17-hydroxyprogesterone (17 OHPG)
17-OHPG is produced by the adrenal glands and also by the placenta, testes, and ovaries. OHPG is converted into cortisol by several enzymes, and is then released in the blood in varying amounts. It regulates metabolism and immune system. The deficiency of these enzymes affects the conversion of OHPG into cortisol – and as a result, there is a build-up of OHPG in the blood. When this happens, a condition called congenital adrenal hyperplasia (CAH) results wherein the production of male sex hormones (androgens) increases. Therefore, the 17-OH progesterone test is recommended to test this condition.
Why is the test ordered?
The test may be routinely ordered as a new-born screening test to detect CAH. It is a useful screening test for detecting CAH in older children and adults without symptoms and for confirming CAH diagnosis in individuals with symptoms. The test may also be frequently ordered to check the effectiveness of any treatment being undertaken for CAH.
When is the test ordered?
The test is ordered as a new-born screening test. The test may be recommended in patients (infants, children and adults) who are suspected to be suffering from congenital adrenal hyperplasia. The test is recommended for an infant or young child with the following symptoms:
- Disinterest in eating
- Lack of energy
- Possessing ambiguous genitals.
The test may be ordered for a girl or a woman with these symptoms:
- Excessive hair growth
- Deep voice
- Irregular periods or lack of menses
- Male sexual characteristics.
In adults and young boys the symptoms include
- A deep voice
- Early onset of puberty
How is the sample collected?
A blood sample is collected from a vein in the arm.
How to prepare for the test?
No preparation is required for this test.