17β-hydroxysteroid dehydrogenase deficiency

17β-Hydroxysteroid Dehydrogenase Deficiency is a rare genetic disorder that affects the normal sexual development of an individual. It is caused by mutations in the HSD17B3 gene, which is responsible for the production of an enzyme called 17β-hydroxysteroid dehydrogenase 3. This enzyme plays a crucial role in the final step of testosterone production in males.

Causes

The primary cause of 17β-Hydroxysteroid Dehydrogenase Deficiency is mutations in the HSD17B3 gene. This gene provides instructions for making an enzyme that is involved in the production of male sex hormones (androgens). Specifically, this enzyme converts a hormone called androstanedione into testosterone. Mutations in the HSD17B3 gene reduce or eliminate the activity of this enzyme, preventing the body from producing enough testosterone for male sexual development.

Symptoms

The symptoms of 17β-Hydroxysteroid Dehydrogenase Deficiency can vary greatly among affected individuals. In males, the condition typically results in ambiguous genitalia, where the external sex organs do not look clearly male or clearly female. In some cases, affected individuals may appear to be female at birth and may be raised as girls. However, at puberty, they may develop typically male secondary sexual characteristics, such as increased muscle mass, deepening of the voice, and growth of facial hair.

Diagnosis

Diagnosis of 17β-Hydroxysteroid Dehydrogenase Deficiency typically involves a combination of physical examination, medical history, and laboratory tests. Genetic testing can confirm a diagnosis by identifying mutations in the HSD17B3 gene.

Treatment

Treatment for 17β-Hydroxysteroid Dehydrogenase Deficiency typically involves hormone replacement therapy to provide the body with the testosterone it is unable to produce. In some cases, surgery may be recommended to correct ambiguous genitalia.

See Also

• Androgen Insensitivity Syndrome
• 5-alpha reductase deficiency
• Congenital adrenal hyperplasia