Twin Zygosity
Also known as: TWINZYG
Use
The Twin Zygosity test is used to determine whether twins are monozygotic (identical) or dizygotic (fraternal). Monozygotic twins result from a single fertilized egg splitting into two embryos, while dizygotic twins come from the fertilization of two separate eggs during the same menstrual cycle. Determining zygosity can be important for medical, legal, and psychological reasons, as monozygotic twins can have different medical risk profiles compared to dizygotic twins.
Special Instructions
Results from both twins will be compared and reported; therefore, a test must be ordered for and a sample submitted from each individual. Informed consent for genetic testing is required for New York patients.
Limitations
Diagnostic errors can occur due to rare sequence variations. The test's accuracy is contingent on proper specimen handling and analysis. It has not been cleared or approved by the U.S. Food and Drug Administration but is performed in a CLIA-certified laboratory and intended for clinical purposes. Interpretation may be affected by factors like blood transfusions, bone marrow transplants, or somatic mutations affecting the markers analyzed.
New York Approved
Methodology
PCR-based (PCR)
Biomarkers
LOINC Codes
- 31208-2
- 55198-6
Result Turnaround Time
5-10 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
2 mL
Minimum Volume
1 mL
Container
Lavender (EDTA), pink (K2EDTA), or yellow (ACD solution A or B)
Collection Instructions
Collect from each twin: Lavender (EDTA), pink (K2EDTA), or yellow (ACD solution A or B).
Patient Preparation
Informed consent for genetic testing is required for New York patients.
Storage Instructions
Refrigerated; also acceptable: Ambient
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 1 week |
| Refrigerated | 1 month |
| Frozen | Unacceptable |