title: Fish odor syndrome (trimethylaminuria) supporting the possible FMO3 down expression in childhood: a case report.
abstract: BACKGROUND
  Trimethylaminuria is a rare inherited disorder due to decreased metabolism of dietary-derived trimethylamine by flavin-containing monooxygenase 3. Several single nucleotide polymorphisms of the flavin-containing monooxygenase 3 gene have been described and result in an enzyme with decreased or abolished functional activity for trimethylamine N-oxygenation thus leading to trimethylaminuria.
  
  
  METHODS
  Here we investigated an Italian family in which the proband was a 7-year-old girl with suspected trimethylaminuria, by flavin-containing monooxygenase 3 gene direct sequencing and urinary determination of trimethylamine and trimethylamine N-oxide. Genetic analysis found that, as with her parents and one of her two brothers, the proband carried three polymorphisms: c.472 G>A p. E158K (rs 2266782) in exon 4, c.627+10 C>G (IVS5+10G>C) (rs 2066534) and c.485-21 G>A (IVS4-22G>A) (rs 1920149) in intronic regions.
  
  
  CONCLUSIONS
  Despite the same genotypic condition only the girl had symptoms attributable to the trimethylaminuria. The suspicion is that she has transient childhood trimethylaminuria. Therefore, we bring attention to the importance of genetic testing and eventual determination of urinary trimethylamine and trimethylamine N-oxide as instruments to offer to clinicians in the management of these pediatric patients.
authors.forename: Rosalia
authors.initials: R
authors.lastname: D'Angelo
authors.forename: Concetta
authors.initials: C
authors.lastname: Scimone
authors.forename: Teresa
authors.initials: T
authors.lastname: Esposito
authors.forename: Daniele
authors.initials: D
authors.lastname: Bruschetta
authors.forename: Carmela
authors.initials: C
authors.lastname: Rinaldi
authors.forename: Alessia
authors.initials: A
authors.lastname: Ruggeri
authors.forename: Antonina
authors.initials: A
authors.lastname: Sidoti
mesh_terms: D015415:Biomarkers / Q000652:urine; D002648:Child; D015536:Down-Regulation; D005260:Female; D005819:Genetic Markers; D006801:Humans; D008661:Metabolism, Inborn Errors / Q000175:diagnosis* / Q000235:genetics / Q000652:urine; D008744:Methylamines / Q000652:urine*; D010105:Oxygenases / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide
chemical_list: D015415:Biomarkers; D005819:Genetic Markers; D008744:Methylamines; D010105:Oxygenases; C020066:dimethylaniline monooxygenase (N-oxide forming); C005855:trimethyloxamine; C023336:trimethylamine