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Unit Code 9254:
Vanillylmandelic Acid (VMA) and Homovanillic Acid (HVA), Pediatric, Urine

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Useful For

Children, when a 24-hour collection is problematic

 

Screening for catecholamine-secreting tumors in children

 

Supporting a diagnosis of neuroblastoma

 

Monitoring neuroblastoma treatment

Clinical Information

Diagnosis of many inborn errors of serotonin and catecholamine

metabolism can be supported biochemically by the

quantification of neurotransmitters and their metabolites in

physiologic fluids. For example, dopamine beta-hydrolase (DBH)

deficiency and monoamine oxidase-A (MAO-A) deficiency can cause

elevated and decreased urinary homovanillic acid (HVA), respectively.

 

The biochemical diagnosis of catecholamine-secreting tumors

(eg, neuroblastoma) relies on the determination of several metabolites

including HVA and vanillylmandelic acid (VMA), which are also useful

in monitoring treated patients.

Reference Values

VMA

      <1 year: <27.0 ug/mg Cr

      >=1 year: <18.0 ug/mg Cr

      2-4 years: <13.0 ug/mg Cr

      5-9 years: <8.5 ug/mg Cr

      10-14 years: <7.0 ug/mg Cr

      >=15 years: not applicable

 

HVA

      <1 year: <35 ug/mg Cr

      >=1 year: <23 ug/mg Cr

      2-4 years: <13.5 ug/mg Cr

      5-9 years: <9 ug/mg Cr

      10-14 years: <12 ug/mg Cr

      >=15 years: not applicable

Interpretation

Increased values are seen in neuroblastoma.

Cautions

All patients receiving L-dopa should be identified to the

laboratory when VMA and HVA tests are ordered.

 

VMA excretion may be normal in individuals with pheochromocytoma.

Recommended tests for this purpose are #81609 "Metanephrines,

Fractionated, Free, Plasma"; #83006 "Metanephrines, Fractionated,

24 Hour, Urine"; and #9276 "Catecholamine Fractionation,

Urinary, Free."

Clinical Reference

1.   Hyland K, Biaggioni I, Elpeleg ON, et al:  Disorders of neurotransmitter

      metabolism.  In Physician's Guide to the Laboratory Diagnosis

      of Metabolic Disease. Edited by N Blau, M Duran, M E Blaskovics.

      London UK, Chapman and Hall Medical, 1996, pp 79-98

 

2.   Gitlow SE, Bertani LM, Rausen A, et al:  Diagnosis of neuroblastoma

      by qualitative and quantitative determination of catecholamine

      metabolites in urine.  Cancer 1970;25:1377-1383

Key