Stuttering as a phenotype for behavioral genetics research.

Stuttering is a broad behavioral phenotype with an adult prevalence of 0.7-1.0%. Family, twin, and segregation studies all indicate that stuttering has a large genetic component to its etiology. The relatively simple phenotype, the early onset, and the apparent rarity of phenocopies of adult stuttering all make stuttering a promising model for the study of the genetics of broad behavioral phenotypes.