Segregation analysis of speech and language disorders.

Complex segregation analysis was performed on pedigrees ascertained through 45 probands (26 males, 19 females) with a history of preschool speech and language disorders. Hypotheses concerning mode of inheritance were tested using the POINTER segregation analysis program. Although there is strong evidence for familial transmission of this trait, we were unable to distinguish between a major gene and multifactorial transmission model using likelihood-ratio chi-square tests. Future studies with quantitative measures of speech and language disorders are needed to resolve the issue of mode of inheritance for this trait.