A Genetic Basis Of Chinese Children's Reading Ability

Developmental dyslexia refers to the phenomenon that children with normal intelligence have no obvious neurological or organic damage during the development process,but their reading level lags significantly behind their corresponding intellectual level or physiological age.Developmental dyslexia has been widely accepted as a type of learning disorder that is caused by genetic defects in neurodevelopmental abnormalities that lead to cognitive impairment and eventually lags in reading behavior,accounting for about 5-10%of children.Previous research on cognitive impairment of dyslexia has found that phonological deficits(phonological awareness and naming speed)are the core cognitive deficits of dyslexia.But what is the genetic basis of reading ability?How do genetic factors affect reading level through phonological deficits?These issues have just caught attention.In 2019,researchers in Europe and researchers in the United States studied the genetic basis of the phonetic abilities of European and American children whose mother tongue is alphabetic writing,respectively,through genome-wide association study(GWAS).The purpose of this study was to explore the genetic basis of the reading ability of Chinese-speaking Chinese children with a whole-genome association analysis and to verify whether these genetic loci can further explain children's reading ability.In this study,the participants were 888 primary school students of grade 3-4 in Xi'an.The first part of the study measured the behavioral data of the participants,which included phoneme deletion task,onset and rime deletion task,rapid naming,reading fluency task and Chinese characters recognition.Then,we analyzed the correlation between different task performances,and used factor analysis on some phenotypes related to cognitive function.In the second part of the study,genotyping with SNP chip was carried out for the participants.After genotyping,the behavioral data of the first part were taken as quantitative trait during genome-wide association study to find SNP related to each phenotype.In the third part of the study,the relationship between genetic markers,cognitive function and behavioral performance was studied.The results show that:(1)there were differences in the results of different types of behavioral scales of Chinese children in grades 3-4,and there was a strong correlation between these behavioral data.The results of factor analysis also revealed the different types of cognitive function represented by phenotypes.(2)Through genome-wide association study,five SNPs were found significantly related to two rapid naming tasks(dice&picture)and phoneme deletion tasks:rs 145064802 related to dice rapid naming task,rs 150499945 related to picture rapid naming task,rs10962094 related to phoneme deletion and factor 2(including phoneme deletion task and onset and rime deletion task),rs 1953413 related to factor 1(including four tasks of rapid naming),rs77519418 related to factor 2(including phoneme deletion task and onset and rime deletion task).(3)At the same time,these SNPs could be used to classify the behavior corresponding to cognitive function in different degrees,which verified the relationship among these three.The conclusions are as follows:(1)phoneme deletion task,onset and rime deletion task,rapid naming task,Chinese characters recognition task and reading fluency task could reflect the reading performance of grade 3-4 primary school students from different aspects,and there was a certain correlation between these tasks.(2)Through genome-wide association study,five significant SNPs were found in two rapid naming tasks(dice,picture),phoneme deletion tasks and two factor analysis scores.(3)The SNPs could be embraced in the model of physiological indicators,cognition and behavior symptoms.