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.

-INCLUSION CRITERIA:

i. Normal Language Development, Hearing and Cognition

ii. The following screening tests previously published with norms were found to have a
good distribution for determining normal functioning in adolescents and adults as all
subjects did not hit ceiling and all had scores greater than or equal to the 80th
percentile. These tests are being used to ensure that subjects affected with stuttering or
FPPD do not have other disorders such as hearing loss, language delay, or mental
retardation.

Peabody Picture Vocabulary Test III (PPVT-III)

Expressive Vocabulary Test (EVT)

Oral Speech Mechanism Screening Examination

Revised Token Test; Token test for Children

Test of Non verbal intelligence (TONI-2)

Digit Span subtest of the WICS-R

Audiometric Screening

Goldman Fristoe Test of Articulation

WUG Test of Morphological Encoding

Test of Auditory Comprehension of Language (TACL)

Khan-Lewis Phonological Analysis

INCLUSION CRITERIA FOR IDENTIFYING AND QUANTIFYING STUTTERING:

The Stuttering Severity Index -3 (Riley, 1981) has been found to be accurate for
identifying and assessing the severity of stuttering during conversational speech. For the
inclusion of a stuttering subject we require:

i. A total overall score of 11 or greater between 3 and 17 years,

ii. A total overall score of 18 or greater from age 18 and above.

INCLUSION CRITERIA FOR IDENTIFYING FPPD:

i. A family history of an autosomal dominant pattern of inheritance of the speech disorder
over several generations with persistence into adulthood in some cases,

ii. Speech symptoms during conversational speech include: deletion of final consonants;
syllable reduction and syllable deletion; deletion of grammatical markers such as copulas,
auxiliaries, prepositions, connectives; poor ability to self-correct; poor awareness of
errors; and consonant cluster reduction.

iii. Greater than 9% discourse errors during analysis of a sample of 300 syllables.

iv. A discrepancy of 30 points (1 and 1/2 Standard Deviations) between receptive (the
higher score) and expressive percentile score on the PPVT III and Expressive Vocabulary
Test.

v. For subjects greater than 7 years of age, a phonological process rating of 3 or more
for any phonological process on the Khan-Lewis Phonological Analysis. For subjects less
than 7 years of age, a phonological process rating of 3 or more on 2 phonological
processes on the Khan-Lewis Phonological Analysis. Finally, any subjects with a non
developmental phonological process error will be identified as potentially having FPPD.

EXCLUSION CRITERIA:

i. Anyone with a hearing loss will be excluded from participation during the diagnostic
testing.

ii. Children with delayed language, more than 1 year delay from norms on receptive and
expression language testing will be excluded.

iii. Language impairment: scores more than 2 standard deviations below the age appropriate
score on the standardized language tests listed under the inclusion criteria.

iv. Cognitive impairment: scores more than 2 standard deviations below the age appropriate
score on the standardized cognitive tests listed under the inclusion criteria.

v. Bilingual non-native English speakers - Studies have demonstrated that brain
organization for speech and language may differ in bilingual persons. It is hypothesized
that this may alter speech motor learning and thus kinematic data from non-native English
speakers would differ from native English speakers. Therefore, only native-American
English speakers, with only one language spoken in the home, will be included.