Trial of Minocycline to Treat Children With Fragile X Syndrome

Randomized Double-Blind Controlled Cross Over Trial of Minocycline in Children With Fragile X Syndrome

This is a single center study at the UC Davis MIND Institute in patients age 3.5-16 years of age with fragile X syndrome (FXS), funded by a National Fragile X Foundation Grant. It is a controlled trial of minocycline, an antibiotic commonly used in children for infection or for treatment of neurodegenerative disorders. We are investigating its use in FXS because it lowers matrix metalloproteinase 9 (MMP9) levels, which are high in FXS, and it also strengthens brain connections in the animal models of FXS. We hypothesize that minocycline will likely be helpful for language, behavior and/or cognition in fragile X patients.

This is a single center study at the UC Davis MIND Institute in patients age 3.5-16 years of age with fragile X syndrome (FXS), funded by a National Fragile X Foundation Grant. It is a controlled trial of minocycline, an antibiotic commonly used in children for infection or for treatment of neurodegenerative disorders. We are investigating its use in FXS because it lowers matrix metalloproteinase 9 (MMP9) levels, which are high in FXS, and it also strengthens brain connections in the animal models of FXS. We hypothesize that minocycline will likely be helpful for language, behavior and/or cognition in fragile X patients.

The aim of this study is to carry out a double-blind placebo controlled trial of minocycline treatment in children with FXS who are 3.5 to 16 years of age. At baseline, we will assess behavior and perceptual and cognitive development. After the children have been treated for 3 months with either minocycline or placebo, they undergo the same baseline testing. They will then cross over and be treated for a second 3 months. We will carry out testing again at the end of the second 3 month period. We will also assess the side effects of minocycline treatment throughout the study.

Inclusion Criteria:

• Must have fragile X syndrome with molecular documentation
• Current pharmacological treatment regimen has been stable for at least 4 weeks

Exclusion Criteria:

• Subjects who plan to initiate or change pharmacologic or non-pharmacologic interventions during the course of the study
• subjects who are unable to take oral medication
• subjects who have been on minocycline previously
• subjects who are allergic to minocycline or tetracyclines
• subjects who are pregnant
• subjects with history of lupus or hepatic dysfunction