Is stuttering genetic? Three people in my family stutter

Is stuttering genetic? Three people in my family stutter My mom, brother and my mom’s sister all stutter. They all started when they were kids. My moms stutter is very mild and she’s always been able to mask it well because she has a strong vocabulary and can quickly find other words when she feels she about to stutter on a certain word. My brother’s stutter is moderate he stutters about every other sentence or so and when he’s nervous it’s worse. At first I thought his stutter could be inherited by imitation but my mom barely stutters so I don’t understand why his is so much worse. My mom’s sister’s stutter is very severe, every other word or so. Just wondering if anyone has insight.