We're learning a lot about the underlying genetic differences of people who stutter. We've known for decades anecdotally that stuttering runs in families, but there are researchers like Dr. Dennis Drayna and Dr. Shelly Jo Kraft who have done and are doing really interesting work and identified many genes that are different in people who stutter. Apart from the genes themselves, I think what's most interesting is how well this genetic research is corresponding to the Neuroimaging work done by Dr. Soo-Eun Chang and others. For example, genes directly responsible for some white matter tracts in the brain have been shown to be different in people who stutter, but that matches well with the Neuroimaging data showing that these white matter tracts are indeed different! Dr. Shelly Jo Kraft is also doing amazing field work, going into communities and families with very high prevalences of stuttering, and doing genetic sampling in those high prevalence families/communities to better understand the genes themselves and how they are inherited/transmitted.