What is a Twin Zygosity Testing?

A Twin zygosity test is genetic test that determines if twins are fraternal (dizygotic) or identical (monozygotic).

Twin Zygosity DNA Test

At-Home DNA test kit

An At-Home DNA test is a genetic test that can be performed at home. This testing option cannot be used for any legal purpose. The contents of your DNA sample collection kit will include, buccal swabs, sample envelopes, chain of custody form, sample collection instructions and a prepaid FedEx return envelope.

Please note: Due to New York State Department of Health guidelines NY residents are unable to purchase At-Home DNA testing kits. If you require twin DNA.
How much does a Twin Zygosity test cost?

The cost is $299.99 and up. To order DNA test kit or to schedule an appointment. Contact our office at 877-680-5800 to get started.

A legal test is a DNA test that requires the a chain of custody be established, DNA samples have to be collected by a third-party DNA sample collector, and the testing of your DNA samples will be processed and analyzed by our partner AABB accredited DNA testing laboratory.

Turnaround Times

The turnaround time for your results to be completed is 2 to 3 business days from the date the lab receives your DNA samples.

Upon the completion of your results a copy of your results will be emailed to you and a copy will be mailed to your home.

How accurate is DNA Twin Testing?

Twin zygosity tests used by our partner laboratory uses strict, clinically confirmed testing PCR methods that examine over 20 short tandem repeat loci in the twins’ DNA, as well as the amelogenin gender marker, enabling the tests to determine zygosity with 100% accuracy.

DNA Testing Limitation:

While twin zygosity DNA testing provides a statistical probability that twins are identical (monozygotic) or fraternal (dizygotic), there is always a slight chance of error even with identical test results and a high monozygotic probability.

This small possibility of misclassification is reflected in the probability statistic reported. Submitting DNA from the twins’ parents can enhance the analysis and improve statistical certainty of correctly determining zygosity.

Much like paternity testing, sibling DNA testing aims for very high accuracy, with leading labs achieving over 99% precision in confirming or excluding full biological sibling relationships. Similar stringent standards are applied to twin zygosity statistics to minimize any chance of incorrect zygosity determination.

Specimen collection types:

Cheek swabs is the commonly used method to collect DNA samples. Blood samples are also a viable sample collection option.

Fraternal Twins

What are fraternal twins?

Fraternal twins also known as dizygotic twins, are twins that who are conceived when two separate sperms fertilize to different eggs. Fraternal twins are said to share 50% percent of the same DNA.

Identical Twins
What are identical twins?

Identical twins are also known as monozygotic twins, are twins who are conceived from the same fertilized egg. Identical twins are believed to share 100% of their DNA.

Common reason to perform a zygosity test:

Below are a few reasons parents may perform Twin DNA test.

Confirm twin type – To definitively determine if twins are identical or fraternal, rather than just making an assumption based on appearance. Identical twins look very similar but some fraternal twins can also look alike.

Medical risk factors – There are increased risks for certain medical conditions like twin-to-twin transfusion syndrome in identical twins.

Child development – Identical twins often exhibit more similar traits and abilities. Zygosity helps parents understand influencing factors.

Legal purposes – Confirming zygosity may be necessary in legal situations such as inheritance claims, establishing identity, immigration issues.

Insurance coverage – Some insurance policies may cover cover zygosity DNA testing if there is medical reasons.

Additional DNA Testing Options