Figure 2.

Diagnosis of 21OHD. Reference standards for hormonal diagnosis were derived from Refs. (170, 171, 173, 174). These diagnostic thresholds appear similar for LC-MS/MS assays from limited data (175). 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.