Fig. 6. cis-regulatory down-regulation of the benthic allele of Bmp6 in late, not early, stages of tooth development. Shown are the ratios of benthic to marine alleles measured by pyrosequencing assays from either genomic DNA (light gray) or tooth plate cDNA (dark gray) from benthic × marine F1 hybrids at three different developmental stages. No significant difference in Bmp6 expression was detected between marine and benthic alleles at the larval stage, but at the juvenile and adult stage the benthic allele was significantly down-regulated (sample sizes and P values by the Wilcoxon signed rank test for early, juvenile, and adult are n = 12, P = 0.38; n = 18, P = 0.0003; and n = 13, P = 0.0005, respectively). Error bars are SEM.

No abstract

Children at risk for familial dyslexia (n = 107) and their controls (n = 93) have been followed from birth to school entry in the Jyvaskyla Longitudinal study of Dyslexia (JLD) on developmental factors linked to reading and dyslexia. At the point of school entry, the majority of the at-risk children displayed decoding ability that fell at least 1 SD below the mean of the control group. Measures of speech processing were the earliest indices to show both group differences in infancy and also significant predictive associations with reading acquisition. A number of measures of language, including phonological and morphological skill collected repeatedly from age three, revealed group differences and predictive correlations. Both the group differences and the predictive associations to later language and reading ability strengthened as a function of increasing age. The predictions, however, tend to be stronger and the spectrum of significant correlations wider in the at-risk group. These results are crucial to early identification and intervention of dyslexia in at-risk children.

No abstract

A specific learning disability, developmental dyslexia, is a language-based disorder that is shown to be strongly familial. Therefore, infants born to families with a history of the disorder are at an elevated risk for the disorder. However, little is known of the potential early markers of dyslexia. Here we report differences between 6-month-old infants with and without high risk of familial dyslexia in brain electrical activation generated by changes in the temporal structure of speech sounds, a critical cueing feature in speech. We measured event-related brain responses to consonant duration changes embedded in ata pseudowords applying an oddball paradigm, in which pseudoword tokens with varying /t/ duration were presented as frequent standard (80%) or as rare deviant stimuli (each 10%) with an interval of 610 msec between the stimuli. The infants at risk differ from control infants in both their initial responsiveness to sounds per se and in their change-detection responses dependent on the stimulus context. These results show that infants at risk due to a familial background of reading problems process auditory temporal cues of speech sounds differently from infants without such a risk even before they learn to speak.