of TMAU2).

A large number of the positive cases were women and especially African American women. This seems to be a reflection of the community, although perhaps women are more likely to test. Nevertheless, women of African American descent seem to be over-represented in the community.

They suggest it may be worthwhile testing those diagnosed with 'olfactory reference syndrome' for TMAU. This has been a MEBO Research suggestion for a while now. It would make an excellent study and possibly mark the end of 'ORS'.

They used a choline challange for the test. It would be interesting to have seen the test done using the 'TMAU carrier test' protoco', which involved taking 600mg TMA in a capsule. Normal people would still be able to process almost all of 600mg of TMA, but those with 'no reserve capacity' (probably all 'carriers') would likely show up along with 'sufferers'.

So, all in all, it sounds like an excellent paper as evidence about the prevalence of TMAU using the traditional TMAU testing methods and protocol followed by the Denver lab which has a long association with TMAU.