Thank you for your question! We are basing this inventory off of data that was collected from a de-identified electronic health record of disorders that co-occurred frequently in individuals who also stutter. Stuttering is a disorder of unknown etiology and no one gene has yet been identified to cause stuttering. It is likely a polygenic disorder that is contributed to by genes that are also expressed in other ways throughout the body. Through collecting saliva samples and learning more about comorbid disorders in individuals who stutter we hope to find more about what causes stuttering through analysis of clinical phenotypes and DNA. I hope this answers your question somewhat. Thank you for your interest in the survey.