Question

As part of an association study, you are asked to calculate the odds ratio of the X allele being associated with the brown eye trait in the Stony Brook student population. There are only two alleles at the relevant locus (X and Z). Out of 400 students sampled, 300 have brown eyes. Of all the students sampled, 150 have the X allele. 100 of the 150 students with the X allele also have brown eyes. Calculate the odds ratio of the X allele (risk allele) leading to brown eyes (phenotype of interest, a.k.a. “case”) versus the X allele not leading to brown eyes. Explicitly identify the number of exposed cases, exposed non-cases, unexposed cases, and unexposed non-cases. Then calculated the odds ratio, showing your work.

Answer 1