Children with speech impediments other than stuttering

Children with speech impediments other than stuttering We have recently been noticing that my 4 year old son is displaying an unusual habit while speaking. After completing a sentence, he will occasionally repeat the last spoken word in a whisper. If you're familiar with the show The Middle, the youngest son Brick displays a similar habit. After a little research my wife and I found that there was a speech impediment called Palilalia that consists of such a symptom and is linked to Autism and Tourettes. ​ I know that stuttering can be hereditary, although have yet to detect any sign of disfluency speech in my son's speaking. I was wondering if anyone else who stutter's has detected an alternative speech impediment in their children?