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When dyslexia is diagnosed late, the question is whether this is due to late-emerging (LE) or late-identified (LI) problems. In a random selection of dyslexia-diagnosis case files we distinguished early-diagnosed (Grade 1–3, n = 116) and late-diagnosed (Grade 4–6) dyslexia. The late-diagnosed files were divided into LE (n = 54) and LI dyslexia (n = 45). The LE group consisted of children whose national-curriculum literacy outcomes did not warrant referral for dyslexia diagnosis in Grades 1–2; the LI group of children whose literacy outcomes did, but who were referred for diagnostic assessment after Grade 3. At the time of diagnosis, the percentage of poor performers on word-level literacy measures generally did not differ between the groups. Only the LE group contained fewer poor performers than the early-diagnosed and LI group on some word-reading measures. All groups showed similar distributions of phonological difficulties. There were no indications of compensation through vocabulary, memory or IQ in either late-diagnosed group. Our diagnosis-based study confirms and extends previous research-based studies on LE dyslexia. Moreover, it shows that LI dyslexia exists, which can be regarded as the existence of instructional casualties. The findings speak to issues of identification, diagnosis and compensation and call for further efforts to improve the early identification of dyslexia.

The assumption that statistical learning is affected in dyslexia has generally been evaluated in children and adults with diagnosed dyslexia, not in pre-literate children with a family risk (FR) of dyslexia. In this study, four-to-five-year-old FR children (n = 25) and No-FR children (n = 33) completed tasks of emerging literacy (phoneme awareness and RAN). They also performed an online non-adjacent dependency learning (NADL) task, based on the Serial Reaction Time (SRT) task paradigm. Children's accuracy (hits), signal sensitivity (d′) and reaction times were measured. The FR group performed marginally more poorly on phoneme awareness and significantly more poorly on RAN than the No-FR group. Regarding NADL outcomes, the results were less straightforward: the data suggested successful statistical learning for both groups, as indicated by the hit and reaction time curves found. However, the FR group was less accurate and slower on the task than the No-FR group. Furthermore, unlike the No-FR group, performance in the FR group varied as a function of the specific stimulus presented. Taken together, these findings fail to show a robust difference in statistical learning between children with and without an FR of dyslexia at preschool age, in line with earlier work on older children and adults with dyslexia.