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Adenosine deaminase enzymatic activity
Clinical Genetic Test
Help
offered by
Purine Metabolic and Immunodeficiency Lab
GTR Test Accession: Help GTR000508808.2
IMMUNOLOGYINHERITED DISEASEMETABOLIC DISEASE ... View more
Last updated in GTR: 2024-02-28
View version history
Last annual review date for the lab: 2024-02-28 LinkOut
At a Glance
Test purpose: Help
Diagnosis; Monitoring
Conditions (3): Help
Severe combined immunodeficiency, autosomal recessive, T cell-negative, B cell-negative, NK cell-negative, due to adenosine deaminase deficiency; Combined immunodeficiency; Severe combined immunodeficiency disease
Enzymes (1): Help
Adenosine deaminase
Methods (2): Help
Biochemical Genetics - Analyte: High-performance liquid chromatography (HPLC); ...
Target population: Help
patients suspected or known to have combined immune deficiency
Clinical validity: Help
Approximately 15% of patients with Severe Combined Immune Deficiency are …
Clinical utility: Help
Establish or confirm diagnosis; Guidance for management
Ordering Information
Offered by: Help
Purine Metabolic and Immunodeficiency Lab
Test short name: Help
ADA activity
Specimen Source: Help
  • Dried blood spot (DBS) card
  • Fibroblasts
  • frozen washed, packed erythrocytes
  • Peripheral (whole) blood
  • White blood cell prep
  • View specimen requirements
Who can order: Help
  • Health Care Provider
Test Order Code: Help
Not applicable
Contact Policy: Help
Laboratory can only accept contact from health care providers. Patients/families are encouraged to discuss genetic testing options with their health care provider.
How to Order: Help
contact Lab Directors or Dr. Bali by phone or email prior to sending a sample for instructions on sample preparation
Test service: Help
Biochemical testing, metabolite analysis, genotype analysis (for
Test development: Help
Test developed by laboratory (no manufacturer test name)
Informed consent required: Help
Decline to answer
Test strategy: Help
Measurement of ADA enzyme activity in erythrocytes or dried blood spots is accompanied by measurement of total adenosine and deoxyadenosine nucleotides (AXP, dAXP respectively) in extracts of erythrocytes or dried blood spots. Results of both the enzyme activity and nucleotide levels is reported. In the case of patients found to … View more
View citations (2)
Pre-test genetic counseling required: Help
Decline to answer
Post-test genetic counseling required: Help
Decline to answer
Recommended fields not provided:
Lab contact for this test
Conditions Help
Total conditions: 3
Condition/Phenotype Identifier
Test Targets
Enzymes Help
Total enzymes: 1
Enzyme Associated Condition
Methodology
Total methods: 2
Method Category Help
Test method Help
Instrument
Analyte
High-performance liquid chromatography (HPLC)
Enzyme assay
Enzyme activity
radiochemical-thin layer chromatography
Clinical Information
Test purpose: Help
Diagnosis; Monitoring
Clinical validity: Help
Approximately 15% of patients with Severe Combined Immune Deficiency are deficient in adenosine deaminase 1 (referred to as ADA) due to deleterious mutations in both copies of the ADA gene. ADA deficiency in erythrocytes, when accompanied by significant elevation in erythrocyte dAXP, is always associated with clinical immune deficiency. However, … View more
View citations (2)
Clinical utility: Help
Establish or confirm diagnosis
View citations (2)

Guidance for management
View citations (1)
  • Gaspar HB, Aiuti A, Porta F, Candotti F, Hershfield MS, Notarangelo LD. How I treat ADA deficiency. Blood. 2009;114(17):3524-32. doi:10.1182/blood-2009-06-189209. Epub 2009 Jul 28. PMID: 19638621.

Target population: Help
patients suspected or known to have combined immune deficiency
View citations (1)
  • Hershfield M, Tarrant T. Adenosine Deaminase Deficiency. 2006 Oct 03 [updated 2024 Mar 07]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Bean LJH, Gripp KW, Amemiya A, editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2024. PMID: 20301656.
Variant Interpretation:
What is the protocol for interpreting a variation as a VUS? Help
cDNA of VUS are transfected into an E.coli strain lacking ADA activity for measurement of expressed ADA. PMID 9758612

Are family members with defined clinical status recruited to assess significance of VUS without charge? Help
Decline to answer.

Will the lab re-contact the ordering physician if variant interpretation changes? Help
Yes. Dr. Hershfield is available to answer questions from physicians and genetic counselors involved in the care and counseling of the patient and family
Recommended fields not provided:
Is research allowed on the sample after clinical testing is complete?, Sample negative report, Sample positive report
Technical Information
Test Procedure: Help
Confirmation by HPLC analysis of AXP and dAXP in extracts of erythrocytes or dried blood spots that were prepared from whole anticoagulated blood; ADA genotype analysis
Test Confirmation: Help
Confirmation by HPLC analysis of AXP and dAXP in extracts of erythrocytes or dried blood spots that were prepared from whole anticoagulated blood; ADA genotype analysis
Test Comments: Help
Prior erythrocyte transfusion complicates interpretation of test results (ADA activity, HPLC determination of dAXP)
Availability: Help
Tests performed
Entire test performed in-house
Analytical Validity: Help
The assay for ADA enzyme activity in erythrocytes identified ADA deficiency in 16% of 899 patients (primarily with known or suspected combined immune deficiency) who had not received red blood cell transfusions. Mean ADA activity in the affected patients was 0.4% of the mean activity in non-affected patients (P = … View more
Assay limitations: Help
as noted, prior erythrocyte transfusion complicates interpretation
View citations (2)
Proficiency testing (PT):
Is proficiency testing performed for this test? Help
Yes

Method used for proficiency testing: Help
Intra-Laboratory
VUS:
Laboratory's policy on reporting novel variations Help
The person ordering the test is called, emailed, or faxed.
Recommended fields not provided:
Description of internal test validation method, Citations for Analytical validity, PT Provider, Description of PT method, Major CAP category, CAP category, CAP test list
Regulatory Approval
FDA Review: Help
Category: Not Applicable
Additional Information

IMPORTANT NOTE: NIH does not independently verify information submitted to GTR; it relies on submitters to provide information that is accurate and not misleading. NIH makes no endorsements of tests or laboratories listed in GTR. GTR is not a substitute for medical advice. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.