Table of Contents

ABSTRACT

Background: Developmental dyslexia (DD) is the most common learning disability worldwide. A ROBO1 polymorphism, rs6803202, was found to be correlated with the short-term memory of meaningful verbal sequences and was associated with DD. However, the results were not consistent, and most of the studies were only done in Caucasians but not in Chinese, and different genetic background might exist between Caucasians and Chinese. Moreover, DD is a common learning disorder in Hong Kong children, with a prevalence rate up to 12.6%. Thus, it is worthwhile to study the association between rs6803202 and DD in Hong Kong Chinese children.

Methods: DNA was extracted from saliva samples of 107 dyslexic children and 95 ethnicity-matched control subjects. Genotyping of rs6803202 was carried out with real-time PCR using TaqMan probes.

Results: The C allele of rs6803202 was associated with DD after controlling for the effect of gender (adjusted P-value = 0.014, OR = 1.65). Genotypes containing the C allele were also associated with DD (adjusted P-value = 0.013, OR = 2.32).

Conclusions: Association was found between the ROBO1 polymorphism rs6803202 and DD in southern Chinese children. However, the association should be validated by further studies due to the limited sample size of this study.

Keywords: developmental dyslexia (DD), Hong Kong Chinese children, ROBO1 gene, susceptibility gene, case-control association study