Seizures and abnormal EEG were present in many patients, including those with the smallest deletion or just a point mutation in SHANK3. This was also true for gastroesophageal reflux disease, hypotonia, sleep disturbances, abnormal brain MRI and certain dysmorphic features (for example, dolichocephaly, long eyelashes, dysplastic nails, large fleshy hands and full lips). The gene discussed is SHANK3; the disease is gastroesophageal reflux disease.