AsseyMethod: spectrophotometric
Abbrevation: VMA
Sector: Microbiology
SampleType: U
S.Vol: 10
Transport: at 2-8˚c, -20˚c
Storage: 2 weeks at 2-8˚c with pH: 2-4
Test Name: Vanillylmandelic Acid and Catecholamines
Normal Range: <13.6
To help diagnose or rule out a neuroblastoma and to monitor the effectiveness of treatment
When your child has symptoms consistent with neuroblastoma
A 24-hour urine sample is preferred; sometimes a random urine sample is acceptable
Though the test is affected by caffeine and certain drugs this is not usually relevant in children.
Vanillylmandelic acid (VMA) is one of the metabolites of the catecholamines adrenaline (epinephrine) and noradrenaline (norepinephrine), hormones produced in the adrenal glands. This test measures the amount of VMA that is excreted into the urine, typically over a 24-hour period, to detect excess catecholamine production.
Neuroblastomas can produce large amounts of catecholamines resulting in greatly increased concentrations of the hormones and their metabolites.Neuroblastomas are the second most common solid tumour in childhood after brain cancer. Up to 90 per cent of cases occur in children under the age of five. Once detected, many neuroblastomas can be successfully treated.
How is the sample collected for testing?
For a 24-hour urine collection, all of the urine produced during a 24-hour period should be collected into a container and saved. It is important that the sample be refrigerated during this time period. A single urine sample is collected for a random urine test.
Is any test preparation needed to ensure the quality of the sample?
This test is affected by caffeine, certain drugs, and stresses. Though this is less likely in children it is important to inform your healthcare professional of any medications being given, including herbal supplements and over-the-counter products, and to follow any instructions provided for things to withhold before sample collection.