Abstract
Purpose:
To provide accurate estimates of the heritabilities and intraclass correlations among different family types regarding a range of refractive errors and ocular biometrics in Korean population.
Methods:
We studied participants in the Healthy Twin Study, a prospective cohort study that has recruited Korean adult twins and their family members. Refraction, corneal topography, and A-scan ultrasonography were assessed. To see the degree of resemblance among different types of family relationships, intraclass correlation coefficients (ICC) were calculated. Variance-component methods were applied to estimate the genetic contributions to eye phenotypes as heritability based on the maximum likelihood estimation. Narrow sense heritability was calculated as the proportion of the total phenotypic variance explained by additive genetic effects, and linear and non-linear effects of age, sex, and interactions between age and sex were adjusted.
Results:
ICCs for spherical equivalent from monozygotic twins, pooled first degree pairs, and spouse pairs were 0.85, 0.31 and 0.07, respectively. The ICCs of other ocular biometrics were also significantly higher in monozygotic twins compared to other relative pairs, with greater consistency and conformity. The estimated narrow sense heritability (95% CI) was 0.78 (0.71-0.84) for spherical equivalent, 0.86 (0.82-0.90) for axial length, 0.83 (0.76-0.91) for anterior chamber depth, and 0.70 (0.63-0.77) for corneal astigmatism.
Conclusions:
The estimated heritability of spherical equivalent and ocular biometrics in the Korean population suggests the compelling evidence that all traits are highly heritable.
Keywords: 605 myopia •
539 genetics