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Examining Physiology and Brain Function in People With the Fragile X Premutation

This study has been completed.
National Institute of Mental Health (NIMH)
Information provided by (Responsible Party):
David Hessl, MD, University of California, Davis Identifier:
First received: April 9, 2009
Last updated: March 5, 2013
Last verified: March 2013
This study will examine whether individuals with the fragile X genetic premutation are likely to have emotional, social, and memory deficits and how the brain may be involved in these deficits.

Fragile X Premutation

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Cross-Sectional
Official Title: Limbic System Function in Carriers of the Fragile X Premutation

Further study details as provided by University of California, Davis:

Primary Outcome Measures:
  • Amygdala and hippocampus volume and function [ Time Frame: Age at time of visit ]

Biospecimen Retention:   Samples With DNA
Saliva and blood samples

Enrollment: 110
Study Start Date: June 2007
Study Completion Date: February 2013
Primary Completion Date: February 2013 (Final data collection date for primary outcome measure)
Men with the fragile X premutation
Healthy men
Brothers of men with the fragile X premutation

Detailed Description:

FMR1 is a gene associated with fragile X syndrome—the most common cause of mental retardation—and with social, emotional, and cognitive deficits. The chance of developing these deficits depends on the number of times the FMR1 gene is repeated on the X chromosome. Individuals with more than 200 copies of the FMR1 gene have the full fragile X mutation, putting them at most risk for mental retardation. Individuals with between 55 and 200 copies of the FMR1 gene have the fragile X premutation; they are much less likely to develop mental retardation, but they may have subtle social, emotional, and cognitive deficits and their children are more likely to have the full fragile X mutation. A theory, which this study will test, holds that the deficits of people with the fragile X premutation are caused by dysfunction in the limbic system. The limbic system consists of a group of structures in the brain that govern emotions and behavior. This study will examine people with the fragile X premutation to determine whether and to what extent they have emotional, social, and memory deficits. The study will also determine whether changes in fragile X gene function are related to increased deficits and how the brain, and specifically the limbic system, may be involved in these deficits.

Participation in this study will last 2 days. Participants will undergo several hours of testing at a lab on back-to-back days. Testing on the first day will include the following: providing several saliva samples; undergoing neuropsychological testing, in which participants will solve different types of problems and be interviewed about their emotional and social experiences; and undergoing a physical exam and blood draw.

Testing on the second day will include the following: an MRI scan, which will take pictures of the brain both while participants are resting and while they are performing certain tasks; more neuropsychological testing similar to that from the day before; and questionnaires about emotional and social experiences. A family member will also be asked to fill out a questionnaire about the participant. On 2 other days, participants will be asked to collect saliva samples while at their homes and send the samples to the study researchers. In addition, the researchers will keep in contact with participants in case any follow-up is needed over the next few years.


Ages Eligible for Study:   18 Years to 45 Years   (Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Members of the general population, those with the fragile X premutation, and the brothers of those with the fragile X premutation

Inclusion Criteria:

  • Possesses FMR1 premutation or is part of the general population control group
  • Normal or corrected vision
  • Speaks English

Exclusion Criteria:

  • Presence of contraindication for brain MRI, such as having metal in the body
  • Presence of a major medical condition, such as kidney, heart, or liver disease
  • Presence of a neurological disorder
  • Current alcohol or drug abuse or dependence
  • History of head trauma
  • History of brain infection
  • Medication affecting cerebral blood flow
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00879502

United States, California
M.I.N.D. Institute, U.C. Davis
Sacramento, California, United States, 95817
Sponsors and Collaborators
University of California, Davis
National Institute of Mental Health (NIMH)
  More Information

Additional Information:
Responsible Party: David Hessl, MD, Associate Professor, Principal Investigator, University of California, Davis Identifier: NCT00879502     History of Changes
Other Study ID Numbers: R01MH078041 ( US NIH Grant/Contract Award Number )
Study First Received: April 9, 2009
Last Updated: March 5, 2013

Keywords provided by University of California, Davis:
Fragile X Premutation
Fragile X
Brain Function processed this record on May 23, 2017