Genetic epidemiology of stuttering among school children in the state of Tamil Nadu, India

Reduced stuttering for school-age children: A systematic review

BACKGROUND

Treatment of school-age children (6-12 years of age) who stutter is a public health priority. Their clinical needs include a psychosocial focus and stuttering reduction. For the latter clinical need, there is a critical window of opportunity for these children warranting research attention.

PURPOSE

The purpose of the review is to guide future clinical research by establishing (a) what interventions are associated with stuttering reduction for school-age children (b) the reported immediate and longer-term effects of those interventions, and (c) the level of evidence for these interventions in terms of study design.

METHODS

Fourteen databases and three conference proceedings were searched for interventions used to reduce stuttering in school-age children. Primary outcomes were mean stuttering reductions pre-treatment, immediately post-treatment, and any follow-up assessments.

RESULTS

Of the 4305 studies identified from the databases, 67 studies met inclusion criteria. Five different treatment approaches were reported in the literature that might reduce stuttering for a school-age child, but with varying effect sizes. These include (a) operant methods, (b) speech restructuring, (c) combined operant methods and speech restructuring, (d) machine-driven treatments, and (e) treatments with a cognitive behaviour therapy component.

CONCLUSIONS

Operant methods warrant investigation in future clinical trial research, as do variants of speech restructuring. Hybrid approaches showed encouraging results, including speech restructuring variants combined with operant methods or with cognitive behaviour therapy. However, evidence is preliminary only at Phase I and II trials. Several treatments with reported clinical promise have been overlooked for decades and require further investigation.

Stuttering, family history and counselling: A contemporary database

BACKGROUND

Information about genetic influence is useful to when counselling parents or caregivers who have infants and children at risk for stuttering. Yet, the most comprehensive family aggregate database to inform that counselling is nearly four decades old (Andrews et al., 1983). Consequently, the present study was designed to provide a contemporary exploration of the relationship between stuttering and family history.

METHODS

Data were sourced from the Australian Stuttering Research Centre, comprising 739 participants who presented for assessment, treatment, or investigation of stuttering. Reported family history data were acquired from pedigrees collected during assessment. We sought to establish the relation of the following variables to family history of stuttering: incidence, proband sex, parent sex, stuttering severity, age, reported age of stuttering onset, and impact of stuttering. Data were analysed with chi-square tests for independence, logistic and linear regression models.

RESULTS

Results were broadly consistent with existing data, but the following findings were novel. Males and females who stutter have the same increased odds of having a father who stutters relative to a mother who stutters. Males had later stuttering onset than females, with genetic involvement in this effect. There was a greater impact of stuttering for females than males with a family history of stuttering.

CONCLUSION

These findings have clinical applications. Speech-language pathologists may have infant or child clients known to them who are at risk of beginning to stutter. Information from the present study can be applied to counselling parents or caregivers of such children about stuttering and family history.

Communication attitude of Kannada-speaking adults who do and do not stutter

The Communication Attitude Test for Adults who stutter (BigCAT) is an established measure of cognitive traits in adults who stutter (AWS). The primary purpose of the present study was to adapt and validate the BigCAT to the Kannada language. The secondary purpose was to compare AWS' and adults who do not stutter (AWNS) BigCAT-K scores and compare AWS' score in sub-populations in terms of severity and age. The study included a purposive sample of 100 AWS and 317 AWNS. There was high test-retest reliability and solid construct validity, as made evident by the results of the discriminant analysis and cross-validation. Further, as in other investigations with the BigCAT (Vanryckeghem & Brutten, 2019), this self-report test revealed a statistically significant group mean difference between AWS and AWNS, suggesting the presence of a negative attitude towards communication in Kannada-speaking AWS. Further, individuals with severe stuttering had a significantly higher level of speech-associated negative attitude compared to those with mild stuttering. Age does not seem to influence the AWS' speech-associated belief system. Both of these findings augment the existing scant literature on exploring the association between stuttering severity and age on the cognitive dimension of stuttering. The outcomes establish the BigCAT-K as an effective tool in the assessment and subsequent management of stuttering.

Evaluation of recurrent GNPTAB, GNPTG, and NAGPA variants associated with stuttering

Stuttering is a childhood-onset fluency disorder, intertwined with physiological, emotional, and anxiety factors. The present study was designed to evaluate the recurrence of the reported mutations among three previously implicated (GNPTAB, GNPTG, NAGPA) candidate genes, in persons with stuttering from south India. Mutation screening was performed among 64 probands on 12 specific exons, by Sanger sequencing. A total of 12 variants were identified, which included five nonsynonymous, five synonymous, and two noncoding variants. Three unrelated probands harbored heterozygous missense variants at conserved coding positions across species (p. Glu1200Lys in GNPTAB, p. Ile268Leu in GNPTG and p. Arg44Pro in NAGPA). Of these, only one variant (p. Glu1200Lys in GNPTAB) cosegregated with the affected status while p. Ile268Leu in GNPTG gene was found to be a rare de novo variant. Although this study identified some previously reported variants that have been claimed to have a role in stuttering, we confirmed only one of these to be a likely causal de novo variant (p.Ile268Leu) in the GNPTG gene at an allele frequency of 0.8% (1/128) in the families with stuttering.