7
Figure 2. Diagnosis of 21OHD
Morning 17OHP
(Follicular Phase)
<200 ng/dL
(<6 nmol/L)
200–1,000 ng/dL
(6-30 nmol/L)
>1,000 ng/dL
(>30 nmol/L)
Cosyntropin
Stimulation Test
<1,000 ng/dL
(<30 nmol/L)
21OHD Excluded 21OHD
Reference standards for hormonal diagnosis were derived from Armengaud J-B et al.
J Clin Endocrinol Metab. 2009;94(8):2835–2840; Bidet Met al. J Clin Endocrinol Metab.
2009;94(5):1570–1578; Torok D et al. Exp Clin Endocrinol Diabetes. 2003;111(1):27–32;
Speiser PW et al. Clin Endocrinol (Oxf ). 1998;49(4):411–417; Wedell Aet al. J Clin Endocrinol
Metab. 1994;78(5):1145–1152. ese diagnostic thresholds appear similar for LC-MS/MS assays
from limited data (Wilson RCet al. J Clin Endocrinol Metab. 1995;80(8):2322–2329). Note that
randomly measured 17OHP levels can be normal in NCCAH; hence, 17OHP levels should be
screened in the early morning (before 8 AM). For menstruating females, steroid measurements
should be obtained in the follicular phase and may differ depending on the assay employed.
Individuals with classic CAH, including both salt-wasting and simple virilizing forms of 21OHD,
typically have unstimulated 17OHP values of several thousand. Note that it is sometimes difficult
to distinguish clinically between non–salt-wasting classic and nonclassic forms of CAH.