Galactose-1-Phosphate Uridyltransferase Biochemical Phenotyping, Erythrocytes
Use
This test is used for determining the biochemical phenotype for galactosemia, especially when enzymatic and molecular results are incongruent. It helps in predicting the GALT phenotype of an individual. Galactosemia is often due to a deficiency of the galactose-1-phosphate uridyltransferase enzyme, leading to serious health issues if untreated. This phenotyping test assists in accurate diagnosis and informs dietary management, reducing acute symptoms and improving prognosis. The test is critical for clarifying results to determine a treatment strategy when discrepancies arise in enzymatic and molecular genetic analysis.
Special Instructions
A quantitative Galactose-1-Phosphate Uridyltransferase level is needed for accurate interpretation. Patient's age is required, and it is recommended to provide recent GALT test results to avoid automatic additional testing. The Biochemical Genetics Patient Information Form may aid interpretation. If submitting multiple specimens, prioritize their testing order. Contact informed consent if ordering for New York clients.
Limitations
Results may be invalid if performed in erythrocytes following a transfusion. Comprehensive interpretation is enhanced when parental specimens are tested concurrently. The test relies on qualitative band patterns and quantitative GALT activity measurements; discrepancies may require follow-up testing. This method may not distinguish between certain phenotypic variants precisely, so additional molecular genetic analysis may be recommended for definitive genotype determination.
New York Approved
Methodology
Other (Isoelectric Focusing)
Biomarkers
LOINC Codes
- 33780-8
- 33780-8
- 18771-6
Result Turnaround Time
4-17 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
2 mL
Container
Lavender top (EDTA)
Collection Instructions
Multiple whole blood tests for galactosemia can be performed on 1 specimen. Prioritize order of testing when submitting specimens.
Causes for Rejection
Gross hemolysis
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 28 days |