‘Stuttering’ mice may help unravel mystery of human speech disorder

Stuttering is the most common speech impediment in the world, nearly 1 out of every 100 individuals in the US are affected. Several years ago researchers identified the specific gene, Gnptab, in which its mutations often causes stutters.

A recent study has discovered that a single gene in an outwardly unrelated gene produces speech problems for both human and mice alike. By playing with the gene associated with speech in humans, scientists had created transgenic mice whose pups altered sounds in their voices parallel to people with stutters.

The team designed a program that detects the number if vocalizations per minute and tracks how many and how long of pauses occurred from the mice pups. The program displayed that the mice pups with the mutated gene experienced less vocalization and longer pauses than the mice pups without the mutated gene. Of course everything between the two groups were the same; the mutated pups were still physically capable to produce the same sounds like the wild type, and a collection of physical and cognitive tasks indicated the stuttering group were otherwise still healthy. This study suggests that despite the disparity of vocalizations within humans and mice, mutations with the gene Gnptab have similar effects with both humans and mice.

Scientists still question how a single mutation in a relatively common cellular housekeeping gene can produce speech disorders, they still can't pin point the exact neurons link to speech. One scientist suggests that maybe these genes may partake in other functions that have not yet been studied in any other context. I'm also curious to understand the concept of stuttering issues disappearing over an amount of years, because I know a few people who have said they were born with a really bad stutter but speak perfectly fine. Granted I'm not too sure if they went through speech therapy to alleviate the stuttering, but if stuttering is produced by a mutation in a gene, how are people able to "grow out of it" ?

http://www.sciencemag.org/news/2016/04/stuttering-mice-may-help-unravel-mystery-human-speech-disorder

Scientists ID 2,000 Genes in Zebra Finch Brain Linked to Singing: May Teach Us About Human Speech Disorders

[caption id="attachment_3942" align="alignleft" width="300" caption="Male zebra finches learn to sing a courtship song between 35 days and 100 days after hatching, which is when they are sexually mature."][/caption]

In this article published by Science Daily Zebra Finch have thousands of genes that allow for singing.  The genes are located in an area of the brain called area X.  Previously scientists did not know just how many genes are involved with speech.  Area X is located in the male Finch's basal ganglia which is also true for humans.  Language is only used by humans but the ability to create new sounds is a skill we share with the Finch.  FoxP2 is the master gene for human speech and speech disorders in Area X.  A mutation in the FoxP2 gene caused a speech disorder in a family in England and a study was published in 2001.  Every family member that was affected with a speech disorder had the same mutation of the FoxP2 gene.  Scientists recently have been learning that behaviors change the way our brain operates.  When you conduct a certain activity specific genes are turned on.  The basal ganglia was removed from a Finch to study the genes.  Scientists have identified most of the genes used for speech in the Finch but so far we do not have that same knowledge for humans.

I think that finding the gene mutation for speech disorders is an important area of research.  Being able to correct the mutation would cure speech disorders which prevent people in participating in some activities and plague their life.   They need to study these genes in other species of animals to determine if it plays a similar role.