A study released recently has delved into the potential genetic cause for homosexuality. Though the study is not considered precisely conclusive, it brings scientists closer to finding a genetic connection to homosexuality in human males.

The study, titled "Genome-wide scan demonstrates significant linkage for male sexual orientation," was published on Psychological Medicine and compiled information gathered from 409 "independent pairs of homosexual brothers," which is "the largest study of its kind to date."

According to Discover magazine, the study involved studying X chromosome and chromosome 8, which has been discovered to relate to male sexual orientation. The study's lead scientist, Alan Sanders from NorthShore Research Institute in Illinois, collected blood and saliva samples from the pairs of brothers, which included twins.

The researchers then searched through the samples' genetic sequences for particular markers. Though all the men had different hair color, height, weight, intelligence, and other physical attributes, they are all gay.

Two genetic markers appeared the most frequently, the Xq28 region on the X chromosome and the 8q12 region on the 8 chromosome, which have led scientists to believe it is connected to male homosexuality.

However, there are skeptics. According to the Associated Press, Neil Risch, a genetics expert at the University of California, San Francisco, called the data "statistically too weak to demonstrate a genetic link." Others called it inconclusive.

The study, which was funded by the National Institutes of Health, is still seen as a step forward in the attempt to understand human sexuality.

For Dean Hamer, the new study is a vindication of his own research. According to Science, Hamer performed a gene study into homosexuality in 1993. The study validates, for Hamer, a project that caused much controversy at the time.

"When you first find something out of the entire genome, you're always wondering if it was just by chance," says Hamer, who claims that new research "clarifies the matter absolutely."

The study remains inconclusive, nonetheless. Sanders acquiesces that more data is required for a more precise finding. He will begin a DNA study that will involve 1000 gay men to find more data that could support or refute his findings.