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The Guevedoces

Gender metamorphosis at work

Elizabeth Kelley

Fall 2005

guevedoces gender metamorphosis machihembra    It’s a girl! …right? Sometimes, the answer is not so clear. In an isolated village in the southwestern region of the Dominican Republic and in the eastern highlands of Papua New Guinea, amazing cases of natural gender transformation in human populations have been reported. Some males with female phenotypes at birth begin to develop physical male characteristics during puberty. This phenomenon poses many challenging questions about what defines gender and how societies shape their concepts of it.

    In the 1970s, Julianne Imperato, PhD, of Cornell University traveled to the Dominican Republic to investigate claims of young female-appearing children developing masculine features. The locals referred to the phenomena by two names: guevedoces, translated to mean “penis at age twelve,” and machihembras, meaning “first a woman, then a man.” In the following years, reports suggested that this was also common in the Sambian villages of Papua New Guinea, where the locals called these individuals turnims, meaning “expected to become men.”

    The guevedoces, machihembras, and turnims are born with an XY genotype and both sex chromosomes intact. During fetal development, the sex determining region of the Y chromosome (SRY) inhibits female internal sexual organ development and induces the development of internal male sexual organs. Both guevedoces and normal male fetuses possess functioning SRY.

    But what causes these males to appear female? They seem to lack functioning copies of the 5 α-reductase enzyme, which converts testosterone to the biologically active dihydrotestosterone (DHT). In the absence of DHT, the postnatal external genitalia appear to be an ambiguous clitoris and labia.

    In the past, guevedoces were automatically regarded as females and raised as such. As any normal male would, guevedoces have a sudden increase in testosterone levels during puberty, which may cause the clitoris to enlarge. This surge of testosterone, in turn, may be responsible for the initiation of normal male sexual development and often results in the growth of facial and body hair and the deepening of the voice. Subsequently, most guevedoces spend their adult years resembling sexually normal males, though subtle differences still exist. For example, most have decreased amounts of facial hair and smaller prostate glands relative to the average male.

    Research has shown this genetic disorder to be of autosomal recessive inheritance. Due to the decreased size of the gene pool in these communities as well as their isolation from other populations, this condition persists for generations.
During the 1970s, guevedoces births were reported to account for as many as two percent of all births in these small villages of the Dominican Republic. Since then, doctors in villages in both the Dominican Republic and Papua New Guinea have become experts in distinguishing normal female external genitalia from the ambiguous genitalia of guevedoces babies. Due to the prevalence of these births, both cultures believe in three sexual categories: the male, the female, and the pseudohermaphrodite.

    The differences in the way these two societies deal with this rare occurrence hint at the magnitude to which a society’s culture can affect an individual’s beliefs and opinions. The Sambians view these children as flawed males; the children are rejected and humiliated by their families and society. On the other hand, in the Dominican Republic, the birth of a psueodhermaphrodite is fully accepted and during puberty, the child’s physical transformation into a male is marked by joyous celebration. Gemma Nierman, PhD, of St. Mary’s College and summer lecturer at University of California, Berkeley, remarks, “the Dominican Republic communities that quietly accept their citizens with 5 α-reductase deficiency are a model to the world on how to deal with genetic differences...[they] are showing us how to help these folks have a full and rewarding life despite their genetic disorder.”

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