17-KSR Deficiency

17-KSR deficiency or 17-beta hydroxysteroid dehydrogenase 3 deficiency is an intersex variation that effects 1 in 147,000 newborn CTM or AMAB individuals (however those with this variation are also sometimes often incorrectly assigned female at birth as well.)

Most with this variation have a vagina, ambiguous genitals, or a micropenis instead of an average penis (despite their wolffian chromosomes). Those who do have an average penis usually have an oddly placed urethra. Because of this, they often also have hypogonadism and aromatase excess syndrome. All those with this variation have testicles. Depending on their type of genitalia, testes may be undescended (cryptorchidism), in the inguinal canal, or within labia.

Hypothyroidism occasionally occurs for those with this variation as well.

Upon puberty, those with this variation usually gain muscle mass, have a deepening voice, facial and body hair, and possibly breasts as well. They are unable to produce fertile sperm, making them infertile.

Causes
This variation occurs when the HSD17B3 gene does not properly provide instructions to an enzyme that is active in testicle production. Because of this, one does not produce testosterone at the same level as wolffians, and thus has more femininized traits outwardly.

History
This variation was originally described in 1971 by Saez and his colleagues.

17-KSR deficiency in Israel
In a specific area within Israel, incest and inbreeding is highly common, which causes the genetic development of many individuals to turn out in an unlikely manner. Because of this, 1 in every 100-150 individuals in this area were born with 17-KSR, which is a drastically high amount compared to the average rarity of the variation.

This does not mean that incestual relations is the reason for this variation, but rather means that it can intensify the likelihood of it in development.