Causes of transsexuality Docter and others, but opposed by Charles Allen Moser, Larry Nuttbrock, Julia Serano, and the World Professional Association for Transgender Health.<section end="factors" /> A 2008 study compared 112 male-to-female transsexuals (both androphilic and gynephilic), mostly already undergoing hormone treatment, with 258 cisgender male controls. Male-to-female transsexuals were more likely than cisgender males to have a longer version of a receptor gene (longer repetitions of the gene) for the sex hormone androgen or testosterone, which reduced its effectiveness at binding testosterone. The androgen receptor (NR3C4) is activated by the binding of testosterone or dihydrotestosterone, where it plays a critical role in
Thyroid hormone receptor Thyroid hormone receptor The thyroid hormone receptor (TR) is a type of nuclear receptor that is activated by binding thyroid hormone. Among the most important functions of thyroid hormone receptors are regulation of metabolism and heart rate. In addition, they play critical roles in the development of organisms. Thyroid hormone receptors regulate gene expression by binding to hormone response elements (HREs) in DNA either as monomers, heterodimers with retinoid X receptor (RXR; which in turn is activated by binding to 9-"cis"-retinoic acid) or as homodimers. However TR/RXR heterodimers are the most transcriptionally active form of TR. In the absence of