Characteristics of Idiopathic Familial Speech Disorders

Objective: Our objective is to determine which factors are involved in the development of stuttering and familial phonological processing disorder and are associated with a familial pattern of inheritance. Study population: The study population is comprised of 8 groups: 1. Children and adults with persistent developmental stuttering; 2. Unaffected siblings of the individuals affected with developmental stuttering or recovered from stuttering 3. Children and adults who have recovered from developmental stuttering; 4. Children and adults with persistent familial phonological processing disorders (FPPD); 5. Unaffected siblings of the individuals affected with FPPD or have recovered from FPPD 6. Children and adults who have recovered from FPPD; 7. Unaffected siblings of the individuals who have recovered from FPPD; 8. Children and adults with normal speech and language development who will comprise the control groups. Design: A Natural history design will be used to compare affected and unaffected family members with healthy volunteers with normal speech and language. Outcome Measures: Genetic markers and pedigree analyses will be used to test familial inheritance patterns. Speech and language development will be compared using indices of speech perception, auditory perception, self monitoring of one's own speech, language complexity, motor complexity, speech learning, phonological processing and verbal/nonverbal memory.