Familial Mediterranean Fever Gene Testing
(Mendelian Inheritance in Man # 249100)
Test Information/Clinical Significance
FMF usually presents prior to adult life. Patients may experience intermittent attacks of fever and serosal inflammation affecting the abdomen or chest. Joint pain and laboratory markers of inflammation are common. Many patients may develop AA-amyloidosis and most patients respond to therapy with colchicine.
Occasionally, patients with periodic fever may have mutations in other proteins resulting in periodic Hibernian fever (also known as TRAPS or Tumour necrosis factor Receptor Alpha Polymorphism Syndrome); the Muckle-Wells Syndrome or Familial Cold Urticaria Syndrome.
The test is useful for the confirmation of the diagnosis of FMF in patients with relevant clinical features. The test may also be useful in differentiating causes of periodic fever, in genetic counselling and in prenatal diagnosis.
Genetic counselling
Genetic counselling is an essential aspect of testing for all genetic disorders and should be offered to patients prior to referral for testing and for discussion of test results.
Specimen Collection
The required specimen is a dedicated 5 mL EDTA (purple-top) tube. Collection may be performed through any Douglass Hanly Moir Pathology collection centre. The pathology request form should state “FMF Gene Mutation”.
Assay Method
The testing, which is performed in the Sonic Clinical Institute located at Douglass Hanly Moir Pathology at Macquarie Park, involves bi-directional sequencing of exon 2 and exon 10. This strategy detects more than 95% of the mutations reported in patients with FMF. Some patients with FMF may have mutations in other genes as well as in other exons of the MEFV gene. Additional sequencing of the MEFV gene is available after consultation.
Results
The assay is performed weekly with a usual turnaround time of two weeks or less. We report the presence or absence of any mutations and provide an interpretation based on the clinical information supplied, as well as the limitations of the test for diagnosis.