Heritability analysis of spherical equivalent, axial length, corneal curvature, and anterior chamber depth in the Beaver Dam Eye Study.
OBJECTIVE
To examine genetic influences for quantitative refraction. Spherical equivalent and its related binary traits of myopia and hyperopia are highly correlated within families. Many linkage regions have been reported for myopia, high myopia, and quantitative refraction. However, the measured phenotype of spherical equivalent is in large part dictated by the relationship between the underlying optical components of axial length, corneal curvature, and anterior chamber depth.


METHODS
Using data from the fourth visit of the Beaver Dam Eye Study, we conducted familial correlation and heritability analysis of quantitative spherical equivalent, axial length, anterior chamber depth, and corneal curvature using data from 715 individuals in 189 pedigrees.


RESULTS
Overall, every trait was highly heritable. Heritability estimates were 0.58 (SE 0.13) for spherical equivalent after adjustment for age, education, and nuclear sclerosis; 0.95 (SE 0.11) for corneal curvature after adjustment for height; 0.67 (SE 0.14) for axial length after adjustment for height and education; and 0.78 (SE 0.14) for anterior chamber depth after adjustment for age, education, height, and nuclear sclerosis.


CONCLUSIONS
Refraction and the underlying traits of axial length, corneal curvature, and anterior chamber depth are highly heritable. Genetic analysis of these traits may provide greater insight into the development of refractive errors.
Sidney Kimmel Comprehensive Cancer Center, School of Medicine, Johns Hopkins University, Baltimore, MD 21231, USA. aklein1@jhmi.edu
Alison P
AP
Klein
Bhoom
B
Suktitipat
Priya
P
Duggal
Kristine E
KE
Lee
Ronald
R
Klein
Joan E
JE
Bailey-Wilson
Barbara E K
BE
Klein
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000867:Anterior Chamber / Q000473:pathology*; D001699:Biometry; D003315:Cornea / Q000473:pathology*; D005123:Eye / Q000473:pathology*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D019655:Quantitative Trait, Heritable; D012029:Refraction, Ocular / Q000235:genetics; D012030:Refractive Errors / Q000235:genetics*; D012931:Social Environment; D014922:Wisconsin