It is a rare condition, with only approximately 60 cases reported as of 1989, and 75 cases as of 2005. However, due to the stigma of intersex conditions and the issues of keeping accurate statistics and records among doctors, it is likely there are more cases than reported.
Aphallia is of unknown causes. 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. The urethra of an affected child opens on the perineum.
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 genetically male infant as a girl. Intersex people generally advocate harshly against coercive genital reassignment however, and encourage infants to be raised choosing their own gender identity.
Recent advances in surgical phalloplasty techniques have provided additional options for those still interested in pursuing surgery.
^De Castro R, Merlini E, Rigamonti W, Macedo A (2007). "Phalloplasty and urethroplasty in children with penile agenesis: preliminary report". J. Urol.177 (3): 1112–6; discussion 1117. doi:10.1016/j.juro.2006.10.095. PMID17296424.