Our Community

The Blog of Our Fragile X World

News for the fragile X community. Research, what findings mean for families, event highlights, and study announcements.


Using Population Data to Learn More About Fragile X Premutation Carriers

Dr. Marsha Mailick, developmental disabilities researcher at the University of Wisconsin-Madison (UW-Madison), recently visited RTI and shared research she and her team have done to learn more about symptoms of fragile X premutation carriers. Their study used data sources that go back decades, including surveys, DNA samples, and electronic health records (EHR).

Filling a gap in research on the fragile X premutation

Past studies about symptoms of the fragile X premutation have been done with women who knew they were carriers and who had a child with fragile X syndrome. Looking at data from people who don't know they are carriers can provide unbiased information about the fragile X premutation. It also allows researchers to look at the impact of the fragile X premutation on women who do not have a child with fragile X syndrome.

The Wisonsin Longitudinal Study

To learn more about premutation carriers, researchers looked at population data (i.e., information about a large group of people) from two long-term studies of people living in Wisconsin. The first used data collected by the Wisconsin Longitudinal Study (WLS). The WLS has been collecting data from the same group of people, starting when they were high school seniors in 1957 and continuing to the present. Participants provided DNA samples and filled out surveys at different time points throughout their lives.

The WLS was not designed to study fragile X. It focuses on collecting data about life events, relationships, and health and well-being. But researchers were able to analyze the DNA samples from nearly 7000 participants in the WLS to find out which participants (both men and women) were premutation carriers. Then they looked at the survey data to find out how often premutation carriers in the WLS reported the same symptoms that premutation carriers in other studies have reported. These symptoms include: depression, anxiety, dizziness, numbness, aching muscles, female reproductive health issues, and having a child with a disability. WLS participants who were premutation carriers reported more aching muscles, dizziness, and numbness than participants without the premutation. Female carriers were also more likely to be younger when they had their last menstrual cycle. Male and female premutation carriers were more likely to have a child with a disability. However, premutation carriers in the WLS did not have higher rates of mental health conditions.

The Marshfield Clinic Personalized Medicine Research Project

Dr. Mailick did a similar study with participants in the Marshfield Clinic Personalized Medicine Research project. In this study, they looked at EHR data and DNA samples from over 20,000 participants going back to the 1970s. The team wanted to see if they could replicate the findings from the WLS participants in a different population-based sample. The results showed that premutation carriers in the Marshfield Clinic study had similar symptoms to those in the WLS.

The importance of population research in learning more about the fragile X premutation

In both studies, Dr. Mailick and her team used population data on a large number of people who did not know their fragile X status. These studies provide important information about the fragile X premutation using objective data gathered from surveys or EHRs. The findings from people who did not know they were carriers confirm earlier reports of the effect of the fragile X premutation on people who knew they were carriers.

These studies could not have been done without the help of thousands of participants taking part over many years by answering surveys, providing DNA samples, and allowing researchers to look at their EHRs.

Share Your Story

What else would you like to know about fragile X premutation? What do you think about research participation in long-term surveys and data registries? Let us know by emailing us! We’d love to hear from you.

About the Author

Rebecca Moultrie

Rebecca Moultrie is a research analyst at RTI International. Her research focuses mainly on helping patients make informed healthcare decisions.