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Test ID: PUPYP Purines and Pyrimidines Panel, Plasma


Advisory Information


The preferred test to rule-out inherited disorders of purine and pyrimidine metabolism is PUPYU / Purines and Pyrimidines Panel, Urine.

 

This test does not evaluate succinyladenosine. If succinyladenosine analysis is needed, order PUPYU / Purines and Pyrimidines Panel, Urine.



Necessary Information


Patient's age is required.



Specimen Required


Collection Container/Tube: Lavender top (EDTA)

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions: Centrifuge at 4° C and aliquot plasma. Send plasma frozen.


Useful For

Evaluating patients with symptoms suspicious for disorders of purine and pyrimidine metabolism

 

Monitoring patients with disorders of purine and pyrimidine metabolism

 

Laboratory evaluation of primary and secondary hyperuricemias

 

Assessing tolerance for fluoropyrimidine drugs used in cancer treatment

 

Aiding in the diagnosis of individuals with suspected dihydropyrimidine dehydrogenase (DPD) deficiency

Method Name

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Reporting Name

Purines and Pyrimidines Panel, P

Specimen Type

Plasma

Specimen Minimum Volume

0.2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma Frozen 90 days

Clinical Information

Purines (adenine, guanine, xanthine, hypoxanthine, uric acid) and pyrimidines (uracil, thymine, cytosine, orotic acid) are involved in all biological processes, providing the basis for storage, transcription, and translation of genetic information as RNA and DNA. Purines are required by all cells for growth and survival and also play a role in signal transduction and translation. Purines and pyrimidines originate primarily from endogenous synthesis, with dietary sources playing only a minor role. The end product of purine metabolism is uric acid (2,6,8-trioxypurine), which must be excreted continuously to avoid toxic accumulation.

 

Disorders of purine and pyrimidine metabolism can involve all organ systems at any age. The diagnosis of the specific disorders of purine and pyrimidine metabolism is based upon the clinical presentation of the patient, determination of specific concentration patterns of purine and pyrimidine metabolites, and confirmatory enzyme assays and molecular genetic testing.

 

Over 35 inborn errors of purine and pyrimidine metabolism have been documented. Clinical features are dependent upon the specific disorder but represent a broad spectrum of clinical manifestations that may include immunodeficiency, developmental delay, nephropathy, and neurologic involvement. The most commonly described disorder of purine metabolism involves a deficiency of hypoxanthine-guanine phosphoribosyl transferase (HPRT), the majority of which have classic Lesch-Nyhan syndrome. Lesch-Nyhan syndrome is an X-linked disorder characterized by crystals in urine, neurologic impairment, mild to severe intellectual disability, development of self-injurious behavior, and uric acid nephropathy.

 

Treatments for Lesch-Nyhan syndrome include allopurinol, urine alkalinization and hydration for nephropathy, and supportive management of neurologic symptoms. For milder forms of HPRT deficiency, treatment that can mitigate the potentially devastating effects of these diseases are disorder dependent; therefore, early recognition through screening and subsequent confirmatory testing is highly desirable.

 

Dihydropyrimidine dehydrogenase (DPD) deficiency  can result in a severe disorder in infancy involving seizures, intellectual disability, microcephaly and hypertonia. In its mildest form however, individuals with DPD deficiency may be asymptomatic but are at risk for life-threatening toxic reactions to a certain class of drugs used to treat cancer called fluoropyrimidines (eg, 5-fluorouracil and capecitabine). If individuals with DPD deficiency ingest this medication, they can develop fluoropyrimidine toxicity. This drug toxicity can result in inflammation of the gastrointestinal tract and associated symptoms, as well as abnormal blood counts including neutropenia and thrombocytopenia.

Reference Values

Purines and Pyrimidines Pane, Plasmal

Reference Values

(all results reported as nmol/mL)

Age range

0-1 years

>1-4 years

5-18 years

>18 years

Uracil

≤2

≤2

≤2

≤2

Thymine

≤2

≤2

≤2

≤2

Adenine

≤3

≤3

≤3

≤3

Hypoxanthine

≤35

≤17

≤15

≤15

Xanthine

≤6

≤6

≤6

≤3

Dihydroorotic

≤2

≤2

≤2

≤2

Uric Acid

100-450

150-500

150-500

150-500

Deoxythymidine

≤2

≤2

≤2

≤2

Deoxyuridine

≤2

≤2

≤2

≤2

Uridine

≤14

≤9

≤9

≤9

Deoxyinosine

≤2

≤2

≤2

≤2

Deoxyguanosine

≤2

≤2

≤2

≤2

Inosine

≤2

≤2

≤2

≤2

Guanosine

≤2

≤2

≤2

≤2

Dihydrouracil

≤3

≤3

≤3

≤3

Dihydrothymine

≤2

≤2

≤2

≤2

N-carbamoyl- beta-alanine

≤2

≤2

≤2

≤2

N-carbamoyl- beta-aminoisobutryic acid

≤2

≤2

≤2

≤2

Interpretation

Abnormal concentrations of measurable compounds will be reported along with an interpretation. The interpretation of an abnormal metabolite pattern includes an overview of the results and of their significance, a correlation to available clinical information, possible differential diagnosis, recommendations for additional biochemical testing and confirmatory studies (enzyme assay, molecular analysis), name, and phone number of contacts who may provide these studies, and a phone number of the laboratory directors in case the referring physician has additional questions.

Clinical Reference

1. Jinnah HA, Friedmann T: Lesch-Nyhan Disease and Its Variants. In The Online Metabolic and Molecular Bases of Inherited Disease. Edited by D Valle, AL Beaudet, B Vogelstein, et al. New York, NY. McGraw-Hill 2014. Accessed April 23, 2019. Available at http://ommbid.mhmedical.com/content.aspx?bookid=971&sectionid=62635320

2. Balasubramaniam S, Duley JA, Christodoulou J: Inborn errors of purine metabolism: clinical update and therapies. J Inherit Metab Dis 2014;37:669-686

3. Balasubramaniam S, Duley JA, Christodoulou J: Inborn errors of pyrimidine metabolism: clinical update and therapy. J Inherit Metab Dis 2014;37:687-698

Day(s) and Time(s) Performed

Tuesday; 8 a.m.

Analytic Time

7 days (not reported on Saturday or Sunday)

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

82542

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PUPYP Purines and Pyrimidines Panel, P 79665-6

 

Result ID Test Result Name Result LOINC Value
92310 Interpretation (PUPYP) 79659-9
92292 Uracil 75152-9
92293 Thymine 75121-4
606842 Adenine 75131-3
92294 Hypoxanthine 75135-4
92295 Xanthine 75144-6
92296 Dihydroorotic 79654-0
92297 Uric Acid 14933-6
92298 Deoxythymidine 48162-2
92299 Deoxyuridine 47957-6
92300 Uridine 75159-4
92301 Deoxyinosine 75127-1
92302 Deoxyguanosine 75134-7
92303 Inosine 75150-3
92304 Guanosine 79670-6
92305 Dihydrouracil 79682-1
92306 Dihydrothymine 79669-8
92307 N-carbamoyl-B-alanine 79656-5
92308 N-carbamoyl-B-aminoisobutyric acid 79582-3
92309 Reviewed By 18771-6

Testing Algorithm

See Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm in Special Instruction.

Forms

If not ordering electronically, complete, print, and send an Inborn Errors of Metabolism Test Request (T798) with the specimen. 

Mayo Clinic Laboratories | Genetics and Pharmacogenomics Catalog Additional Information:

mml-biochemical