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Abstract #18175 Published in IGR 9-2
The inheritance of peripapillary atrophy
Healey PR; Mitchell P; Gilbert CE; Lee AJ; Ge D; Snieder H; Spector TD; Hammond CJInvestigative Ophthalmology and Visual Science 2007; 48: 2529-2534
PURPOSE: To estimate the relative importance of genes and environment in peripapillary atrophy type β (β-PPA) in a classic twin study. METHODS: Female twin pairs (n = 506) aged 49 to 79 years were recruited from the St. Thomas' UK Adult Twin Registry. Peripapillary atrophy was identified from masked grading of stereoscopic optic disc photographs. Structural equation modeling was performed using Mx with polychoric correlations of β-PPA and refractive error (divided into deciles). RESULTS: β-PPA prevalence was 25.1% and did not vary with zygosity. Case-wise concordance for right eyes was 0.76 (95% CI, 0.57-0.88) for monozygotic (MZ) and 0.37 (95% CI, 0.15-0.56) for dizygotic (DZ) pairs. Multivariate modeling suggested additive genetic effects and individual environment, with no shared environment or dominant genetic effect. β-PPA heritability was 0.70 (95% CI, 0.54-0.83), and spherical equivalent 0.88 (95% CI, 0.85-0.91); age had no significant effect on variance. The genetic correlation between β-PPA and spherical equivalent was -0.21. However, only 3% of the genetic variance of β-PPA was explained by genetic factors in common with refractive error, with 67% explained by specific genetic factors for β-PPA. Of the 30% of variance explained by unique environmental factors, only 3% was explained by these factors in common with environmental factors involved in refractive error. CONCLUSIONS: The presence of β-PPA, a frequent ocular finding known to be associated with open-angle glaucoma, appears to be under strong genetic control, with only a small amount of this genetic effect shared with genes involved in myopia.
Dr. P.R. Healey, Centre for Vision Research, University of Sydney, Australia. phealey@glaucoma.net.au
Classification:
2.12 Choroid, peripapillary choroid, peripapillary atrophy (Part of: 2 Anatomical structures in glaucoma)
1.2 Population genetics (Part of: 1 General aspects)
