There's actually been a fair bit (but I don't know if I'd say a "lot") of work done examining the link between stuttering and genetics. I won't go into \*all\* of the details, but we've found links on chromosomes, 1, 7, 9, 12, 13, 15, 16, and 18. There have even been studies narrowing it down to specific gene mutations (see Kang, Riazuddin, Mundorff et al. 2010). There have also been studies showing differences in genes that code for certain white matter tracts in the brain between people who stutter and those who never have; this supports some neuroimaging data that has found observable differences in brain structure and wiring. It's not exclusively genetic; but studies have estimate that it's anywhere from 70% to 80% genetic, with your environment contributing the rest. If you want to know more, I'd try to find a copy of Dr. Barry Guitar's book *Stuttering*. He has chapters dedicated not just to what we know, but also to the studies that got us to those conclusions. I personally find it very interesting. Hope this helps.