Functional basic reading skills in Williams syndrome

Longitudinal Predictors of Word Reading for Children with Williams Syndrome

We examined the cognitive, language, and instructional predictors of early word-reading ability in a sample of children with Williams syndrome longitudinally. At Time 1, sixty-nine 6-7-year-olds (mean age = 6.53 years) completed standardized measures of phonological awareness, visual-spatial perception, vocabulary, and overall intellectual ability. Word-reading instruction type was classified as (systematic) Phonics (n = 35) or Other (n = 34). At Time 2, approximately three years later (mean age = 9.47 years), children completed a standardized assessment of single-word reading ability. Reading ability at Time 2 varied considerably, from inability to read any words to word-reading ability slightly above the level expected for age. The results of a multiple regression indicated that Time 1 word-reading instruction type, phonological awareness, and visual-spatial perception (as assessed by a matching letter-like forms measure) each explained significant unique variance in word reading at Time 2. A systematic phonics approach was associated with significantly better performance than other reading-instruction approaches. Exploratory analyses suggested that the relations between these factors were complex. Considered together, these findings strongly suggest that, in line with the Cumulative Risk and Resilience Model of reading disability, word-reading (dis)ability in Williams syndrome is probabilistic in nature, resulting from the interaction of multiple individual and environmental risk and protective factors. The results also have educational implications: Early word-reading instruction for children with Williams syndrome should combine systematic phonics and phonological awareness training while also incorporating letter discrimination instruction highlighting the visual-spatial differences between similar-appearing letters.

Spelling abilities of school-aged children with Williams syndrome

AIMS

We examined the relation between spelling ability and word-reading ability in children with Williams syndrome (WS).

METHODS

Eighty 9-17-year-olds with genetically-confirmed WS completed standardized tests of spelling, word reading, and intellectual ability; 45 also completed tests of phonological awareness and vocabulary. Reading instruction method was classified as Phonics or Other.

RESULTS

Spelling ability varied widely. Although at the group level, spelling standard scores (SSs) were significantly lower than word-reading SSs, at the individual level, this difference was significant for fewer than half the participants. Spelling and reading SSs were highly correlated, even after controlling for intellectual ability. Students taught to read using systematic phonics instruction had significantly higher spelling SSs than those taught to read using other approaches, even after controlling for intellectual ability. Spelling ability contributed significant unique variance to word-reading ability, beyond the effects of phonological awareness, vocabulary, and reading instruction method.

CONCLUSIONS

Our findings are consistent with Ehri's Word Identity Amalgamation Theory. In combination with previous meta-analytic findings for typically developing children (Graham & Santangelo, 2014) our results suggest that children with WS are likely to benefit from the inclusion of systematic spelling instruction as part of a systematic phonics approach to teaching word reading.

Factors Explaining Deficits in Reading Acquisition: The Case of Williams Syndrome

Purpose Multiple factors impact reading acquisition in individuals with reading disability, including genetic disorders such as Williams syndrome (WS). Despite a relative strength in oral language, individuals with WS usually have an intellectual disability and tend to display deficits in areas associated with reading. There is substantial variability in their reading skills. While some authors have postulated that phonological deficits are at the source of their reading deficits, others have suggested that they can be attributed to visuospatial deficits. This study was the first to undertake an in-depth exploration of reading skills among French-speaking children and adults with WS. We tested the assumption that some factors influence performance on single-word identification among individuals with WS, with a focus on the roles of phonological awareness and visuospatial skills. Method Participants were 29 French-speaking adults with WS and 192 controls matched for nonverbal mental age and reading level. We administered tests assessing reading (decoding and word recognition), vocabulary (expressive and receptive), and phonological and visuospatial skills. We also controlled for chronological age and nonverbal reasoning. Results Phonemic awareness was the most predictive factor of single-word identification in the WS group. Visuospatial skills also contributed, but not more or beyond other factors. More broadly, reasoning skills may also have accounted for the variability in single-word identification in WS, but this was not the case for either chronological age or vocabulary. Conclusions There is considerable heterogeneity among adults with WS, who may be either readers or prereaders. Similar profiles identified among individuals with other specific learning disabilities suggest that high reading variability is not specific to the neuropsychological profile of WS. We discuss a multidimensional approach to the factors involved in reading deficits in WS.

