To screen for, detect, and monitor treatment for congenital adrenal hyperplasia (CAH); sometimes to help rule out other conditions
17-Hydroxyprogesterone
17-Hydroxyprogesterone
Também conhecido como
17-OHP
17-OH progesterone
Progesterone - 17-OH
Nome formal
17-Hydroxyprogesterone
Este artigo foi revisto pela última vez em
Este artigo foi modificado pela última vez em 10 de Julho de 2017.
At a Glance
Why Get Tested?
When To Get Tested?
As part of a routine newborn screen, when an infant has ambiguous genitalia, when a young female has hirsutism or other symptoms of virilization, when a male child has premature sexual development, and periodically to monitor CAH treatment
Sample Required?
A blood sample drawn from a vein in your arm or blood from a heelstick for an infant
Test Preparation Needed?
None
Accordion Title
Common Questions
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How is it used?The 17-hydroxyprogesterone (17-OHP) test is routinely ordered as part of newborn screening in the United States to detect congenital adrenal hyperplasia (CAH), a group of inherited disorders caused by specific gene mutations and associated with cortisol-related enzyme deficiencies. About 90% of CAH cases are caused by a mutation in the CYP21A2 gene that leads to a 21-hydroxylase deficiency and to accumulation of 17-OHP in the blood.
Up to 75% of newborns affected by 21- hydroxylase deficiency CAH will also produce less aldosterone, a hormone that regulates the retention of salt. The loss of too much fluid and salt in the urine can lead to a life-threatening adrenal crisis also called "salt-wasting" crises.
The 17-OHP test may be used to screen for CAH before symptoms appear or confirm a CAH diagnosis in persons with symptoms. The newborn screen is so sensitive that there may be a significant number of false positive test results. Positive 17-OHP screening tests may be repeated, or other tests performed, such as androstenedione and testosterone. If a 17-OHP test is abnormal, then an ACTH stimulation test may be also be ordered as a follow-up test. Molecular genetic testing may be performed to detect CYP21A2 gene mutations that can cause the condition. A karyotype test may be ordered as a follow-up test to detect chromosome disorders and to help determine a baby's sex. Electrolytes may be ordered to measure the person's sodium and potassium levels.
Measurement of 17-OHP in the blood may also be used to aid in the diagnosis of CAH in older children and adults who may have a milder, "late-onset" form.
If someone is diagnosed with 21-hydroxylase deficiency, treatment will involve suppressing ACTH production and replacement of the deficient cortisol with glucocorticoid treatment. A 17-OHP test may be used periodically to monitor the effectiveness of this treatment.
A 17-OHP test may also sometimes be used, along with other hormone tests, to help rule out CAH in people who have similar symptoms, such as hirsutism and irregular periods. This includes women with suspected polycystic ovarian syndrome (PCOS) and infertility, and rarely those with suspected adrenal or ovarian cancers.
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When is it ordered?The 17-OHP test is ordered routinely as part of a newborn screen and may be repeated if the screening test is elevated to confirm the initial results. A 17-OHP test may be ordered whenever an infant has signs and symptoms of adrenal insufficiency or experiences salt-wasting crises. Some signs and symptoms may include:
- Listlessness, lack of energy (lethargy)
- Not eating well
- Dehydration
- Low blood pressure
An infant with CAH may also have ambiguous genitalia, virilization, acne, or pubic hair.
This test may sometimes be ordered in older children or in adults when the milder form of CAH (late-onset) is suspected. The 17-OHP test may also be conducted when a girl or woman is experiencing symptoms such as:
- Hirsutism
- Lack of or irregular periods (menses)
- Virilization
- Infertility
In women, the symptoms are very similar to those of PCOS.
Boys or men may experience:
- Early (precocious) puberty
- Infertility
When a person has been diagnosed with 21-hydroxylase deficiency, then a 17-OHP test may be ordered periodically to monitor the effectiveness of treatment.
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What does the test result mean?If a newborn or infant has significantly elevated concentrations of 17-OHP, then it is likely that he or she has CAH. If a person has moderately increased levels, then they may have a less severe case of CAH, may have an 11-beta-hydroxylase deficiency (another enzyme defect that is associated with CAH), or may have a false positive test.
Normal 17-OHP results mean that it is likely that the person does not have CAH due to a 21-hydroxylase deficiency. Low or decreasing concentrations in a person with CAH indicate a response to treatment. High or increasing levels may indicate that changes in treatment are required.
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Is there anything else I should know?Premature infants often have elevated levels of 17-OHP. The newborn screen may need to be repeated at a later time.
Rarely, prenatal 17-OHP testing may be performed on amniotic fluid to detect and treat CAH in the fetus during pregnancy.
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Can I have CAH if no CYP21A2 gene mutations were detected during genetic testing?Yes. Testing detects the most common mutations but will not detect those that are rare. If a specific mutation has been identified in your family line, then you should be tested for that mutation.
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Can I have CAH with no symptoms of virilization?Yes. You may have a very mild deficiency or you may have CAH that is due to a different enzyme defect.
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Is 21-hydroxylase deficiency CAH curable?No, but it is treatable. Those with the condition will need to take glucocorticoids, and mineralcorticoids if their aldosterone is also low, throughout their life. In times of stress or illness, they may need extra medication to meet the needs of their body.