This paper reports the literacy skills of 63 children selected as being at genetic risk of dyslexia
compared with 34 children from families reporting no history of reading impairment. Fifty-seven per cent of the at-risk group were delayed in literacy development at 6 years compared
with only 12% of controls. The “unimpaired” at-risk group were not statistically different
from controls on most cognitive and language measures at 45 months, whereas the literacy-delayed group showed significantly slower speech and language development, although they
did not differ from controls in nonverbal ability. Letter knowledge at 45 months was the
strongest predictor of literacy level at 6 years. In addition, early speech and language skills
predicted individual differences in literacy outcome and genetic risk accounted for unique
variance over and above these other factors. The results are discussed in terms of an
interactive developmental model in which semantic and phonological skills support early
reading acquisition.