A multicenter, randomized, double-blind, placebo-controlled, multiple dose study to investigate safety and tolerability of RO5186582 in individuals with Down syndrome (Study BP25543).

People with Down syndrome can have cognitive problems. Some of these problems include lower-than-average learning, memory and language ability. One of the goals of this study is to find out whether RO5186582 is safe and effective for treating some of these Down syndrome symptoms. Information from this study will also be used to help find a diagnostic test to identify patients with Down syndrome who may be treated better with RO5186582. About 33 study subjects with Down syndrome will participate in this study at about 10 centers. The centers will be located in the United Kingdom and United States. It is anticipated that up to seven subjects with Down syndrome will participate in this study at Rush University Medical Center.

You may be eligible to participate in this study if you:

• Are between 18 and 30 years of age and have Down syndrome (confirmed by karyotype). Subjects may have standard trisomy 21 or complete unbalanced translocation of the chromosome 21

You will be excluded from this study if you:

• Have mosaic Down syndrome
• Are pregnant or plan to become pregnant during the trial

This is a partial list of eligibility requirements. To inquire about your eligibility, please call the contact number provided. If you wish to inquire via email, please include the title of the study in your message.