Self‐reported impact of developmental stuttering across the lifespan

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. Readers will be exposed to a summary presentation of the most recent data concerning basic epidemiological factors in stuttering. Most of these factors also pertain to children's risks for experiencing stuttering onset, as well as risks for persistency. The article also aims to increase awareness of the implications of the information to research, and professional preparation that meets the epidemiology of the disorder. Copyright © 2012 Elsevier Inc. All rights reserved.

Stuttering is a disorder of unknown cause characterized by repetitions, prolongations, and interruptions in the flow of speech. Genetic factors have been implicated in this disorder, and previous studies of stuttering have identified linkage to markers on chromosome 12. We analyzed the chromosome 12q23.3 genomic region in consanguineous Pakistani families, some members of which had nonsyndromic stuttering and in unrelated case and control subjects from Pakistan and North America. We identified a missense mutation in the N-acetylglucosamine-1-phosphate transferase gene (GNPTAB), which encodes the alpha and beta catalytic subunits of GlcNAc-phosphotransferase (GNPT [EC 2.7.8.15]), that was associated with stuttering in a large, consanguineous Pakistani family. This mutation occurred in the affected members of approximately 10% of Pakistani families studied, but it occurred only once in 192 chromosomes from unaffected, unrelated Pakistani control subjects and was not observed in 552 chromosomes from unaffected, unrelated North American control subjects. This and three other mutations in GNPTAB occurred in unrelated subjects with stuttering but not in control subjects. We also identified three mutations in the GNPTG gene, which encodes the gamma subunit of GNPT, in affected subjects of Asian and European descent but not in control subjects. Furthermore, we identified three mutations in the NAGPA gene, which encodes the so-called uncovering enzyme, in other affected subjects but not in control subjects. These genes encode enzymes that generate the mannose-6-phosphate signal, which directs a diverse group of hydrolases to the lysosome. Deficits in this system are associated with the mucolipidoses, rare lysosomal storage disorders that are most commonly associated with bone, connective tissue, and neurologic symptoms. Susceptibility to nonsyndromic stuttering is associated with variations in genes governing lysosomal metabolism. 2010 Massachusetts Medical Society

This paper describes a new instrument for evaluating the experience of the stuttering disorder from the perspective of individuals who stutter. Based on the World Health Organization's International Classification of Functioning, Disability, and Health [World Health Organization (2001). The International Classification of Functioning, Disability, & Health. Geneva: World Health Organization], the Overall Assessment of the Speaker's Experience of Stuttering (OASES) collects information about the totality of the stuttering disorder, including: (a) general perspectives about stuttering, (b) affective, behavioral, and cognitive reactions to stuttering, (c) functional communication difficulties, and (d) impact of stuttering on the speaker's quality of life. This paper summarizes scale development, reliability and validity assessment, and scoring procedures so clinicians and researchers can use the OASES to add to the available evidence about the outcomes of a variety of treatment approaches for adults who stutter. As a result of this activity, participants will be able to: (1) identify key issues related to the documentation of treatment outcomes in stuttering; (2) discuss the components of the international classification of functioning, disability, and health as they relate to the documentation of stuttering treatment outcomes; (3) evaluate and use a new measurement instrument for assessing the outcomes of stuttering treatment from the perspective of the person who stutters.