Overview: ITGB2 Mutation TestIntroduction: The ITGB2 Mutation Test tests for ITGB2 gene mutations to diagnose leukocyte adhesion deficiency, causing frequent infections, aiding in genetic diagnosis. Affecting 1 in 1,000,000 people, leukocyte adhesion deficiency poses diagnostic challenges due to rare presentation. Following 2023 American Academy of Allergy, Asthma & Immunology (AAAAI) guidelines, it uses PCR/sequencing for high accuracy, supporting molecular pathology screening. This test is essential for diagnosis, genetic counseling, and improving outcomes in immunology.
Other Names: ITGB2 Gene Test, LAD Assay.
FDA Status: Laboratory-developed test (LDT), meeting pathology standards for diagnostic reliability.
Historical Milestone: ITGB2 mutation testing began in the 1990s with research by Anderson, who identified the gene. PCR/sequencing advancements in the 2000s by Illumina improved detection, surpassing earlier linkage analysis.
Purpose: Detects ITGB2 mutations to diagnose leukocyte adhesion deficiency, guides supportive care, and evaluates patients with frequent infections, aiming to manage disease.
Test Parameters: ITGB2 mutation status
Pretest Condition: No special preparation required. Collect whole blood, buccal swab, or saliva. Report history of infections.
Specimen: Whole Blood (EDTA, 3-5 mL), Buccal Swab (sterile swab, 1-2 swabs), Saliva (sterile container, 1-2 mL); 4 mL whole blood in EDTA tube. Transport in a biohazard container.
Sample Stability at Room Temperature: 24 hours
Sample Stability at Refrigeration: 1 week
Sample Stability at Frozen: 1 month
Medical History: Document frequent infections. Include current medications or family history.
Consent: Written consent required, detailing the test's purpose, disease risks (e.g., sepsis), and sample collection risks.
Procedural Considerations: Uses PCR/sequencing to detect mutations, requiring labs with thermal cyclers. Results available in 5-7 days. Performed in labs with strict handling.
Factors Affecting Result Accuracy: Sample degradation or contamination can affect results. Medications may not affect results but require correlation.
Clinical Significance: Positive mutation confirms leukocyte adhesion deficiency, guiding therapy. Early management might prevent complications, while untreated cases lead to death. Normal results may require immune tests.
Specialist Consultation: Consult an immunologist or genetic counselor for interpretation.
Additional Supporting Tests: Neutrophil function test, flow cytometry, or genetic panel to confirm diagnosis.
Test Limitations: Specific to ITGB2; correlation with clinical status needed. False negatives possible with other mutations.
References: AAAAI Guidelines, 2023; Journal of Immunology, Anderson DC, 2022.
