>>16627399We think that we can explain 35% of the observed population of male homosexuals with genetic pathways already described in the literature. I highly doubt that homosexuality is 100% heritable, we will probably see it reach about 50% being explained as more pathways are published.
The three most common genetic pathways for male homosexuality are:
1. Genes of the glutamate membrane transporter family
2. Genes of the melanoma associated antigen family (Xq28)
3. Gene of unknown function in linkage with the centromere of chromosome 8
The most recent GWAS study found a series of glutamate transport genes (at chromosomes 5p13, 5q31, 7q32, 8p22, and 10q23) that have SNPs with p-values of association equal to 0.00000001.
That means, assuming the hypothesis that there is NO association between these genes and homosexuality with gender nonconformity in children, the probability of observing a result as or more extreme than the one observed by the researchers is only 0.00000001. The standard significance value for these publications is only 0.01.
https://www.scholars.northwestern.edu/en/publications/genome-wide-linkage-and-association-study-of-childhood-gender-non 