The following syndromes of XY intersexuality are reviewed: 5alpha-reductase-2 deficiency, 17beta-hydroxysteroid dehydrogenase-3 deficiency, and complete and partial androgen insensitivity with attention focused on issues of gender identity. Each syndrome, with its unique presentation, provides an opportunity to explore the relative effects of nature (androgens) versus nurture (sex of rearing) in gender identity development. The phenomenon of gender role reversal in these conditions is described and theories on the determinants of gender identity formation are proposed. Issues of importance to psychiatrists in treating patients who have these conditions also are discussed.
