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.

Condition
Stuttering

The 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 by buccal swab or by 20 cc blood draw. These DNA's will then be genotyped using markers distributed across the human genome, and the genotypic information analyzed to determine which markers show linkage to stuttering. Genetic linkage is the initial step in the process of positional cloning, and the cloning of genes which predispose individuals to stuttering is a long term goal of this research. No genetic information will be provided back to participants.

Genders Eligible for Study:  Both

Accepts Healthy Volunteers

Criteria

INCLUSION CRITERIA:
This study includes individuals 8 years of age and over.
This study also requires stuttering that persists for a period of 6 months or more, which is taken as a standard minimum period that defines stuttering.
This study includes both males and females, although families with affected females are specifically solicited, since females are less afflicted with this disorder in adulthood.
This study includes all racial and ethnic groups, and will specifically seek stutterers from genetically isolated populations (e.g. Ethnic Israeli, West Africa), since these may provide increased power to detect linkage and subsequently narrow the position of the genes involved.
EXCLUSION CRITERIA:
Families in which affected family members (beyond the proband) stuttered only as children.
Families with no clearly affected individuals beyond the proband.
Cognitively impaired individuals, in the instances that their impairment prevents understanding and free decision-making regarding the Informed Consent.
Individuals who developed stuttering following trauma to the central nervous system.
Individuals with chronic medical conditions that prevent clear evaluation of stuttering, including stroke, dementia, and degenerative neurological disease.

Maryland
      National Institute on Deafness and Other Communication Disorders (NIDCD), 9000 Rockville Pike,  Bethesda,  Maryland,  20892,  United States; Recruiting

Study ID Numbers:  970057; 97-DC-0057
Record last reviewed:  January 8, 2004
Last Updated:  January 8, 2004
Record first received:  November 3, 1999
ClinicalTrials.gov Identifier:  NCT00001604
Health Authority: United States: Federal Government
ClinicalTrials.gov processed this record on 2004-11-08