Longitudinal Twin Study of Reading Disability

This is the first longitudinal study of reading disability using genetically informative data, and was recently funded by the National Institute on Deafness and Other Communication Disorders (NIDCD).Results obtained from longitudinal studies of learning disabilities can provide information about patterns of stability and change, as well as about the direction and magnitude of relationships among conditions and later outcomes. The purpose of this study is to build on current knowledge and provide new information about the causes of stability and change in reading disability and its dimensions/subtypes, as well as about stability of comorbidity and covariation of reading disability with other abilities and psychopathology. In order to accomplish this goal, we are conducting follow-up assessment of twins and their siblings, both with and without reading difficulties, who have participated in the Colorado Learning Disabilities Research Center (CLDRC; DeFries, et al., 1997). Assessment includes tests of reading performance, reading comprehension, spelling, reading component processes, general and specific cognitive abilities, and psychopathology.