Stuttering & Genetics

Instructor: Justine Fritzel

Justine has been a Registered Nurse for 10 years and has a Bachelor's of Science in Nursing degree.

Stuttering is a challenging speech disorder that isn't well understood, but research has shown some evidence of a genetic link. In this lesson, we will learn about stuttering and how genetics may play a part.

What is Stuttering?

Stuttering is a speech disorder that is difficulty with fluency of speaking. More than 3 million people in the United States stutter, and males are more likely to stutter than females. All types of people may have a stutter, including some very famous people. Marilyn Monroe was a famous Hollywood personality who dealt with stuttering. Even U.S. Vice President Joe Biden stuttered!

People who stutter know exactly what they want to say - they just have trouble getting the words out! Stuttering does not reflect any lack of intelligence, and it can be a normal occurrence in early childhood as children learn speech and language skills. Many children outgrow their stuttering, but others continue to deal with stuttering throughout their lives.

Characteristics of Stuttering

There are three common characteristics of stuttering: repetition, prolongation, and blocks. Let's look at examples of each one.

  • Repetition is repeating a letter of a word until you can get the rest of the word out. 'W-w-w-where is the mall?'
  • Prolongation is saying a sound of a letter or syllable for an extended time until you can speak the rest of the word. 'Wwwwwwhere is the mall?'
  • Blocks are abnormal stoppages when speaking. 'Wh---ere is the mall?'

You may be picking up on the fact that each characteristic of stuttering occurs as a way to take the time needed to get the rest of the word spoken. It's not intentional, and it can lead to increased anxiety and fear of speaking.

Developmental Stuttering

Stuttering can occur during development or can be caused by a brain injury or traumatic emotional event.

Developmental stuttering begins in early childhood, and it's the most common type of stuttering. It's like the child's speech just can't keep up with their thoughts!

It is not clearly understood why developmental stuttering occurs. Research has shown that brain images show consistent differences when compared with those who do not stutter. Brain imaging in a person with stuttering shows decreased white matter in the left hemisphere of the brain compared with a person who does not stutter.

Stuttering and Genetics

There are additional factors that suggest a genetic link to stuttering. If someone in your family stutters, you are more likely to stutter as well. Let's learn more about genetics to help you understand their role in stuttering.

Our bodies are made up of trillions of cells. Within each cell there is a nucleus, or control center. Our genes are contained within the nuclei of our cells. Genes are like the Betty Crocker recipe book: They give off specific instructions to the cells to make proteins. Proteins are the Lego pieces to build everything in our bodies, from hair to bones. You get all your genes from your parents, so if a condition has a genetic cause, it can be passed from parent to child.

Researchers have identified several gene mutations associated with some cases of stuttering. Picture the genes like the police officer directing traffic. The genes direct the 'cars' to go in the right direction, and without the police officer directing the traffic, the cars don't have any direction! This results in a traffic jam or accidents. In the same way, a gene without proper trafficking results in dysfluency, or lack of fluency of speech. Or to use our previous example: If the genes are trying to make 'soup' without a recipe, they may just result in a bowl full of random ingredients that don't taste so good!

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account