Güevedoce

The first scientific investigations of güevedoces occurred in the 1970s, when Julianne Imperato-McGinley, an endocrinologist from Cornell University, traveled to the village of Las Salinas in the Dominican Republic to investigate reports of apparently female children becoming male children at the onset of puberty.^[10] The cause was determined to be 5α-Reductase deficiency, and the results were published in the journal Science in 1974. The frequency of the deficiency was found to be unusually high in Las Salinas, with occurrence ratio of 1 güevedoce to every 90 unaffected males.^[11]

The transformation of güevedoces into an adult male at puberty, which is reported to be celebrated in Dominican culture, is the result of a genotypic male (with XY chromosomes) born with a deficiency in the enzyme 5α-reductase. 5α-Reductase is responsible for the reduction of testosterone to dihydrotestosterone. Dihydrotestosterone (DHT) is the hormone responsible for the majority of embryonic development of primary male sexual characteristics such as genital size. However, the oxidized form of the hormone, testosterone, promotes secondary sex characteristics. Thus, an XY child without functioning 5α-reductase cannot convert testosterone into the form that develops primary sex characteristics and will appear as if they have female genitalia. At puberty, when large amounts of testosterone are produced, secondary sex characteristics (e.g., deepening voice, hair pattern changes, muscle anabolism, etc.) develop, and their penis that was previously undermasculinized at birth begins to masculinize.

In adulthood, güevedoces most commonly self-identify as men, but are not necessarily completely treated as such by society.^[7]

Anne Fausto-Sterling states that güevedoces (as well as people in Papua New Guinea with 5α-reductase deficiency) "are recognised as a third gender" by their cultures, while the cultures "nevertheless recognize only two gender roles".^[7]

• Gender system
• 5α-Reductase deficiency