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Mayo #81420 Purine and Pyrimidine
Test Code81420
Alias/See Also
"5-hydroxymethyluracil
Adenine
Adenosine
Deoxyadenosine
Deoxyguanosine
Deoxyinosine
Guanosine
Hyperuricemias
Hypoxanthine
Inosine
Orotic Acid
Pyrimidine
Succinyladenosine
Thymidine
Thymine
Uracil
Uric Acid
Uridine
Xanthine
"
Adenine
Adenosine
Deoxyadenosine
Deoxyguanosine
Deoxyinosine
Guanosine
Hyperuricemias
Hypoxanthine
Inosine
Orotic Acid
Pyrimidine
Succinyladenosine
Thymidine
Thymine
Uracil
Uric Acid
Uridine
Xanthine
"
CPT Codes
83789
Preferred Specimen
Urine 3 mL
Minimum Volume
1 mL
Instructions
Collect a random urine specimen
Transport Container
Plastic, 10-mL urine tube
Specimen Stability
Frozen 7 days
Methodology
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) Diluted, filtered urine is added to an internal standard mixture and analyzed for uracil, uric acid, xanthine, and hypoxanthine by liquid chromatography tandem mass spectrometry (LC-MS/MS). LC-MS/MS is performed using a mobile phase composed of 50-mM ammonium formate, pH=5, and 1:1 mixture of 50-mM ammonium formate, pH=5:methanol, and run using a gradient. An Xterra C18 column (2.1 x 150 mm) is used to separate xanthine and hypoxanthine from the bulk of the specimen matrix. The MS/MS is operated in the selected reaction monitoring (SRM) scanning mode. The ratios of the extracted peak areas of xanthine and hypoxanthine to an internal standard are used to calculate the concentration of xanthine and hypoxanthine present.(Ito T, Van Kuilenburg AP, Bootsma AH, et al: Rapid screening of high-risk patients for disorders of purine and pyrimidine metabolism using HPLC-electrospray tandem mass spectrometry of liquid urine or urine-soaked filter paper strips. Clin Chem 2000;46:445-452)
Setup Schedule
Tuesday; 8 a.m
Report Available
7-14 days (Not reported on Saturday or Sunday) Retained for 6 months
Clinical Significance
"Urine Frozen 7 days
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
Genetics Test Information
Clinical Information
Purines (adenine, guanine, xanthine, hypoxanthine) 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/or molecular genetic testing.
There are numerous inborn errors of purine and pyrimidine metabolism that 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 involves a deficiency of hypoxanthine phosphoribosyl transferase (HPRT), the majority of which have classic Lesch-Nyhan syndrome. Lesch-Nyhan syndrome was described in 1964 as the first disorder of purine metabolism. It is an X-linked disorder characterized by severe neurologic impairment, the development of a compulsive self-destructive behavior, and uric acid nephropathy.
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 at the Mayo Clinic or elsewhere, and a phone number of the laboratory directors in case the referring physician has additional questions.
Cautions
Additional confirmatory testing is required for follow-up of abnormal results
"
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
Genetics Test Information
Clinical Information
Purines (adenine, guanine, xanthine, hypoxanthine) 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/or molecular genetic testing.
There are numerous inborn errors of purine and pyrimidine metabolism that 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 involves a deficiency of hypoxanthine phosphoribosyl transferase (HPRT), the majority of which have classic Lesch-Nyhan syndrome. Lesch-Nyhan syndrome was described in 1964 as the first disorder of purine metabolism. It is an X-linked disorder characterized by severe neurologic impairment, the development of a compulsive self-destructive behavior, and uric acid nephropathy.
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 at the Mayo Clinic or elsewhere, and a phone number of the laboratory directors in case the referring physician has additional questions.
Cautions
Additional confirmatory testing is required for follow-up of abnormal results
"
