Language Phenotype for Reading and Writing Disability: A Family Approach

Abstract

A theory-driven battery of 23 psychometric measures of reading, writing, and related language processes was administered to 102 probands (affected children in Grades 1 to 6 with documented reading problems, writing problems, or both) and both of their biological parents. Affected children and parents were compared on the structural relationships between related language processes (Verbal IQ [VIQ], orthographic, phonological, and rapid naming skills), component reading, (accuracy, rate, comprehension) and writing (handwriting, spelling, composition) skills. The orthographic factor had significant paths to all reading and writing skills, except reading comprehension, in both probands and adults. The phonological factor had significant paths to all reading and writing skills except reading rate and handwriting in probands, but in affected adults only if VIQ was removed. Rapid naming had significant paths only to reading rate in probands and adults. VIQ had significant paths to reading comprehension in probands and adults, and to reading accuracy, reading rate, spelling, and composition in affected adults, but not probands. These results are consistent with the claim of functional systems theory that the same language processes are orchestrated flexibly depending on task at hand. Results for across-age differences in the covariances among related language processes confirmed developmental predictions of connectionist theory. The number of language deficits (based on discrepancy from SCIENTIFIC STUDIES OF READING, 5(1), 59-106

A genome scan in multigenerational families with dyslexia: Identification of a novel locus on chromosome 2q that contributes to phonological decoding efficiency

“…4,45 Under a protocol approved by the Institutional Review Board of the University of Washington, families were initially identified through school age children with reading difficulties. Individuals were included if they met the following criteria, based on scores from 10 specific qualifying tests in a battery of 23 tests plus an IQ test administered by the research team.…”

“…The test battery is described elsewhere. 4,45 Probands had to have a prorated verbal IQ (VIQ) Z90 (Z25%ile) on the Wechsler Intelligence Scale for Children-3rd Edition, 46 and score below the population mean and at least 1 standard deviation below their VIQ on at least one of 10 of the measures of accuracy and speed of single real or nonword reading, accuracy or rate of oral reading of text, spelling, or handwriting automaticity. In fact, most probands were impaired on most or all of the 10 measures.…”

“…In fact, most probands were impaired on most or all of the 10 measures. 4 Children with neurological or psychiatric disorders, pervasive developmental disability, or other medical diagnoses or disabilities known to be associated with poor reading were excluded as probands. Comorbid attention deficit/hyperactivity disorder was not a cause for exclusion.…”

“…3 Diagnosis is usually made during elementary school years, but is complicated by variation in educational experience and developmental changes in phenotypic expression. 4 Although with appropriate educational intervention, most affected individuals eventually achieve some proficiency in reading and writing skills, deficits in fluent oral reading and spelling often persist into adulthood [5][6][7][8][9] and may have long-term educational, economic, and social repercussions.…”

Interventions in Specific Learning Disabilities Through Families

“…Most of these studies confirm LDs are inherited, though they agree that their course can be determined by environmental variables. They point towards the influence of purely educational factors, such as the role of teachers, the teaching method or procedures followed, as well as family variables related to home provision of resources, parental level of education or the family's socioeconomic situation (Berninger, Abbott & Thompson, 2001;Lyytinen, Eklund, & Lyytinen, 2005;Monuteaux, Faraone, Herzig, Navsaria, & Biederman, 2005;Shalev, et al, 2001;Snowling, et al, 2007). The thesis that despite the LD being part of the individual there is a high influence of environmental aspects on its course and severity is further reinforced by these studies.…”