skip navigation

Test Identifier Information

Registration CodeMPST

All 9 coding exons and upstream elements 1 and 2 of the Flavin-containing monooxygenase 3 gene (FMO3) are amplified by PCR and sequenced by DNA sequencing.


Diagnostic Use / Indications

Primary FMO3 deficiency, an inborn error of choline metabolism, leads to an accumulation of trimethylamine, which because of its associated pungent odour of rotting fish, is a socially crippling disorder. Onset is generally in early childhood, but it may take years before the diagnosis is established. The disorder is inherited as an autosomal recessive trait as a consequence of mutations in the FMO3 gene. At least 20 different disease-causing mutations have been identified. The incidence of TMAU due to FMO3 deficiency is not precisely known, but may range from 1 in 100 to 1 in 1000 individuals. Management of this disorder is primarily dietary.

External Price$0.00(Exclusive of GST)

Specimen Collection

Patient Specimen4.0mL EDTA (Lavendar) blood
Paediatric Specimen0.5 mL - 1 mL EDTA (Lavendar) blood
Sample Delivery to LabAmbient

CHLabs Laboratory

DepartmentBiochemistry - Molecular Pathology
Contact Details Email Email
This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
Contact Phone Number03 3640 548
Test Availability9.00 am to 5.00 pm, Monday to Friday
Turnaround TimeWithin 4 weeks
Uncertainty of Measurement

Automated bidirectional DNA sequencing has an analytical sensitivity and specificity of >99%. Note that the lower limit of variant detection of sequencing analysis is ~10%, this is important to consider in the case of mosaicism, mitochondrial, and somatic variation that is not expected to be present at 50% or 100%.  This analysis will not detect variants located within intronic regions, except at the intron-exon boundaries.

Additional Information
  1. This test requires nucleated cells. Please do not centrifuge or freeze blood samples.
  2. Genomic DNA must be extracted from the specimen prior to testing. This incurs an additional charge (see GDNA). Laboratories may prefer to submit DNA for testing. Please provide a minimum of 5 micrograms of DNA at 20 nanograms/microlitre.
  3. If storing blood tube prior to delivery please refrigerate at 4 degrees (transport still at ambient temperature).

CHL Follow us on Facebook