Relation of motor, linguistic and temperament factors in epidemiologic subtypes of persistent and recovered stuttering: Initial findings.

Purpose: The purpose of this study was to determine the presence of any patterns reflecting underlying subtypes of persistence and recovery across epidemiologic, motor, language, and temperament domains in the same group of children beginning to stutter and followed for several years.

Methods: Participants were 58 2-4-year-old CWS and 40 age and gender matched NFC from four different sites in the Midwest. At the end of the multi-year study, stuttering children were classified as Persistent or Recovered.

Defining stuttering for research purposes.

This is a response to a Letter to the Editor entitled "Stuttering prevalence, incidence and recovery rates depend on how we define it: Comment on Yairi & Ambrose' article Epidemiology of Stuttering: 21st Century advances" by Paul Brocklehurst (2013). The criticism was directed specifically toward Yairi and Ambrose' conclusions, based on review of recent studies, regarding the incidence and prevalence of stuttering. In this response, Brocklehurst's arguments and suggestions of criteria for incidence research are discussed and negated.

Epidemiology of stuttering: 21st century advances.

Unlabelled: Epidemiological advances in stuttering during the current century are reviewed within the perspectives of past knowledge. The review is organized in six sections: (a) onset, (b) incidence, (c) prevalence, (d) developmental paths, (e) genetics and (f) subtypes. It is concluded that: (1) most of the risk for stuttering onset is over by age 5, earlier than has been previously thought, with a male-to-female ratio near onset smaller than what has been thought, (2) there are indications that the lifespan incidence in the general population may be higher than the 5% commonly cited in past work, (3) the average prevalence over the lifespan may be lower than the commonly held 1%, (4) the effects of race, ethnicity, culture, bilingualism, and socioeconomic status on the incidence/prevalence of stuttering remain uncertain, (5) longitudinal, as well as incidence and prevalence studies support high levels of natural recovery from stuttering, (6) advances in biological genetic research have brought within reach the identification of candidate genes that contribute to stuttering in the population at large, (7) subtype-differentiation has attracted growing interest, with most of the accumulated evidence supporting a distinction between persistent and recovered subtypes.

Disfluency patterns and phonological skills near stuttering onset.

There is a substantial amount of literature reporting the incidence of phonological difficulties to be higher for children who stutter when compared to normally fluent children, suggesting a link between stuttering and phonology. In view of this, the purpose of the investigation was to determine whether, among children who stutter, there are relationships between phonological skills and the initial characteristics of stuttering. That is, close to the onset of stuttering, there are differences in specific stuttering patterns between children who exhibit minimal and moderate phonological deviations in terms of frequency of stuttering and length of stuttering events? Twenty-nine preschool children near the onset of stuttering, ranging in age from 29 to 49 months, with a mean of 39.

Genetic bases of stuttering: the state of the art, 2011.

Objective: The literature on the genetics of stuttering is reviewed with special reference to the historical development from psychosocial explanations leading up to current biological research of gene identification.

Summary: A gradual progression has been made from the early crude methods of counting percentages of stuttering probands who have relatives who stutter to recent studies using entire genomes of DNA collected from each participant. Despite the shortcomings of some early studies, investigators have accumulated a substantial body of data showing a large presence of familial stuttering.

Characteristics of disfluency clusters over time in preschool children who stutter.

Purpose: Disfluency clusters in preschool children were analyzed to determine whether they occurred at rates above chance, whether they changed over time, and whether they could differentiate children who would later persist in, or recover from, stuttering.

Method: Thirty-two children recruited near stuttering onset were grouped on the basis of their eventual course of stuttering and matched to 16 normally fluent children. Clusters were classified as stuttering-like disfluencies (SLD), other disfluencies (OD), or mixed (SLD and OD combined).

Prevalence of stuttering in African American preschoolers.

Purpose: In this study, the authors sought to determine the prevalence of stuttering in African American (AA) 2- to 5-year-olds as compared with same-age European Americans (EAs).

