Yes, there were able to breed stuttering mice, [https://www.nih.gov/news-events/news-releases/nih-study-mice-identifies-type-brain-cell-involved-stuttering](https://www.nih.gov/news-events/news-releases/nih-study-mice-identifies-type-brain-cell-involved-stuttering) Google for "stuttering mice" there are multiple other articles.