A risk to develop a learning disability has been shown to run in families. Having a positive family history of learning disability seems to account for mean differences in achievement outcomes (reading, math) in that children with a positive family history score significantly lower compared to their peers with no such family history. However, the…

Studies have identified concurrent, longitudinal, and bidirectional associations between language difficulties and internalizing problems. This is commonly explained by social exclusion or withdrawal from peers, but underlying mechanisms are not well understood. This study uses sibling data to investigate if the comorbidity between language…

There is considerable variability in the extent to which young people with developmental language disorder (DLD) experience mental health difficulties. What drives these individual differences remains unclear. In the current article, data from the Twin Early Development Study were used to investigate the genetic and environmental influences on…

In this study, we performed a latent profile analysis of reading and related skills in a large (n = 733) sibpair sample of Russian readers at risk for reading difficulties. The analysis suggested the presence of seven latent profiles, of which two were characterized by relatively high performance on measures of spelling and reading comprehension…

Previous literature has indicated an important association between reading comprehension and both attention-deficit/hyperactivity disorder (ADHD) and homework habits. This investigation sought to extend previous knowledge by providing information about how ADHD and homework behavior (i.e., completing homework regularly) may jointly influence…

The authors examined whether math fluency was independent from untimed math and from reading using 314 pairs of school-aged twins drawn from the Western Reserve Reading and Math Projects. Twins were assessed through a 90-min home visit at approximately age 10 and were reassessed in their homes approximately 1 year later. Results suggested that the…

The genetic and environmental overlap between static and dynamic measures of preschool phonological awareness (PA) and their relation to preschool letter knowledge (LK) and kindergarten reading were examined using monozygotic and dizygotic twin children (maximum N = 1,988). The static tests were those typically used to assess a child's current…

Discriminative language markers and predictive links between early language and literacy skills were investigated retrospectively in the Jyvaskyla Longitudinal Study of Dyslexia in which children at familial risk for dyslexia have been followed from birth. Three groups were formed on the basis of 198 children's reading and spelling status. One…

This study investigated the role of the myelin oligodendrocye glycoportein (MOG) gene to reading disability in 22 children with dyslexia and 96 random controls. Results suggest that, although alleles in the MOG gene may be in linkage disequilibrium with a locus that contributes to reading disability, the MOG gene itself is probably not involved.…

The cognitive and behavioral symptoms of nonverbal learning disabilities (NLD) have been described by previous investigators. Nevertheless, we know far less about the potential genetic contributions that may predispose a child to have NLD. An endophenotype model was investigated in 5 samples of children ages 9 to 15 years: NLD (n = 32); reading…

The genetic and environmental etiologies of 3 aspects of low mathematical performance (math disability) and the full range of variability (math ability) were compared for boys and girls in a sample of 5,348 children age 10 years (members of 2,674 pairs of same-sex and opposite-sex twins) from the United Kingdom (UK). The measures, which we…

This introductory article briefly describes each of the following eight articles in this special issue on the neurology and genetics of learning related disorders. It notes the greater appreciation of learning disability as a set of complex disorders with broad and intricate neurological bases and of the large individual differences in how these…

The present study addresses the distinction between specific (SLI) and nonspecific (NLI) language impairment at an etiological level by estimating the relative genetic and environmental contributions to language impairment in children with SLI and NLI. Drawing on a large longitudinal twin study, we tested a sample of 356 four-and-a-half-year-old…

Comparison of twins (40 identical and 23 fraternal) for mathematics deficits (MD), in which at least one member had a mathematics disability, found evidence for a significant genetic etiology. However, tests for the differential etiology of MD as a function of reading performance level were nonsignificant. (Author/DB)

Examination of methodological issues in the design and interpretation of studies on the genetics of reading disability suggests three tests of increasing rigor for determining whether reading score distributions are categorical and thus not subject to analyses which assume a continuous normal distribution. Also noted are interactive relationships…