Gender Genetics Complex

At its meeting last month, the Board of Trustees voted to have APA support the legal recognition of same-sex civil marriage. This vote came after the Assembly had approved the same position at its May meeting. The position statement emphasizes a variety of psychological and social reasons for recognizing same-sex couples. I would like to add a biological imperative to the arguments.

Opposition to same-sex marriages rests on the assumption that gender is unambiguously divided into male and female. However, various studies have found that up to 2 percent of live births—as many as 80,000 annual births—vary from the standard definitions of chromosomal, genital, gonadal dimorphism. At the chromosomal level a multitude of genetic patterns is possible. For example, instead of XY, there are males with XXY, XXYY, XXXY, XXXXY, and XYY. Among females, there are some who have only one X chromosome, those who have three, and others who have a mosaic of one X mixed with XX. There are also autosomal (non-sex gene) mutations that can affect gender. The most common form is called “pseudo-hermaphroditism,” which includes congenital adrenal hyperplasia in females and testicular feminization syndrome due to androgen insensitivity in males.

Last, there are persons who have normal chromosomal and anatomical makeup, and yet their gender does not conform to standards. They include a range of persons who are clinically diagnosed as having gender identity disorder. These persons have a strong and persistent cross-gender identification.

Thus, our traditional dichotomous classification poses problems at the chromosomal, anatomical, and psychological levels.

In reality, there is neither an absolute “genetic” male or“ genetic” female, nor is there an absolute “male” or“ female” gender identity, just a spectrum of expressions. Because gender cannot be easily categorized, it renders laws about sex and marriage illusory. As physicians and psychiatrists, we have an obligation to clarify this issue for policymakers and the general public.