High heritability of myopia does not preclude rapid changes in prevalence

Abstract

The aetiology of myopia is complex, but the major form of myopia results from an interplay between genetic factors and environmental influences. Although there are clear patterns of family inheritance and high heritability values in studies from all over the world,environmental factors are increasingly important in determining myopic outcomes in East Asia, and perhaps elsewhere. This is not paradoxical, as high heritability does not preclude strong environmental influences. The lower heritability values obtained from parent-offspring correlations in populations of East Asian origin where there are marked differences in the environmental exposures (education and urbanization) of parents and children, and where there has been a major shift in the population distribution of myopia, are consistent with this view. Despite the impact of environmental pressures in East Asia, there is evidence that parental myopia influences the position of their offspring within that new population distribution.

Familial aggregation of myopia in the Tehran eye study: estimation of the sibling and parent offspring recurrence risk ratios

“…Findings from the Framingham Offspring Eye Study Group also showed that myopia was less aggregated in siblings with a larger age difference 42. Like many others, we showed a strong association between education and the prevalence of myopia 4 19 – 20. However, it remains unclear whether educational level is an independent risk factor or a surrogate for close up work or some other socioeconomic characteristic 20 – 21.…”

“…The familial aggregation found in this study was greater among siblings than between parents and offspring. Similarly, the familial occurrence of myopia has been noted by several investigators to be greatest between siblings and less between parents and offspring 2 – 4. This suggests that shared environmental factors could be important in the aggregation of myopia 29.…”

Familial aggregation of myopia in the Tehran eye study: estimation of the sibling and parent offspring recurrence risk ratios

“…Findings from the Framingham Offspring Eye Study Group also showed that myopia was less aggregated in siblings with a larger age difference 42. Like many others, we showed a strong association between education and the prevalence of myopia 4 19 – 20. However, it remains unclear whether educational level is an independent risk factor or a surrogate for close up work or some other socioeconomic characteristic 20 – 21.…”

“…The familial aggregation found in this study was greater among siblings than between parents and offspring. Similarly, the familial occurrence of myopia has been noted by several investigators to be greatest between siblings and less between parents and offspring 2 – 4. This suggests that shared environmental factors could be important in the aggregation of myopia 29.…”

Prevalence of Refractive Errors in a Brazilian Population: The Botucatu Eye Study

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Genetic prediction of myopia: prospects and challenges

“…To illustrate the first point mentioned above, Figure shows the relationship between the refractive error of parents and their children using computer simulations performed under the assumption that refractive error is a purely polygenic trait (details of the simulation parameters are available from the authors on request). For heritability values across the range 25–75%, which is typical of the range reported for refractive error and myopia . it is evident that while the mean refractive error of parents is a good predictor of the average refractive error of their children (blue line of best fit in the graphs) it is only a crude guide to the refractive error of individual children.…”

Familial aggregation of myopia in the Tehran eye study: estimation of the sibling and parent offspring recurrence risk ratios

“…Findings from the Framingham Offspring Eye Study Group also showed that myopia was less aggregated in siblings with a larger age difference 42. Like many others, we showed a strong association between education and the prevalence of myopia 4 19 – 20. However, it remains unclear whether educational level is an independent risk factor or a surrogate for close up work or some other socioeconomic characteristic 20 – 21.…”

“…The familial aggregation found in this study was greater among siblings than between parents and offspring. Similarly, the familial occurrence of myopia has been noted by several investigators to be greatest between siblings and less between parents and offspring 2 – 4. This suggests that shared environmental factors could be important in the aggregation of myopia 29.…”

Prevalence of Refractive Errors in a Brazilian Population: The Botucatu Eye Study

“……”

Genetic prediction of myopia: prospects and challenges

“…To illustrate the first point mentioned above, Figure shows the relationship between the refractive error of parents and their children using computer simulations performed under the assumption that refractive error is a purely polygenic trait (details of the simulation parameters are available from the authors on request). For heritability values across the range 25–75%, which is typical of the range reported for refractive error and myopia . it is evident that while the mean refractive error of parents is a good predictor of the average refractive error of their children (blue line of best fit in the graphs) it is only a crude guide to the refractive error of individual children.…”

Familial aggregation of myopia in the Tehran eye study: estimation of the sibling and parent offspring recurrence risk ratios

“…Findings from the Framingham Offspring Eye Study Group also showed that myopia was less aggregated in siblings with a larger age difference 42. Like many others, we showed a strong association between education and the prevalence of myopia 4 19 – 20. However, it remains unclear whether educational level is an independent risk factor or a surrogate for close up work or some other socioeconomic characteristic 20 – 21.…”

“…The familial aggregation found in this study was greater among siblings than between parents and offspring. Similarly, the familial occurrence of myopia has been noted by several investigators to be greatest between siblings and less between parents and offspring 2 – 4. This suggests that shared environmental factors could be important in the aggregation of myopia 29.…”

Prevalence of Refractive Errors in a Brazilian Population: The Botucatu Eye Study

“……”

Genetic prediction of myopia: prospects and challenges

“…To illustrate the first point mentioned above, Figure shows the relationship between the refractive error of parents and their children using computer simulations performed under the assumption that refractive error is a purely polygenic trait (details of the simulation parameters are available from the authors on request). For heritability values across the range 25–75%, which is typical of the range reported for refractive error and myopia . it is evident that while the mean refractive error of parents is a good predictor of the average refractive error of their children (blue line of best fit in the graphs) it is only a crude guide to the refractive error of individual children.…”