Joubert Syndrome is a rare genetic disorder characterized by decreased muscle tone, difficulties with coordination, abnormal eye movements, abnormal breathing pattern and cognitive impairment. These issues are due to abnormal brain development, resulting in decreased size of the cerebellar vermis and other brain abnormalities that appear as the "molar tooth sign" on a brain MRI. Although rare, several hundred individuals with Joubert Syndrome have been reported in the medical literature. Mutations in at least 10 genes cause Joubert Syndrome, accounting for ~50% of patients. Subsets of individuals with Joubert Syndrome can also have polydactyly (extra fingers or toes), as well