Zygosity testing is available to evaluate whether twins are monozygotic or dizygotic based on the presence of specific alleles from a panel of highly-polymorphic short tandem repeat (STR) markers. Template DNA will be extracted from the twins, the mother and the father. STR allele profiles are then established for each individual. The informative STRs are then used in Bayesian calculations to determine the likelihood for monozygotic or dizygotic twinning.
Indications for Testing:
- Twin pregnancy with medical issue
- Twin delivery with medical issue
- Medical issue in one twin
- Parental concern
Sample Requirements: NOTE **** parental blood samples are preferred as well.
- Blood: Infants: 2-3 mL whole blood in purple top EDTA tube
- Children (>2 years) and Adults: 5-7 mL whole blood in purple top EDTA tube
- Cultured amniocytes
- Cultured chorionic villi cells
Sample Handling: Blood samples stored overnight should be refrigerated or kept cold. Blood samples should never be frozen. Specimens being sent from outside facilities should be packaged with a cold pack according to standard medical safety practices. The specimen should be shipped by overnight priority [scheduled to arrive by Friday AM at the latest].
Shipping Address: Center for Human Genetics Laboratory
10524 Euclid Ave, 6th Floor
Cleveland, OH 44106
216-983-1134
For local samples, please call the Center for Human Genetics Laboratory (216-983-1134) to arrange for sample pick-up.
Turn Around Time: 3-9 days
Cost/CPT codes: $1243.63 / 83900 (x2), 83901 (x14), 83909 (x2), 83912, 83890 (x2)