In this commentary, I highlight key insights from research on learning disabilities (LD) reported in this special issue. Authors of each article describe innovative work that is expanding frontiers of LD knowledge, by focusing on vulnerable and understudied populations, using multiple methodologies and data sources, and building and refining…

Cross-syndrome comparisons offer an important window onto understanding heterogeneity in mathematical learning disabilities or dyscalculia. The present study therefore investigated symbolic numerical magnitude processing in two genetic syndromes that are both characterized by mathematical learning disabilities: Turner syndrome and 22q11.2 deletion…

Verbal--spatial discrepancies are common in healthy individuals and in those with neurodevelopmental disorders associated with cognitive control deficits including: Autism Spectrum Disorder, Non-Verbal Learning Disability, Fragile X, 22q11 deletion, and Turner Syndrome. Previous data from healthy individuals suggest that the magnitude of the…

An increasing number of children are likely to have a known genetic cause for their special educational needs. One such genetic condition is 22q11.2 deletion syndrome (22qDS), a genetic syndrome associated with early speech and language difficulties, global and specific cognitive impairments, difficulties with attention and difficulties with…

We examined whether "discrete trial training" (DTT) could be used to identify learning impairments in mathematical reasoning in boys with fragile X syndrome (FXS). Boys with FXS, aged 10-23 years, and age and IQ-matched controls, were trained to match fractions to pie-charts and pie-charts to decimals either on a computer or with a…

Visual and auditory verbal learning using a selective reminding format was studied in a mixed clinical sample of children with autism spectrum disorder (ASD) (n = 42), attention-deficit hyperactivity disorder (n = 83), velocardiofacial syndrome (n = 17) and neurotypicals (n = 38) using the Test of Memory and Learning to (1) more thoroughly…

Velocardiofacial syndrome (VCFS), also known as DiGeorge, conotruncal anomaly face, and Cayler syndromes, is caused by a microdeletion in the long arm of Chromosome 22. We review the history of the syndrome from the first clinical reports almost half a century ago to the current intriguing molecular findings associating genes from the…

Aim: Mutations in the "SLC16A2" gene have been implicated in Allan-Herndon-Dudley syndrome (AHDS), an X-linked learning disability syndrome associated with thyroid function test (TFT) abnormalities. Delayed myelination is a non-specific finding in individuals with learning disability whose genetic basis is often uncertain. The aim of this study…

Background: Our previous investigation found that the same genes influence poor reading and mathematics performance in 10-year-olds. Here we assess whether this finding extends to language and general cognitive disabilities, as well as replicating the earlier finding for reading and mathematics in an older and larger sample. Methods: Using a…

Understanding the precursors and early indicators of dyslexia is key to early identification and effective intervention. Now there's a single research volume that brings together the very latest knowledge on the earliest stages of dyslexia and the diverse genetic, neurobiological, and cognitive factors that may contribute to it. Based on findings…

Background: To what extent do genetic and environmental influences on reading disability overlap with those on mathematics disability? Multivariate genetic research on the normal range of variation in unselected samples has led to a Generalist Genes Hypothesis which posits that the same genes largely affect individual differences in these…

Recognized as the definitive reference in the field, this book addresses a broad range of biologically based disorders that affect children's learning and development. Leading authorities review the genetics of each disorder; its course and outcome; associated developmental, cognitive, and psychosocial challenges; and what clinicians and educators…

Williams syndrome is a rare neurodevelopmental disorder caused by deletion of approximately 25 genes on chromosome 7q11.23. Children with the syndrome evidence large individual differences in both broad language and reading abilities. Nevertheless, as a group, children with this syndrome show a consistent pattern characterized by relative…

Current neurocognitive theories of number processing [Dehaene, S., Piazza, M., Pinel, P., & Cohen, L. (2003). Three parietal circuits for number processing. "Cognitive Neuropsychology," 20, 487-506] state that mathematical performance is made possible by two functionally and anatomically distinct subsystems of number processing: a verbal system…

Background: Learning disabilities are one of the most consistently reported features in Velo-Cardio-Facial Syndrome (VCFS). Earlier reports on IQ in children with VCFS were, however, limited by small sample sizes and ascertainment biases. The aim of the present study was therefore to replicate these earlier findings and to investigate intellectual…