Dihydrotestosterone, Free, Serum

Dihydrotestosterone, Free, Serum - This test assesses the serum levels of dihydrotestosterone (DHT) and can aid in diagnosing 5 alpha-reductase deficiency, an autosomal recessive disorder affecting male sexual development. Evaluating DHT levels is also utilized to assess treatments that influence androgen levels. DHT is the most powerful androgen and is crucial for the development of male external genitalia, prostate enlargement, and skin metabolism.

DHT mainly originates from testosterone through 5-alpha-reductase activity in peripheral tissues, but it can also be produced via a "backdoor pathway" without testosterone as a precursor. Individuals with 5-alpha-reductase deficiency experience reduced conversion of testosterone to DHT, so a high testosterone-to-DHT ratio may indicate this condition. A definitive diagnosis of 5-alpha-reductase deficiency requires DNA analysis of SRD5A2.

Most circulating DHT is bound to sex hormone-binding globulin (SHBG). Since SHBG levels can be affected by medications, diseases, and sex steroids, measuring free DHT provides a more accurate reflection of bioactive DHT levels than total serum DHT measurement. Although DHT has been circumstantially linked to prostate tumorigenesis, current evidence does not support a connection between high serum DHT levels and an increased risk of benign prostatic hyperplasia and prostate cancer.

Test Details Include:

Dihydrotestosterone and DHT, Free

Preferred Specimen(s):

1.5 mL serum collected in a red-top tube (no gel)

Minimum Volume:

1 mL

Methodology:

Equilibrium Dialysis • Chromatography/Mass Spectrometry