How To Calculate The Effect Size Of Snps Vs Percent Body Fat?

Question

[Samuel David]

I need to justify my assumptions and need to calculate the effect size of SNPs (25 in total) vs Body fat percent which range between 1.2% body fat per allele change to 1.8% body fat per allele change. Need to find SNPs of interest have a Minor Allele Frequency that ranges from 20-40% for the sample size of 250, 300 and 500 subjects and power given to be 80% and 90% based on any alpha value.

Answer 1

[Larry_Parnell]

My colleague presented a formula to calculate this for variants in APOA5 in humans for triglyceride concentrations across ethnic groups in Singapore. His paper, which includes that formula, can be found here.

[Samuel David]

what is called effect size of SNPs? is it the regression coefficient?

[Samuel David]

thank you very much for your help.

[Larry_Parnell]

The effect size is the beta. From "Statistics at the Bench" by M Bremer and R W Doerge (CSH Press): Effect size is the difference between the control and treatment group that you are trying to detect.