Endocrine Abstracts

Introduction: Trimethylaminuria or Fish Odour syndrome is a rare genetic metabolic disorder. It can cause significant suffering to affected individuals due to social isolation and stigma. It is under recognised and ignored.

The case: A 60 years old lady was referred by her GP. The referral – ‘She feels she has a problem with personal hygiene and is aware of an odour from her skin, her breath and urine.’ This lady has been suffering from this condition almost as long as she can care to remember. She has spent nearly all her money on toiletries and deodorants. Because the problem was so bad, she has had to isolate herself from her near and dear ones, from friends. Consequently, she has been suffering from depression. Her other medical condition included hypertension. Her father, she said, also had problems of malodour very similar to her. She has accepted this as part of her existence until she came across an article in one of newspaper about the existence of this condition. She went to her GP, and was referred. Clinical examination did not reveal any significant abnormality. On the day of her clinic visit, she did apply significant amount of deodorants to mask the odour.

Results: Twenty four hour urine for Trimethylamine (TMA), TMA-n-oxide, TMA/TMA-n-oxide; Trimethylamine (TMA) – 77.6 μmol/mmol creat (2.5–10.8); TMA-n-oxide 91.6 μmol/mmol creat (17.0–147.0); TMA/TMA-n-Oxide 0.85. These results are compatible with Primary or Secondary Trimethylaminuria. Primary Trimethylaminuria – a deficiency of hepatic TMA oxidation. Secondary Trimethylaminuria–enterobacterial overgrowth.

Discussion: Based on above, it appears that this lady has been suffering from Trimethylaminuria. Given the family history, it is most likely primary. The differentiation from primary and secondary could be done by DNA mutation analysis (TMAU1/FMO3 gene test). This condition is largely under recognised and has contributed to this lady’s suffering for a long time. Treatment: She has been treated with 2 weeks of amoxicillin.