Dyslexia doesn't cause speech difficulties, though. Whoever told you that was misinformed and has misinformed you. Stuttering is a motor-speech disorder. It's more similar to swinging a (very fine, very complicated) bat at a (very fast) fastball than reading. There is a LOT of debate about the causes of stuttering...check out "the monster study" (Tudor study; https://en.wikipedia.org/wiki/Monster_Study). This study was also debunked by Ambrose and Yairi but it still informs a lot of stuttering treatment today that emphasizes thoughts and feelings about stuttering. A lot of practicioners still insist on the psychogenic theory of stuttering (e.g., "I was fine until my parents got divorced, but then it started due to all the fighting"), but there's a lot of debate about it...it's hard to know whether the traumatic event was correlation or causation or both. Still others insist that thoughts and feelings are just secondary effects, and all therapy should be direct treatment of the stutter (like Lidcombe...a behaviorist/Skinnerian approach that has good effects with young children). There does seem to be a genetic component as well as a neurological component. Maybe there is an emotional component as well, but that's harder to pin down.