Reading and Writing: An Interdisciplinary Journal 15: 433–437, 2002.
© 2002 Kluwer Academic Publishers. Printed in the Netherlands.
MARGARET J. SNOWLING
& JEAN-EMILE GOMBERT
University of York, UK;
University of Rennes 2, France
In recent years, a vast amount of evidence has accumulated on children’s
reading development. Indeed, it is fair to say that the process of learning to
read is sufﬁciently understood to inform educational practice. However, there
is still a paucity of research on the reading skills of children of low cognitive
ability who arguably are most in need of skilled teaching. These children
are described in the USA as having mental retardation (DSM-IV) and in
UK/Europe as having Special Educational Needs because of their Learning
Difﬁculties (ICD-10). Ironically, although there is only a weak correlation
between reading skills and IQ (Siegel 1993), the problems that children with
learning difﬁculties have with the acquisition of literacy are commonly attrib-
uted to their low intelligence. The striking case of ‘hyperlexia’, children who
decode well in advance of expectation based on mental age (Nation 1999),
underlines the fact that low IQ is not an explanation for reading failure. It
is therefore important for researchers to address how individual differences
in cognitive and linguistic skills in atypical populations can account for the
considerable variation in literacy skills that is observed in these groups.
This special issue brings together papers on the language and reading
skills of persons with neuro-developmental disorders, speciﬁcally, Down
syndrome and Williams syndrome. Both syndromes are due to chromo-
somal abnormalities and, although genetic, are not usually inherited. Down
syndrome is the commoner of the two syndromes, occurring in about 1.5 per
1,000 births usually associated with Trisomy 21. Williams syndrome is much
rarer, affecting 1 in 20,000 live births and resulting from a micro-deletion on
chromosome 7. Children who are born with these chromosomal abnormalities
typically are of low IQ (full scales IQs in the range 40–60), but they often
show an uneven cognitive proﬁle as the current set of papers makes clear.
The issue begins with papers focussing on aspects of reading in Down
syndrome. The provocative claim made by Cossu & Marshall (1990) that
phonological awareness is not a pre-requisite for learning to read (among
children with Down syndrome) is refuted by the ﬁrst three papers. Cardoso-
Martins, Michalick and Pollo (pp. 439–454) studied a population of Brazilian
children and adults with Down syndrome, 39 readers and 30 non-readers.