from Clinical/Therapeutic Issues
The study, "A genomewide scan of male sexual orientation," is published in the journal Human Genetics.
According to the lead author of the study, Dr. Brian Mustanski (University of Illinois, Chicago), "Our study helps to establish that genes play an important role in determining whether a man is gay or heterosexual. It expands upon previous research with twins, which has consistently found evidence for genetic influences on sexual orientation. The next steps will be to see if these findings hold up in a new sample and then identify the particular genes within these newly discovered chromosomal regions."
The genome scan involved 146 families that had two or more gay brothers. The researchers say that there is a statistically significant linkage to sexual orientation in a region on chromosome 7 called 7q36 and the second largest link was on chromosome 8 called 8p12. They also claim to have found a sexual orientation link in the region known as Xq28.
Two NARTH Scientific Advisory Committee members have analyzed this study and have found severe flaws in it.
According to Dr. Gerald Schoenewolf, the study's most noted researcher, Dr. Dean Hamer, is gay and has a pre-existing bias. The report, says Schoenewolf, "is written in super-scientific language in order to cover up the fact that it's totally biased. There is no balance in the article--no attempt to weigh various evidences or to speculate whether it could be interpreted environmentally. There is not even a mention of the environment. This is apparently a group of very intelligent homosexuals and pro-gay researchers looking for evidence of homosexual heredity."
Dr. A. Dean Byrd came to the same general conclusion after analyzing this study. He notes:
This is a "noble" effort that came up with nothing. Although the authors claim that the technology does not exist to do what they are trying to do, most scientists would be skeptical that they would be "successful" even with the technology. No significant loci were found that would identify male sexual orientation. The researchers' attempt to manipulate the data to come up with something meaningful was not realized. They find nothing and yet they insist that they might find something. Good science begins with a strong hypothesis not with a "fishing expedition" which is interpreted as something other than for what it is. Complex behaviors such as those involved with sexual orientation are likely polygenic and multifactoral--at the very most predispositions whose emergence and maintenance is strongly influenced by cultural and environmental factors.Dr. Sander Breiner also analyzed this study. He notes:
The initial casual perusal of the title and abstract would lead one to believe that this study has proven some genetic determinants for homosexuality. However, careful reading of the protocols and results denies that impression. There are constant qualifications and indications of limited proof throughout the paper. In addition, they do not describe the age of the children that were evaluated. Further, there is a statement that is completely invalid; "family and twin studies have provided evidence for a genetic component to male sexual orientation." At the end of the same paragraph there is a statement that indicates there is no hereditary component: "The results from family and twin studies demonstrate that sexual orientation is a complex (i.e. does not show simple Mendalian inheritance) and multifactorial phenotype."
Further qualifications, for example are: "an independent group produced inconclusive results regarding lineage to Xq 28."; a fourth study from another independent group found no support for linkage,"; "candidate gene studies have been conducted, both producing no results:"; "at most, only a fraction of the overall heritability of male sexual orientation was deduced from twin studies."
The author takes a hypothesis and treats it as having some validity without proof: for example, "hypothesized relationship between prenatal hormone and sexual orientation -- plays an important role in sexual development." If you will note my recent paper on Adolescent Homosexuality that describes the neurological development and functioning on the neurohormonal axis, indicates a distortion that the author leans towards.
The author use the term for what they expect as the "mlod"; then he goes on to suggest that the difference between what they expected what they got "denotes the possibility of etiologic heterogeneity for the proposed Xq28 locus." Shortly thereafter he qualifies the study further by stating "we were unable to calculate empirically derived significance levels for this project because none of the simulation programs that currently exist allow for the use of sex specific maps with ASP data." He then begs off about his results about the gene code being verified "because of financial limitations."
He then acknowledges that the study sample is too small to draw any conclusions. The author then makes an interesting statement; "our results may not extrapolate to individuals who do not meet our exclusion criteria." The author also eliminates female sexual orientation since it may have a different basis genetically than male sexual orientation.
It is obvious from the above that this is another poor study in an increasingly vast collection of poor studies that are quoted by each other's poor study to enhance the "scientific validity" of what they hypothesize.