stuttering

Researchers at Washington University School of Medicine in St. Louis, including Stuart A. Kornfeld, MD, have obtained new evidence that at least some persistent stuttering is caused by mutations in a gene governing not speech, but a metabolic pathway involved in recycling old cell parts. Beyond a simple association, the study provides the first evidence that mutations affecting cellular recycling centers called lysosomes actually play a role in causing some people to stutter. 

Nearly all animals make sounds instinctively, but baby songbirds learn to sing in virtually the same way human infants learn to speak: by imitating a parent. Now, an international team of scientists, led by the School of Medicine, has decoded the genome of a songbird — the Australian zebra finch — to reveal intriguing clues about the genetic basis and evolution of vocal learning.