Colorado longitudinal twin study of reading disability

Wadsworth, Sally J.; DeFries, John C.; Olson, Richard K.; Willcutt, Erik G.

doi:10.1007/s11881-007-0009-7

Cited by 44 publications

(51 citation statements)

References 51 publications

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“…Participants included 72 participants with dyslexia and 65 controls from the CLDRC who were included in our earlier subtyping study (Peterson et al, 2013) and who returned for follow-up as part of the LTSRD (Wadsworth et al, 2007). Participants were originally tested between the ages of 8 and 13.5 (M = 10.01, SD = 1.50) and were retested an average of 5.32 years later (SD = 0.82 years) when they were between 12 and 22 years of age (M = 15.33, SD = 1.78).…”

Section: Methodsmentioning

confidence: 99%

“…A subset of these children returned for further testing an average of 5 years later, as part of the Colorado Longitudinal Twin Study of Reading Disability (LTSRD; Wadsworth, DeFries, Olson, & Willcutt, 2007). In the present investigation, we applied the same subtyping criteria to these individuals to evaluate the stability of word reading profiles over this time period and thus inform the validity of the distinction.…”

Section: Introductionmentioning

confidence: 99%

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Longitudinal Stability of Phonological and Surface Subtypes of Developmental Dyslexia

Peterson

Pennington

Olson

et al. 2014

Scientific Studies of Reading

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Limited evidence supports the external validity of the distinction between developmental phonological and surface dyslexia. We previously identified children age 8 to 13 meeting criteria for these subtypes (Peterson, Pennington, & Olson, 2013), and now report on their reading and related skills approximately 5 years later. Longitudinal stability of subtype membership was fair and appeared stronger for phonological than surface dyslexia. Phonological dyslexia was associated with a pronounced phonological awareness deficit, but subgroups otherwise had similar cognitive profiles. Subtype did not inform prognosis. Results provide modest evidence for the validity of the distinction, although not for its clinical utility.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Longitudinal Stability of Phonological and Surface Subtypes of Developmental Dyslexia

Peterson

Pennington

Olson

et al. 2014

Scientific Studies of Reading

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“…Still, in relation to these skills, a classification of the degree of severity exists, which takes into consideration and can vary according to the level of education, age, and received interventions. Longitudinal studies indicate that dyslexia is a persistent situation and not a transient developmental delay [3,4].…”

Section: Introductionmentioning

confidence: 99%

Effects of a Phonological Reading and Writing Remediation Program in Students with Dyslexia: Intervention for Specific Learning Disabilities

Ferraz¹,

Gonçalves²,

Freire³

et al. 2018

Folia Phoniatr Logop

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Objective: To determine the effects of a phonological remediation reading and writing program in individuals with dyslexia, through behavioral and objective evaluations. Patients and Methods: Twenty children diagnosed with dyslexia, aged 8–14 years, were included in this study. Group I (GI) was composed of 10 children who took part in the program, and group II (GII) consisted of 10 subjects who did not take the remediation. The pre-testing evaluated phonological awareness, rapid naming, working memory, reading and writing of words and nonwords, thematic writing, and auditory evoked potential – P300. The type of stimulus used was the speech (20% of rare stimulus and 80% of frequent stimulus), intensity of 80 dBNa. The rare stimulus was the syllable /da/, and the frequent stimulus was the syllable /ba/. Next, the Phonological Reading and Writing Remediation Program was applied in 24 cumulative sessions, twice a week, each with a duration of 30 min. In the post-testing (at the end of the program), all the tests of the pre-testing were reapplied. Results: There was a statistically significant difference (between pre- and post-testing) in phonological awareness, rapid naming, working memory, thematic writing, writing and reading words and nonwords, as well as in the latency of the P3 component of P300 in GI, while GII maintained the same difficulties. Conclusion: The phonological remediation program showed to be a therapeutic method of fast beneficial effects in written language of individuals with dyslexia. However, the wide age range and the size of the sample could be considered a limitation of this study – it interferes with the generalization of results.

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“…The heritability of reading difficulties ranges from 30 to 72% (DeFries and Gillis 1993; Wadsworth et al 2000;Harlaar et al 2005;Hawke et al 2006;Wadsworth et al 2007). Genes influencing reading are distributed throughout the genome, with evidence for linkage of RD, reading skills or related phenotypes reported to at least 10 chromosome regions (Paracchini et al 2007;Scerri and Schulte-Korne 2010).…”

Section: Introductionmentioning

confidence: 99%

Genetic Variation in the KIAA0319 5′ Region as a Possible Contributor to Dyslexia

et al. 2011

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Reading disabilities (RD) have been linked and associated with markers on chromosome 6p with results from multiple independent samples pointing to KIAA0319 as a risk gene and specifically, the 5' region of this gene. Here we focus genetic studies on a 2.3 kb region spanning the predicted promoter, the first untranslated exon, and part of the first intron, a region we identified as a region of open chromatin. Using DNA from probands with RD, we screened for genetic variants and tested select variants for association. We identified 17 DNA variants in this sample of probands, 16 of which were previously reported in public databases and one previously identified in a screen of this region. Based on the allele frequencies in the probands compared to public databases, and on possible functional consequences of the variation, we selected seven variants to test for association in a sample of families with RD, in addition to four variants which had been tested previously. We also tested two markers 5' of this region that were previously reported as associated. The strongest evidence for association was observed with alleles of the microsatellite marker located in the first untranslated exon and haplotypes of that marker. These results support previous studies indicating the 5' region of the KIAA0319 gene as the location of risk alleles contributing to RD.

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Colorado longitudinal twin study of reading disability

Cited by 44 publications

References 51 publications

Longitudinal Stability of Phonological and Surface Subtypes of Developmental Dyslexia

Longitudinal Stability of Phonological and Surface Subtypes of Developmental Dyslexia

Effects of a Phonological Reading and Writing Remediation Program in Students with Dyslexia: Intervention for Specific Learning Disabilities

Genetic Variation in the KIAA0319 5′ Region as a Possible Contributor to Dyslexia

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