The hormones estrogen and androgen play critical roles in the development of sexual organs. 17ß-hydroxysteroid dehydrogenase isozyme (17ß-HSD) acts as a catalyst between the biologically inactive and active types of hormones. Any deviation from this normal process results into various abnormal conditions.

It is estimated in the Netherlands that 1 case in every 147,000 births show symptoms of 17ß-hydroxysteroid dehydrogenase deficiency which makes this deficiency very rare.

Steroid hormones have biological activities that are being regulated by some body enzymes. They are often regulated at the pre-receptor phase by such enzymes as 17 beta-hydroxysteroid dehydrogenases. These enzymes do not only regulate steroid concentrations but also bile and fatty acids in the body. The 17 beta-hydroxysteroid dehydrogenase enzyme is prevalent in all life forms (whether they are invertebrates, vertebrates or microorganisms). Malfunctions occur when this enzyme becomes deficient or imbalance in any way.

The most common types of illnesses that result from 17ß-hydroxysteroid dehydrogenase deficiency are cancers in various forms (ovarian, breast or prostate cancers); obesity of the upper body (prevalent among women); diabetes mellitus (the case that is not dependent on insulin); ambiguous sexual organs (females that appear to have ‘penis-like’ clitoris or grow up as males but are discovered later on to develop breasts or have menstrual periods). Pseudohermaphroditism in males is also known as 17-beta-hydroxysteroid dehydrogenase deficiency-3. It is one of the rarest cases of sexual development disorder. It is a condition that is autosomal recessive and is also a cause of disorders in sexual development in both the male and female species. Biochemically speaking, 17-beta-hydroxysteroid dehydrogenase deficiency-3 is characterized by lowered testosterone levels and an increase in the levels of androstenedione. This is a result of the failure in conversion to testosterone from androstenedione.

The recorded mutations of this syndrome are now up to 16 in number. The numbers are subdivided into 12 mutations that are missense, 3 mutations on splice junction, and a single tiny deletion which becomes an untimely stop codon.

Studies have been done to prove that pseudohermaphroditism is a result of the deficiency. It has been observed that subjects develop symptoms at puberty (either virilization or gynaecomastia). It also showed that the level of plasma androstenedione was about 4-5 times more than the normal level. The level of plasma testosterone, however, was very low when compared to the normal level.

17betahydroxysteroiddehydrogenasedeficiency