Frequently Asked Questions about Joining

If you have a question about joining the Twin Registry that has not been answered here, please call us at 1.833.432.8720 or email us at 


Why Join the Washington State Twin Registry?

  • What does it mean to be a Twin Registry member?
  • What are the benefits of joining the Twin Registry?


How do you know I’m a twin? 

  • How did the twin registry get my name and contact information?
  • Why didn’t my twin also receive an invitation to join the Twin Registry?
  • Why does the Washington State DOL ask about twins?


Am I eligible to join the Registry?

  • Can my twin and I join if we are fraternal twins?
  • Can I join the Twin Registry if my twin is deceased or not interested in joining?
  • Can I join the Twin Registry if I am not in contact with my twin?
  • Can my twin who lives outside of Washington or overseas still participate?
  • Can triplets or higher-order multiples join the Twin Registry?
  • Are we too old to join the Twin Registry?
  • Can I enroll my twin children in the Twin Registry?


Completing the enrollment survey

  • Are there different ways that I can complete the enrollment survey?
  • Why does the Twin Registry ask for my twin’s contact information?
  • Do I have to answer all of the questions on the enrollment survey?
  • Why does the Twin Registry ask for my mother’s maiden name?
  • Do I have to provide my social security number to the Twin Registry?


What happens next?

  • How often will I be contacted if I decide to join the Twin Registry?
  • How will I be chosen for a study?
  • What does a study invitation look like?


Participating in studies

  • What types of studies does the Twin Registry conduct or facilitate?
  • What safeguards protect Twin Registry members who participate in research studies?
  • Will I receive results from the study I participated in?
  • Will my twin and I get to learn if we are identical or fraternal?


Personal Information and Privacy

  • How does the Twin Registry protect my privacy?
  • Who has access to my personal information?
  • Under what circumstances will my information be released?