An international team of scientists from the United Kingdom, the United States, and Sweden has used a genetic scoring technique to predict reading performance throughout school years from DNA alone.
Calculating an individual’s GPS requires information from a genome-wide association study that finds specific genetic variants linked to particular traits. Image credit: Alexas Fotos.
Led by Saskia Selzam, a Ph.D. candidate in social genetic and developmental psychiatry at King’s College London, UK, the study shows that a genetic score comprising around 20,000 of DNA variants explains five per cent of the differences between children’s reading performance.
Students with the highest and lowest genetic scores differed by a whole two years in their reading performance.
These findings highlight the potential of using genetic scores to predict strengths and weaknesses in children’s learning abilities.
“These scores could one day be used to identify and tackle reading difficulties early, rather than waiting until children develop these problems at school,” Selzam and co-authors said.
The scientists calculated genetic scores for educational achievement in 5,825 individuals from the Twins Early Development Study (TEDS) based on genetic variants identified to be important for educational attainment.
They then mapped these scores against reading ability between the ages of seven and 14.
“It is now possible to create individual-specific genetic scores, called genome-wide polygenic scores (GPS),” they explained.
“We used a GPS for years of education to predict reading performance assessed at UK National Curriculum Key Stages 1 (age 7), 2 (age 12) and 3 (age 14) and on reading tests administered at ages 7 and 12 in a UK sample of 5,825 unrelated individuals.”
Genetic scores were found to explain up to 5% of the differences between children in their reading ability.
This association remained significant even after accounting for cognitive ability and family socio-economic status.
“Although 5% may seem a relatively small amount, this is substantial compared to other results related to reading,” the authors said.
“For example, gender differences have been found to explain less than 1% of the differences between children in reading ability.”
“The value of polygenic scores is that they make it possible to predict genetic risk and resilience at the level of the individual,” Selzam added.
“This is different to twin studies, which tell us about the overall genetic influence within a large population of people.”
“We think this study provides an important starting point for exploring genetic differences in reading ability, using polygenic scoring. For instance, these scores could enable research on resilience to developing reading difficulties and how children respond individually to different interventions.”
“We hope these findings will contribute to better policy decisions that recognize and respect genetically driven differences between children in their reading ability,” said study senior author Professor Robert Plomin, also from King’s College London.
The findings were published online this week in the journal Scientific Studies of Reading.
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Saskia Selzam et al. Genome-Wide Polygenic Scores Predict Reading Performance Throughout the School Years. Scientific Studies of Reading, published online March 28, 2017; doi: 10.1080/10888438.2017.1299152
