It is not linked to deficient hormone amounts or action, but rather to a failure of the fetal genital tubercle to form between 3 and 6 weeks after conception.
Although aphallia can occur in any body type, it is considered a substantially more troublesome problem with those who have testes present, and has in the past sometimes been considered justification for assigning and rearing a male infant as a girl, after the outdated 1950s theory that gender as a social construct was purely nurture and so an individual child could be raised early on and into one gender or the other.
The nurture theory has been largely abandoned and cases of trying to rear children this way have not proven to be successful transitions.
[4][5][6] Recent advances in surgical phalloplasty techniques have provided additional options for those still interested in pursuing surgery.
[11] However, due to the stigma of the condition and the issues of keeping accurate statistics and records among doctors, it is likely there are more cases than reported.