During the early 1970s, Dr. Julianne Imperato, a Cornell endocrinologist, conducted an expedition to the Dominican Republic to investigate reports of an isolated village where children appearing to be girls turned into men at puberty. In the village, these children were known as 'guevedoces' (literally, penis at 12 years). Also known locally as machihembras ('first women, then man'), these pseudohermaphrodites were documented serially in the following photographs published originally in the American Journal of Medicne (Am. J. Med. 62: 170-191, 1977):
In an isolated village of the southwestern Dominican Republic, 2% of the live births were in the 1970's, guevedoces (actually male pseudohermaphrodites). These children appeared to be girls at birth, but at puberty these 'girls' sprout muscles, testes, and a penis. For the rest of their lives they are men in nearly all respects (see photograph 6 below). Their underlying pathology was found to be a deficiency of the enzyme, 5-alpha Reductase.