In the case of a case-control study, I can adjust the odds ratio for age, sex, BMI, clinicopathological data, etc., in determining the odds ratio for genotype data with logistic regression/multinomial logistic regression in SPSS. However, in the case of allele data, as an individual can carry two same (wild/variant) or two different alleles (heterozygote), how can I adjust the odds ratio with covariates (age, sex, BMI, clinicopathological data, etc.)?