Zygosity Testing (Multiple Births)
Use
This test is crucial for determining genetic risk in cases where one twin or triplet is affected with a genetic disorder for which specific genetic testing is unavailable or the available testing is uninformative. It is also useful for assessing prenatal risks when one fetus of multiples is known to be affected. Moreover, it aids in organ or bone marrow transplantation compatibility testing and serves familial or parental interest, providing pivotal genetic insights for multiples and their family planning.
Special Instructions
Not provided.
Limitations
This test is not designed for medico-legal or forensic purposes, as chain of custody documentation is unavailable. The results are suggestive and should be interpreted in the context of clinical findings, family history, and other laboratory data. Errors in interpretation may occur if information is incomplete or inaccurate. Nonpaternity can be detected but is not the primary focus of this test. Specimen availability from all family members enhances accuracy, but if parental blood is not available, the results may be less informative.
Methodology
PCR-based (Microsatellite Markers)
Biomarkers
No genes
Gene
LOINC Codes
- 55198-6 - Zygosity Bld/T
- 50397-9 - Mol dx interp Bld/T Ql
- 69548-6 - Genetic var assess
- 69965-2 - Clinical cytogeneticist review
- 42349-1
- 31208-2 - Specimen source
- 85069-3 - Lab test method
- 18771-6 - Provider signing name
Result Turnaround Time
5-12 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
Not provided
Container
Lavender top (EDTA) or yellow top (ACD)
Collection Instructions
Invert several times to mix blood. Send whole blood specimen in original tube. Do not aliquot.
Patient Preparation
A previous hematopoietic stem cell transplant from an allogenic donor will interfere with testing.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 days |
| Refrigerated | 4 days |
| Frozen | 4 days |
