About the Study

Remote visits

To reduce the amount of in-person testing that is needed for our study and to help keep our staff and families safe, we are now completing most of our testing procedures remotely over video chat!

All eligible families (both local and traveling families) will be invited to complete four to five 2 hour video testing sessions to complete several of the behavioral questionnaires and cognitive assessments. Once in-person visits are able to occur, we will see families for an abbreviated visit to complete the remaining cognitive assessments, pubertal measurements, blood testing, and MRI scanning.

As much of our testing is completed remotely now, please help us stay productive while making your contribution to scientific progress from the comfort of your own home!

Who can participate

We are currently recruiting male adolescents:

  • 8-17 years old
  • With typical development OR with confirmed non-mosaic Klinefelter syndrome (47, XXY)

What participation includes

This is a longitudinal study, requiring a total of 4 annual study visits. At each yearly visit, participation includes:

For the child - 

  1. Cognitive and behavioral assessments
  2. Questionnaires and interviews to be completed with trained researchers
  3. Brain imaging via Magnetic Resonance Imaging (MRI) –MRI scans are safe, non-invasive, and do not involve X-rays. They are primarily used to look at the structures of the brain. However, because MRIs involve magnets, we cannot include anyone with metal in their bodies, like braces or other metal implants.
  4. Physical exam by an endocrinologist to check pubertal development - includes measurements like height and weight and briefly looking at and measuring genitals
  5. Small blood draw (1 vial) to check hormone levels


For the parent - 

  1. Questionnaires and interviews regarding your child and self - either administered by trained staff member or answered independently
  2. Cognitive assessment

What the potential benefits are

  1. After each yearly visit, all families are provided with a detailed report discussing the results from cognitive and behavioral evaluations
  2. Early access to study outcomes
  3. Flight/hotel/ground transportation and food costs are covered for the participating child and one caregiver or parent
  4. Families will receive an honorarium of up to $120 for their participation (plus prizes and a picture of your child's brain)


How long the visits take each year

Updated procedures due to COVID-19

Remote Testing

All eligible families (both local and traveling families) are invited to complete four to five 2-hour video testing sessions to complete several behavioral questionnaires and cognitive assessments. These are all completed over Zoom at times that are convenient for our participants. 

Abreviated In-Person Testing

Once remote testing is complete, families are invited  to complete abbreviated in-person testing.  When feasible, families are asked to come to Stanford University to complete the MRI scan, physical exam, and blood draw. Some families may also be asked to go to a local testing facility (Quest Diagnostics) to complete the blood draw. This in-person testing takes about 3 hours. Currently we are only seeing local families in person.

To learn more about how we are working to keep our families and staff safe during these sessions, please click here.

Travel Families

When travel is feasible, traveling families may be invited for abbreviated in-person testing as well. When this time comes, we will be able to cover the cost for one child and a parent to fly or drive to our campus. Additionally, we will be able to cover 1-2 nights at a local hotel depending on your preference and travel plans. In the meantime, traveling families will be asked to complete a blood draw at a local lab (such as Quest Diangostics) around the time they complete their remote testing.

For general information about participant rights, contact 1-866-680-2906