Functional basic reading skills in Williams syndrome

ABSTRACT

This study investigated whether individuals with Williams syndrome (WS) can attain a functional level of basic reading skills. The Study also investigated broader cognitive factors associated with reading ability in individuals with WS. Thirty individuals with WS participated in this study (mean chronological age 21 years and mean mental age 7 years 7 months). The results supported our hypotheses that: firstly, reading abilities would be heterogeneous in WS; secondly, at least some WS individuals are capable of achieving a functional basic reading level; and thirdly, on average, WS individuals would find reading of nonwords more difficult than reading of regular and irregular words. Moreover, higher reading ability was found to be associated with increased outcomes in adaptive functioning, in particular, Written and Expressive Communication skills and Community Living skills, highlighting the potential benefits of developing reading abilities in WS. Although Intelligence Quotient (IQ) was related to overall basic reading ability generally, it was not found to be a determining factor in reading subtypes. Several cognitive skills known to be related to reading ability in typically developing individuals were found to be associated with reading performance and reading subtypes. Implications for appropriate reading instruction are discussed.

Acknowledgments

Thank you to WS families and Williams Syndrome Australia Limited who funded this work.

Notes

¹ An aim of the current study was to determine whether individuals with WS are ‘functionally literate’, in that they have achieved a level of basic reading ability necessary to participate and function reasonably independently within the community. As noted by Wheldall and Watkins (2004), the term functional literacy is difficult to define and there has been little consensus in the literature regarding a level of reading performance at which individuals would be considered functionally literate. Goyen (1977, as cited in Wheldall & Watkins, 2004) estimated a functional level of literacy as being equivalent to a reading performance of around a 10 to 11 year old (which is achieved by end of Year 5 for most Australian students). The oldest age band from the CC2 norms was considered the closest to an end of Year 5 level of schooling and representative of a functional level of literacy and used to evaluate WS participants whose chronological age fell outside of the CC2’s norm range.

² The nonreaders in this study were both females and similarly aged (32y 10m and 33y and 7m) and therefore well past the age of reading acquisition. One had a 1.8Mb deletion and one had the common ~1.6Mb WS deletion. They had a similar level of intellectual functioning and did not have the lowest IQ scores in the group (GIA or IQ was 67 and 65, respectively).

³ For comparisons with regular words and irregular words, two participants had a 1.8Mb deletion.

⁴ Since regular words can be read by either the lexical or nonlexical route, they were not relevant for this analysis.

⁵ Note that two individuals (Identification numbers 13 and 15 in Table 7) did not fit the criteria exactly for the Lexical Readers subgroup, but this group was the closest fit that could be found to place them in.

⁶ To determine whether there was a significant difference in reading abilities between the individuals with the typical deletion and those with an atypical deletion, individual matched pairs were created. Each individual with an atypical deletion was matched to a participant with a typical deletion on the basis of their gender, chronological age (CA), mental age (MA), and intellectual functioning GIA (IQ). Paired sample t-tests confirmed there was no significant difference between the matched pairs for CA [t(7) = −1.14, p = .290, Typical Mean = 22.42 years (SD = 8.40 years), Atypical Mean = 24.31 years (SD = 7.94)]. There was also no significant difference for MA [t(7) = –.199, p = .848, Typical Mean = 7.77 years (SD = 2.01), Atypical Mean = 7.99 years (SD = 2.06)] or GIA [t(7) = −1.39, p = .207, Typical Mean = 66.88 (SD = 18.87), Atypical Mean = 67.38 (SD = 15.91)].

Additional information

Funding

This work was supported by the Williams Syndrome Australia Limited [9201201019] and a research grant from the Jerome Lejeune Foundation;