Number of genotyped half sibling families (0-10000000):

Alpha level (0-1):

Maternal Genetic Effect - proportion of variance explained (0-1):

Paternal Genetic Effect - proportion of variance explained (0-1):

Offspring Genetic Effect - proportion of variance explained (0-1):

Maternal and Offspring Genetic Effect is in opposite direction

Paternal and Offspring Genetic Effect is in opposite direction

Residual covariance between half sibling pairs(-1-1):

Power to detect maternal genetic effect (1 df test):

NCP of test to detect maternal genetic effect:

Power to detect paternal genetic effect (1 df test):

NCP of test to detect paternal genetic effect:

Power to detect offspring genetic effect (1 df test):

NCP of test to detect offspring genetic effect:

Power to detect any genetic effect (3 df test):

NCP of test to detect any genetic effect:

The same utility can be used to estimate the power to detect association in paternal half siblings. Simply swap the results of the power to detect maternal and paternal genetic effects.

Alpha level is the type 1 error rate for the genetic association study.
Maternal genetic effect is the proportion of variance in the trait explained by maternal genetic effects at the locus.
Paternal genetic effect is the proportion of variance in the trait explained by paternal genetic effects at the locus.
Offspring genetic effect is the proportion of variance in the trait explained by offspring genetic effects at the locus.

If you have an effect size estimate and allele frequency for the genetic variant of interest, you can calculate the proportion of variance in the trait explained as (2*P*(1-P)*b^2)/VAR(trait), where P=allele frequency, b=effect size estimate.

Residual covariance between sibling pairs is approximately equal to the sib-pair correlation for loci of small effect.

If you use this utility in your research please cite: Hwang D et al. (in preparation) Detecting maternal and paternal genetic effects on offspring phenotypes using imputed parental genotypes

If you encounter any errors please contact the developers at d.evans1@uq.edu.au