A is for 5 Alpha Reductase Deficiency

Our A word for today is 5 Alpha Reductase Deficiency, one of the more common intersex conditions.  5 alpha reductase deficiency is a recessive mutation where a genetic male does not produce 5 alpha reductase.  5 alpha reductase is the enzyme that converts testosterone into dihydrotestosterone.  The lack of dihydrotestosterone can result in male, female, or ambiguous genitalia.  People with 5 alpha reductase deficiency have testicles and usually are born with female primary sex characteristics and a male gender identity.  At puberty most 5 alpha reductase deficiency will masculinize considerably.  With testicles it may be possible for them to father children, but they are at a higher risk for testicular cancer.  Interestingly, without dihydrotestosterone, they will not suffer male pattern baldness.  Because it is a recessive genetic trait, certain populations have higher rates of 5 alpha reductase deficiency.  In the Dominican Republic 5 alpha reductase deficiency is so common they have a local name for it, guevedoce (eggs at twelve, a reference to testicles descending in an often seemingly female child).