17-OHP optimal range and reference range

The screening test for congenital adrenal hyperplasia, including the non-classical adult form that mimics PMOS (formerly polycystic ovary syndrome). Draw it in the morning, and in a menstruating woman in the follicular phase — a luteal sample reads several-fold higher for entirely normal reasons. A clearly raised morning follicular value warrants a stimulation test rather than a diagnosis. The upper edge of 2 ng/mL (200 ng/dL, 6 nmol/L) is the recognised screening threshold: MedlinePlus states that an adult level above it may be due to non-classical adrenal hyperplasia. Draw it early in the morning in the follicular phase; luteal-phase results run higher. The narrower optimal edge is a functional target. The upper edge of 2 ng/mL (200 ng/dL, 6 nmol/L) is the recognised screening threshold: MedlinePlus states that an adult level above it may be due to non-classical adrenal hyperplasia, and Mayo Clinic Laboratories gives a follicular-phase limit of 0.8 against 2.85 luteal. The narrower optimal edge is a functional target.

Menstrual cycle: Range is a follicular-phase reference. The luteal phase runs several-fold higher, which is normal rather than a finding.

Assay: Results differ meaningfully between platforms and methods. Compare against the interval printed by the issuing laboratory before acting on a borderline value.

The steroid immediately upstream of the 21-hydroxylase step, which accumulates when that enzyme is deficient.

The screening test for congenital adrenal hyperplasia, including the non-classical form that presents in adulthood as androgen excess and can look exactly like PMOS (formerly polycystic ovary syndrome). Draw it in the morning and, in a menstruating woman, in the follicular phase — it rises after ovulation and a luteal sample reads falsely high.