I tracked down the paper. I'm always wary of ground-breaking research that is presented at conference ahead of publication. I have been unable to locate a published article using Google Scholar.
This is the first author: www.augusta.edu/faculty/directory/view.php?id=JTHEISEN
Website: www.abstractsonline.com/pp8/#!/4592/presentation/578
Not my area, so I have no understanding of this research or its findings.
Paper O-019 - Understanding the Genetic Basis of Transgender Identity
Authors
John G. Theisen, MD1, Mary S. Filchak1, Viji Sundaram, MD2, Lynn P. Chorich, MS1, Megan E. Sullivan, BS1, Michael J. Friez, PhD3, Hyung-Goo Kim, PhD1, Lawrence C. Layman, MD1.
1The Medical College of Georgia at Augusta University, Augusta, GA, USA, 2University of California, San Francisco, San Francisco, CA, USA, 3Greenwood Genetic Center, Greenwood, SC, USA.
Abstract
Introduction: Transgender identity occurs in 0.3% of the population and presents unique healthcare related challenges. One significant barrier to the management of transgender identity is the lack of understanding of its biological basis. Though previous research suggests a genetic etiology, no realistic candidate genes have yet been described. We hypothesized that transgender identity has a biological basis and that transgender individuals will have mutations in genes that regulate steroid metabolism in the brain during development.
Methods: Whole exome sequencing was performed on genomic DNA of 14 female-to-male and 16 male-to-female patients who met DSM-V criteria for transgender identity. Variants that appeared in the ExAC database at a frequency of less than 0.01% and that were predicted to be functional, particularly in pathways of sex steroid metabolism, were chosen as candidates. Those variants that were confirmed by Sanger sequencing were considered for further study.
Results: Whole exome sequencing, with a coverage of 98.36% and average read depth of 75, was performed in 30 transgender patients, demonstrating 120,000 genetic variants. After filtering, 30 variants in 20 genes were selected for further analysis. These included 9 likely pathogenic variants of genes involved in neurological development and/or sex steroid metabolism, as well as 11 missense variants predicted to be deleterious. Sanger sequencing was performed on 21/30 variants (9 are still ongoing). Of those, 18/21 variants were confirmed. The majority of confirmed variants (16/18) were heterozygous, while two were homozygous.
Conclusion: We identified genetic variants in 20 genes that may play a role in transgender identity. The most promising of these include variants of genes involved in neurologic development and sex hormone pathways. We will continue to enroll transgender patients and their families. We will also perform functional analysis to assess the extent that selected variants affect their respective pathways.