Concurrent predictors of word reading and reading comprehension for 9-year-olds with Williams syndrome

We examined the cognitive, language, and instructional factors associated with reading ability in Williams syndrome (WS). Seventy 9-year-olds with WS completed standardized measures of real-word reading, pseudoword decoding, reading comprehension, phonological skills, listening comprehension, nonverbal reasoning, visual-spatial ability, verbal working memory, rapid naming, and vocabulary. Reading instruction method was determined from school records and interviews with parents and teachers. Similar to prior findings for individuals with WS, reading ability varied widely, ranging from inability to read any words to reading comprehension at age level. Multiple regression analyses indicated that the primary concurrent predictor of word reading ability was reading instruction method, with a systematic phonics approach associated with considerably better performance than other reading instruction approaches. Phonological processing skills-as assessed by a composite of phonological awareness and verbal short-term memory-also contributed significant unique variance to word reading ability, as did visual-spatial ability. The concurrent predictors of reading comprehension were single-word reading and listening comprehension. These findings indicate that the factors that predict concurrent early word reading and reading comprehension abilities for children with WS are consistent with previous findings for typically developing children and that the Simple View of Reading applies to children with WS. Children with WS benefit strongly from systematic phonics instruction regardless of IQ. Instruction focused on improving listening comprehension is likely to improve reading comprehension, especially as word reading skills increase.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11145-021-10163-4.

Williams syndrome

Williams syndrome (WS) is a relatively rare microdeletion disorder that occurs in as many as 1:7,500 individuals. WS arises due to the mispairing of low-copy DNA repetitive elements at meiosis. The deletion size is similar across most individuals with WS and leads to the loss of one copy of 25-27 genes on chromosome 7q11.23. The resulting unique disorder affects multiple systems, with cardinal features including but not limited to cardiovascular disease (characteristically stenosis of the great arteries and most notably supravalvar aortic stenosis), a distinctive craniofacial appearance, and a specific cognitive and behavioural profile that includes intellectual disability and hypersociability. Genotype-phenotype evidence is strongest for ELN, the gene encoding elastin, which is responsible for the vascular and connective tissue features of WS, and for the transcription factor genes GTF2I and GTF2IRD1, which are known to affect intellectual ability, social functioning and anxiety. Mounting evidence also ascribes phenotypic consequences to the deletion of BAZ1B, LIMK1, STX1A and MLXIPL, but more work is needed to understand the mechanism by which these deletions contribute to clinical outcomes. The age of diagnosis has fallen in regions of the world where technological advances, such as chromosomal microarray, enable clinicians to make the diagnosis of WS without formally suspecting it, allowing earlier intervention by medical and developmental specialists. Phenotypic variability is considerable for all cardinal features of WS but the specific sources of this variability remain unknown. Further investigation to identify the factors responsible for these differences may lead to mechanism-based rather than symptom-based therapies and should therefore be a high research priority.

A cross-comparison of cognitive ability across 8 genomic disorders

Genomic disorders result from rearrangement of the human genome. Most genomic disorders are caused by copy number variants (CNV), deletions or duplications of several hundred kilobases. Many CNV loci are associated with autism, schizophrenia, and most commonly, intellectual disability (ID). However, there is little comparison of cognitive ability measures across these CNV disorders. This study aims to understand whether existing data can be leveraged for a cross-comparison of cognitive ability among multiple CNV. We found there is a lack of harmonization among assessment instruments and little standardization for reporting summary data across studies. Despite these limitations, we identified a differential impact of CNV loci on cognitive ability. Our data suggest that future cross-comparisons of CNV disorders will reveal meaningful differences across the phenotypic spectrum, especially if standardized phenotypic assessment is achieved.