Stuttering is an abnormality in speech that affects the rhythm of speech. People who stutter
know what they wish to say, but at the time are unable to say it because of involuntary
repetition, unnecessary lengthening (prolongation), or early stopping (cessation). Stuttering
is characterized by repetitions or prolongation of the first syllable, or silent
prolongations, sometimes known as blocks.
Researcher intend on studying the genetic basis for stuttering. The goal of the study is to
find the genes that help cause stuttering and determine regions of the human genetic make-up
(genome) that are linked to stuttering.. To do this researchers will study the patterns of
inheritance in families who have had members who stutter.
The study has two objectives.
The first objective is to develop a large collection of DNA samples from individuals in
stuttering families, that will include both members that stutter and who do not stutter.
The second objective of the study will be to find out the basic combination of genes
(genotype) making up all of the participants DNA. Once this is completed researchers hope to
map out and find areas or regions of DNA that are linked to stuttering.
Genetic linkage is the initial step in positional cloning, and the cloning of genes which
predispose individuals to stuttering is a long term goal of this research study.<TAB>
A primary goal of this study is to ascertain regions of the human genome which show genetic
linkage to stuttering. Genetic linkage will be determined by first obtaining genomic DNA from
both affected and unaffected adults and children from families containing pairs of
individuals who stutter as adults. Individuals who stutter from genetically isolated
populations will also be sampled. Phenotype will be assigned by a speech-language
pathologist, and DNA samples will be obtained from affected and unaffected family members
from 2 cc. of saliva or from 20 cc. of blood. These DNA samples will then be genotyped using
markers distributed across the human genome. The genotypic information analyzed to determine
which markers or variants show linkage to stuttering. The initial goal of this study is to
identify specific genetic variants, which predispose individuals to stuttering. No genetic
information will be provided back to participants. A secondary goal of the study will be to
perform broad clinical evaluations of the individuals found to have mutations that cause
stuttering. These will take place at the NIH Clinical Center and will include standard
procedures including history and physical, neurological exam, audiological exam,
ophthalmologic exam, electromyographic (EMG) exam, electroencephalography (EEG), X-rays,
speech evaluation, and brain imaging including MRI and fMRI.
- INCLUSION CRITERIA:
- Individuals age 8 and older.
- Individuals age 6-8 with a family history of persistent stuttering
- Have stuttering that persists for a period of 6 months or more or are a family member
of that person
- For the Phase 2 imaging studies, we will be enrolling up to 25 healthy volunteers to
- Stuttering only as a young child (not beyond the age of 5)
- Cannot provide informed consent or have a parent/guardian to provide consent
- Developed stuttering following trauma to the central nervous system.
- Chronic medical conditions that prevent informed consent or clear evaluation of
stuttering, including stroke, dementia, and degenerative neurological disease.