Yes, stuttering has a strong genetic component. The Stuttering Foundation, one of my favorite sources for information about stuttering, says the following on their website: “The evidence for genetic factors in stuttering is overwhelming, with genetic factors playing a role in at least half of all cases. Although stuttering does cluster in families, severity does not. In other words, if you have a family member who stutters, you are more likely to stutter. However, if you have a family member who stutters severely, his or her severity does not put you at additional risk for stuttering nor does it relate to the severity of your own stuttering.” So this could explain why everyone in your family who stutters has a different severity. Here’s the link if you want to read more about it! https://www.stutteringhelp.org/genetic-and-neurological-factors-stuttering