• We invite your child with Fragile X syndrome to join in the foXtail study
  • This invitation tells you a more about the study
  • We want to see if a new medication, RO4917523, helps people with Fragile X syndrome
  • Have a talk about the foXtail study with your family/child’s caregivers and child
  • It is your and your child’s choice if you want your child to take part in this study
  • Please consider participating
  • Please contact us if you want to ask questions

We are inviting children ages 5 to 8 years old with Fragile X syndrome to take part in a study. If you might be interested, we will discuss it with you, and give you more information. We will answer all your questions. Please ask us anything you want.

Why is the study being done?

This is a research study for an experimental oral medication (taken by mouth) called RO4917523 that is being developed for Fragile X syndrome.

We hope to learn about the medicine’s safety, how well your child’s body manages the medicine (tolerability), how much medicine is in your child’s body (pharmacokinetics), and if it works on symptoms of Fragile X syndrome.

Who has been invited?

Anyone with Fragile X syndrome who is between 5 and 8 years old may be eligible to take part in this study. You have been invited because you have a child with a genetic diagnosis of Fragile X syndrome who may be eligible. About 45 children in the US will take part in this study.

Are there any expected benefits to taking part in this study?

Your child’s medical condition may improve from taking the study medication RO4917523), although we cannot guarantee that there will be any benefit to your child. By taking part in the study your child may help future patients by providing important information about RO4917523 and the treatment of Fragile X syndrome.

Who decides?

You and your child can choose if you want your child to be in this study. It is OK to say no. If you say no, it will not affect your child’s care or services What would my child and I have to do?

Before doing any tests, the doctor will ask you and your child to sign a consent/assent form. You and your child will need to attend 7 to 8 clinic visits (including the screening and follow-up visits) over the course of about 4 months. Your child will be given either RO4917523 or a placebo during his/her participation in the study.

On the weeks when your child does not have a clinic visit, the study doctor or the research study staff will telephone you to ask you a few questions about how your child is feeling. If more tests are needed, the study doctor may ask you to schedule an additional study visit.

Will information be kept confidential?

Yes. All information about your child will be handled in strictest confidence. We will follow ethical and legal practice.


Travel, accommodation (if needed) and food costs for the clinic visits for you and your child/family will be reimbursed. You will need to keep receipts and provide these to your study doctor or nurse who will reimburse you.

What is the next step?

We would like to tell you more about the study. We can call you or make an appointment to discuss this further. Please contact us by phone or email us:

Nana Welnick,
Research Coordinator
Tel: (720) 777-8608

Dr. Nicole Tartaglia, MD
Dr. Ann Reynolds, MD
Nana Welnick, BS, CCRC