Causes of SOC or trimethylaminuria

Body Odor Syndrome (SOC or trimethylaminuria) is caused by an excessive release of trimethylamine compounds (TMA) from the body. TMA is a natural product derived from the digestion of foods rich in choline, such as saltwater fish, egg yolks, legumes, soybeans or peas. TMA is normally metabolized by a specific enzyme called flavin, which has monooxygenase 3 (FMO3). Researchers have discovered that individuals suffering from SOC have a genetic mutation that prompts defective enzyme production, unable to properly metabolize TMA.

There is currently no treatment available for this condition, although antibiotics (which can only be taken intermittently) and a change in diet may help reduce symptoms.

Everyone has two copies of the FMO3 gene, each inherited from each parent. The disorder appears when both copies are defective. It usually appears after birth, mothers find that the affected child "smells a little funny" and try to bathe the child several times a day, although it can also appear later.

Although it was first described in 1970 , only 30 cases have been reported in the world literature and the phenotype has not yet been well defined or described. Affected individuals may present symptoms in childhood, or later in adolescence or puberty, and these appear with very different variability of expression and acuity between populations. Some patients have no symptoms until adulthood.

In sum, there is a severe stigma associated with this disease, which includes dermatological problems and a wide range of neurological symptoms. On the other hand, trimethylaminuria has been seen in Noonan and Turner syndromes, in Prader-Willi syndrome, in kidney and liver disorders, carnitine and choline disorders, hematological abnormalities and N-nicotinic deficiency, oxidation, among other diseases. The true incidence and prevalence have been impossible to assess accurately so far.

The determination of trimethylaminuria in all its forms and manifestations is not easy. Some individuals are able to control their disease through diet. There are still others that even with diet do not respond. Antibiotic treatment has been used with some patients. As several organ systems are often involved, the prevention and treatment of the full range of associated symptoms and their treatments can be complex, and are not as yet clearly delimited or resolved.

This rare disease causes excretion of relatively high amounts of TMA in urine, sweat, and breath, and has a characteristic fishy body odor from the malodor of the released amine, giving rise to the SOC designation. SOC affects one in 25,000 in England. The incidence can vary according to the population, for example in Ecuador and Guinea New Papua, they have a higher rate of this condition.

The authors draw attention to the fact that the discovery of the genetic origin of the disease does not offer an immediate cure for it, but it does offer hope for genetic or enzyme-based therapy for the future. At present, some sufferers of this disease may be helped by restricting choline-rich foods in their diet.

Unfortunately for many with SOC, this type of treatment does not seem to help. Knowing that the disease has a genetic basis and is not a matter of personal hygiene may provide a small degree of comfort to those affected.