It is important to note that minocycline is not approved to treat Angelman syndrome or to be used in children younger than 8 years old. The study protocol has been reviewed by several physicians and scientists and been deemed safe to proceed. As with any medication the potential for side effects exist. The side effects range from serious to mild and include allergic reactions to upset stomach. In order to minimize this risk, the medical staff will perform a thorough medical history and physical examination before the prescription is issued to ensure no allergy to this medication, penicillin or another tetracycline exists. Discoloration of the teeth is potential adverse effect that exists when taking high doses of MC over long periods of time. The tooth discoloration is permanent and the parent or guardian of the participants will be made aware of this potential side effect prior to enrollment in the study. In other studies using MC, the most common complaint was gastrointestinal upset.