Well, this is incredible: "The gene sequence had a strange repeating structure, CAGCAGCAG… continuing for 17 repeats on average (ranging between 10 to 35 normally), encoding a huge protein that’s found in neurons and testicular tissue (its exact function is still not well understood). The mutation that causes HD increases the number of repeats to more than forty – a “molecular stutter” – creating a longer huntingtin protein, which is believed to form abnormally sized clumps when enzymes in neural cells cut it. The more repeats there are, the sooner the symptoms occur and the higher the severity"

Not the only sequence model that exhibits stutters on repetitive inputs...