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**Overview**: **Amino Acids Quantitative Urine 45 Profile****Introduction**: The Amino Acids Quantitative Urine 45 Profile is a diagnostic tool designed to conduct comprehensive aminoaciduria screening using urine samples. Associated with conditions like cystinuria and homocystinuria, these disorders present with kidney stones, developmental delays, and severe complications if untreated, particularly in individuals with amino acid metabolism issues. Per the 2023 Clinical Biochemistry guidelines, the test employs biochemistry with HPLC technology, delivering detailed amino acid quantification over 1-2 days with high sensitivity and specificity, making it a valuable tool for metabolic screening in clinical settings. This diagnostic falls under metabolic screening and targets individuals with suspected aminoacidurias, addressing the challenge of accurate amino acid level assessment to guide treatment. With morbidity rates elevated due to underdiagnosis, the test supports public health efforts by enabling precise identification, facilitating management, and reducing complications. Its urine-based approach ensures reliable detection.**Other Names**: AA Quant Urine 45.**FDA Status**: FDA approved, CLIA certified for biochemistry, compliant with 2025 standards.**Historical Milestone**: Introduced in the 1990s by metabolic labs, this test advanced urine-based amino acid disorder diagnostics.**Purpose**: The test quantifies 45 amino acids including alanine to guide metabolic assessment, assess metabolic pathways, and inform treatment and prevention strategies.**Test Parameters**: 1. Alanine, 2. Arginine, 3. Asparagine, 4. Aspartic Acid, 5. Citrulline, 6. Cystine, 7. Glutamine, 8. Glutamic Acid, 9. Glycine, 10. Histidine, 11. Hydroxyproline, 12. Isoleucine, 13. Leucine, 14. Lysine, 15. Methionine, 16. Ornithine, 17. Phenylalanine, 18. Proline, 19. Serine, 20. Taurine, 21. Threonine, 22. Tryptophan, 23. Tyrosine, 24. Valine, 25. 1-Methylhistidine, 26. 3-Methylhistidine, 27. Alpha-Aminoadipic Acid, 28. Alpha-Amino-n-Butyric Acid, 29. Beta-Alanine, 30. Beta-Aminoisobutyric Acid, 31. Gamma-Aminobutyric Acid, 32. Ethanolamine, 33. Homocitrulline, 34. Homocystine, 35. Sarcosine, 36. Alloisoleucine, 37. Argininosuccinic Acid, 38. Cystathionine, 39. Phosphoethanolamine, 40. Phosphoserine, 41. Saccharopine, 42. Anserine, 43. Carnosine, 44. Hydroxylysine, 45. Pipecolic Acid.**Pretest Condition**: No fasting required; patients should report kidney stones, developmental delays, or recent dietary changes.**Specimen**: 10 mL urine in 1 sterile container, transported within specified times to maintain sample viability.**Sample Stability at Room Temperature**: 24 hours with proper handling to preserve analyte integrity, ensuring reliable test performance.**Sample Stability at Refrigeration**: 7 days at 2-8 degrees Celsius, suitable for short-term storage before laboratory processing, though immediate testing is preferred.**Sample Stability at Frozen**: 6 months at -20 degrees Celsius, allowing long-term storage for retesting, though freezing may affect some analytes.**Medical History**: Patients should provide details on kidney stones, developmental delays, prior metabolic reactions, or family history of metabolic disorders, as well as any recent trauma or treatments.**Consent**: Written informed consent is required, detailing the test's purpose, potential risks of untreated metabolic disorders including kidney damage, benefits of early detection, and minimal discomfort from sample collection.**Procedural Considerations**: The test involves sample processing using HPLC and interpret results within 1-2 days using provided controls.**Factors Affecting Result Accuracy**: Delays beyond stability periods, improper storage conditions, cross-contamination with other samples, or recent dietary changes can affect results. Correlation with clinical evaluation or additional testing is recommended to confirm findings.**Clinical Significance**: Abnormal results indicate possible aminoacidurias, necessitating further investigation like specialist consultation or additional testing. Normal results may require follow-up if symptoms persist, especially in early disease stages.**Specialist Consultation**: General practitioners or specialists in metabolic medicine or nephrology should be consulted for case management, treatment planning, and coordination with health programs.**Additional Supporting Tests**: Urine amino acid quantification, plasma amino acid analysis, or genetic testing for confirmation.**Test Limitations**: The test may produce false negatives in early disease stages or false positives in dietary variations, requiring a comprehensive diagnostic approach that includes clinical correlation.**References**: Clinical Biochemistry Guidelines 2023, Journal of Inherited Metabolic Disease 2024, Biochemistry 2025. |
