title: A nonsense mutation in the FMO3 gene underlies fishy off-flavor in cow's milk.
abstract: Fish-odor syndrome or Trimethylaminuria (OMIM #602079) in humans is an inborn error of metabolism associated with a characteristic fishy body odor due to elevated levels of trimethylamine (TMA) in body fluids. It is caused by loss-of-function mutations in FMO3 encoding flavin-containing mono-oxygenase 3. A fishy off-flavor is occasionally observed in cow's milk and it has been established recently that this phenotype is due to elevated TMA levels. Here, we report that fishy off-flavor in cow's milk is caused by a nonsense mutation (R238X) in the bovine FMO3 ortholog. RT-PCR analysis indicated that the mutant transcript is present in a very low amount. The mutation was found to be surprisingly common (q = 0.155) in one breed of cattle.
authors.affiliation: Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: Anne
authors.initials: A
authors.lastname: Lundén
authors.forename: Stefan
authors.initials: S
authors.lastname: Marklund
authors.forename: Victoria
authors.initials: V
authors.lastname: Gustafsson
authors.forename: Leif
authors.initials: L
authors.lastname: Andersson
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D001120:Arginine / Q000235:genetics; D002417:Cattle; D018389:Codon, Nonsense / Q000235:genetics*; D005091:Exons / Q000235:genetics; D005260:Female; D006580:Genetic Carrier Screening; D006720:Homozygote; D006801:Humans; D008297:Male; D008661:Metabolism, Inborn Errors / Q000235:genetics; D008744:Methylamines / Q000378:metabolism; D008892:Milk / Q000737:chemistry* / Q000201:enzymology; D008969:Molecular Sequence Data; D010105:Oxygenases / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013649:Taste / Q000235:genetics
chemical_list: D018389:Codon, Nonsense; D008744:Methylamines; D001120:Arginine; D010105:Oxygenases; C020066:dimethylaniline monooxygenase (N-oxide forming); C023336:trimethylamine