BackgroundThis study considers the role of early speech difficulties in literacy development, in the context of additional risk factors.MethodChildren were identified with speech sound disorder (SSD) at the age of 3½ years, on the basis of performance on the Diagnostic Evaluation of Articulation and Phonology. Their literacy skills were assessed at the start of formal reading instruction (age 5½), using measures of phoneme awareness, word‐level reading and spelling; and 3 years later (age 8), using measures of word‐level reading, spelling and reading comprehension.ResultsThe presence of early SSD conferred a small but significant risk of poor phonemic skills and spelling at the age of 5½ and of poor word reading at the age of 8. Furthermore, within the group with SSD, the persistence of speech difficulties to the point of school entry was associated with poorer emergent literacy skills, and children with ‘disordered’ speech errors had poorer word reading skills than children whose speech errors indicated ‘delay’. In contrast, the initial severity of SSD was not a significant predictor of reading development. Beyond the domain of speech, the presence of a co‐occurring language impairment was strongly predictive of literacy skills and having a family risk of dyslexia predicted additional variance in literacy at both time‐points.ConclusionsEarly SSD alone has only modest effects on literacy development but when additional risk factors are present, these can have serious negative consequences, consistent with the view that multiple risks accumulate to predict reading disorders.

A significant proportion of children (up to 7% in the UK) present with pronounced language difficulties that cannot be explained by obvious causes like other neurological and medical conditions. A substantial genetic component is predicted to underlie such language problems. Copy number variants (CNVs) have been implicated in neurodevelopmental and psychiatric conditions, such as autism and schizophrenia, but it is not fully established to what extent they might contribute to language disorders. We conducted a CNV screen in a longitudinal cohort of young children with language-related difficulties (n = 85), focusing on single events at candidate loci. We detected a de novo deletion on chromosome 15q13.1–13.3. The adjacent 15q11-13.1 locus is disrupted in Prader-Willi and Angelman syndromes, while disruptions across the breakpoints (BP1-BP6) have previously been implicated in different neurodevelopmental phenotypes including autism, intellectual disability (ID), seizures and developmental delay (DD). This is the first report of a deletion at BP3-BP5 being linked to a deficit confined to language impairment, in the absence of ID, expanding the range of phenotypes that implicate the chromosome 15q13 locus.

Twin studies indicate that dyscalculia (or mathematical disability) is caused partly by a genetic component, which is yet to be understood at the molecular level. Recently, a coding variant (rs133885) in the myosin-18B gene was shown to be associated with mathematical abilities with a specific effect among children with dyslexia. This association represents one of the most significant genetic associations reported to date for mathematical abilities and the only one reaching genome-wide statistical significance. We conducted a replication study in different cohorts to assess the effect of rs133885 maths-related measures. The study was conducted primarily using the Avon Longitudinal Study of Parents and Children (ALSPAC), (N = 3819). We tested additional cohorts including the York Cohort, the Specific Language Impairment Consortium (SLIC) cohort and the Raine Cohort, and stratified them for a definition of dyslexia whenever possible. We did not observe any associations between rs133885 in myosin-18B and mathematical abilities among individuals with dyslexia or in the general population. Our results suggest that the myosin-18B variant is unlikely to be a main factor contributing to mathematical abilities.

In the absence of criteria for the diagnosis of dyslexia, considerable weight is given to self‐report, in particular in studies of children at family risk of dyslexia. The present paper uses secondary data from a previous study to compare parents who self‐report as dyslexic and those who do not, in relation to objectively determined levels of ability. In general, adults are more likely to self‐report as ‘dyslexic’ if they have poorer reading and spelling skills and also if there is a discrepancy between IQ and measured literacy. However, parents of higher social status who have mild literacy difficulties are more likely to self‐report as dyslexic than parents who have weaker literacy skills but are less socially advantaged. Together the findings suggest that the judgement as to whether or not a parent considers themselves ‘dyslexic’ is made relative to others in the same social sphere. Those who are socially disadvantaged may, in turn, be less likely to seek support for their children. Â © 2014 The Authors Dyslexia Published by John Wiley & Sons Ltd.

These data show that although the GAPS test can be used by a range of people who work with young children, it is not a sensitive screener for language impairment when used by trained researchers.