Number of genotyped individuals with their own and their offspring's phenotype (0-10000000):

Number of genotyped individuals with their own phenotype only (0-10000000):

Number of genotyped individuals with their offspring's phenotype only (0-10000000):

Number of genotyped mother-offspring pairs with offspring phenotype (0-10000000):

Number of genotyped mother-offspring pairs with both maternal and offspring phenotype (0-10000000):

Alpha level (0-1):

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

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

Maternal and Offspring effect is in opposite direction

Residual correlation between maternal and offspring phenotype(-1-1):

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

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

Power to detect either maternal or offspring genetic effect (2 df test):

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.
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 correlation between maternal and offspring phenotype refers to the residual correlation
between the phenotypes after the effect of the locus has been removed. This is likely to be close
to the phenotypic correlation between maternal and offspring phenotypes as the majority of loci will have a small effect.

NB. Maternal and offspring genetic effects can only be estimated uniquely when there are genotyped individuals who report their own phenotype and genotyped individuals who report their offspring's phenotype. These individuals do not need to be overlapping.

If you use the Maternal and Offspring Effects Power Calculator in your research please cite: Moen G, Hemani G, Warrington NM, Evans DM (accepted). Calculating power to detect maternal and offspring genetic effects in genetic association studies. Behav Genet.

R code for the Maternal and Offspring Genetic Effects Power Calculator can be found here.


If you encounter any error messages please contact the developers at g.h.o.moen@studmed.uio.no or d.evans1@uq.edu.au