title: Impact of parental history of myopia on the development of myopia in mainland china school-aged children.
abstract: BACKGROUND
  Myopia is a very common condition and a significant public health problem in China. The objective of the study was to explore the genetic influence on myopia in Mainland China school-aged children in Beijing.
  
  
  METHODS
  In 2008, the data from 15,316 Chinese school students aged 6-18 years from 19 randomized schools in Beijing were analyzed to evaluate genetic influence on myopia in children. Heritability was calculated by mid-parent-offspring regression and parent-offspring regression.
  
  
  RESULTS
  The estimate of heritability was 0.30 (95% CI, 0.27-0.33) for refractive value (RV). The adjusted mean refractive error was -2.33D (95% CI, -2.45 to -2.21) in children with two myopic parents compared with -1.13D (95% CI, -1.78 to -1.08) in children with no parental myopia. The adjusted odds ratio (OR) was 2.83 (95% CI, 2.47-3.24) in children with two myopic parents compared with no parental myopia.
  
  
  CONCLUSIONS
  The study found a strong association between parental history of myopia and genesis of myopia in the offspring even after adjusting for environmental factors.
authors.affiliation: Tennent Institute of Ophthalmology, Gartnavel General Hospital, Glasgow, UK.
authors.forename: Lik Thai
authors.initials: LT
authors.lastname: Lim
authors.affiliation: School of Social Development and Public Policy, Beijing Normal University, Beijing, China.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Gong
authors.affiliation: University of Glasgow School of Medicine, University Avenue, Glasgow, UK.
authors.forename: Elliott Y
authors.initials: EY
authors.lastname: Ah-Kee
authors.affiliation: Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Gexin
authors.initials: G
authors.lastname: Xiao
authors.affiliation: School of Social Development and Public Policy, Beijing Normal University, Beijing, China.
authors.forename: Xiulan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Shicheng
authors.initials: S
authors.lastname: Yu
keywords: epidemiology; myopia; parental history