Method: A total of 3,164 children participated: 2,223 AAs and 941 EAs. Data were collected using a 3-pronged approach that included investigators' individual interactions with each child, teacher identification, and parent identification of stuttering.

Subtyping stuttering I: a review.

Unlabelled: A reliable and practical subtype system of stuttering should enhance all related scientific work concerned with this disorder. Although a fair number of classification systems have been offered, to date, none has received wide recognition or has been routinely applied in research or clinical spheres. Whereas progress has been made in understanding and treating the disorder, for the most part stuttering continues to be viewed and addressed as a unitary problem.

Genetic studies of stuttering in a founder population.

Unlabelled: Genome-wide linkage and association analyses were conducted to identify genetic determinants of stuttering in a founder population in which 48 individuals affected with stuttering are connected in a single 232-person genealogy. A novel approach was devised to account for all necessary relationships to enable multipoint linkage analysis. Regions with nominal evidence for linkage were found on chromosomes 3 (P=0.

Phonological skills and disfluency levels in preschool children who stutter.

Unlabelled: The relation between stuttering and aspects of language, including phonology, has been investigated for many years. Whereas past literature reported that the incidence of phonological difficulties is higher for children who stutter when compared to normally fluent children, the suggestion of association between the two disorders also drew several critical evaluations. Nevertheless, only a limited amount of information exists concerning the manner and extent to which the speech sound errors exhibited by young children who stutter, close to stuttering onset, is related to the characteristics of their stuttering, such as its severity.

The effect of sample size on the assessment of stuttering severity.

The relationships between the length of the speech sample and the resulting disfluency data in 20 stuttering children who exhibited a wide range of disfluency levels were investigated. Specifically, the study examined whether the relative number of stuttering-like disfluencies (SLD) per 100 syllables, as well as the length of disfluencies (number of iterations per disfluent event), varied systematically across 4 consecutive, 300-syllable sections in the same speech sample. The difference in the number of SLD per 100 syllables between the early and later sections of the speech sample was statistically significant.

New complexities in the genetics of stuttering: significant sex-specific linkage signals.

Stuttering is a speech disorder long recognized to have a genetic component. Recent linkage studies mapped a susceptibility locus for stuttering to chromosome 12 in 46 highly inbred families ascertained in Pakistan. We report here on linkage studies in 100 families of European descent ascertained in the United States, Sweden, and Israel.

Identification of traits associated with stuttering.

Unlabelled: Stuttering has been considered a heritable disorder since the 1930s. There have been different models of transmission that have been proposed most involving a polygenic component with or without a major locus. In spite of these models, the characteristics being transmitted are not known.

Prevalence of voice disorders in African American and European American preschoolers.

Several studies have reported prevalence rates for voice disorders in school-aged children. Less is known, however, about such prevalence in preschoolers, and whether racial, ethnic, or cultural diversity may influence it. The presence of voice disorders in a total of 2445 African-American and European-American preschool children, 1246 males and 1199 females, from 2 to 6 years of age is reported here.

Second formant transitions in fluent speech of persistent and recovered preschool children who stutter.

Unlabelled: This study investigated frequency change and duration of the second formant (F2) transitions in perceptually fluent speech samples recorded close to stuttering onset in preschool age children. Comparisons were made among 10 children known to eventually persist in stuttering, 10 who eventually recovered from stuttering, and 10 normally fluent controls. All were enrolled in the longitudinal Stuttering Research Project at the University of Illinois.

Phonological progress during the first 2 years of stuttering.

This report is the third in a series on phonological impairment in children who stutter, comparing its extent in those whose stuttering will be persistent with those in whom that disorder will disappear spontaneously. The first (E. P.

The effect of temporal manipulation on the perception of disfluencies as normal or stuttering.

Unlabelled: The purpose of this investigation was to study the effect of temporal features within repetition of speech segments on the perception of stuttering. Past research has provided evidence that certain temporal aspects of repetitions produced by people who stutter tend to be shorter than those produced by normally fluent speakers. The effect of these temporal factors on the perception of the disfluency as "stuttering" or "normal" has not yet been studied.