Ptl differentiated C21OHD and PORD from TH17OHP and controls with 96.
All metabolites of 17,20-lyase products showed significant differences between C21OHD and PORD [DHEA metabolites, P < 0.
We established a 2-step biochemical differential diagnosis for C21OHD and PORD by urinary steroid profile.
Increased Ptl and Ptl/THEs in C21OHD and PORD must reflect the impaired activity of 21-hydroxylase.
Decreased 11HA in PORD must reflect the impaired activity of 17,20-lyase.
We have reported that the ratio of 17[alpha]-hydroxypregnenolone metabolites to DHEA metabolites discriminated 22 patients with PORD from healthy infants (13), whereas this ratio could not discriminate C21OHD and PORD completely in this cohort (data not shown).
Enzymatic residual activity in PORD has been reported to differ depending on genotype (17).
In conclusion, we demonstrated a 2-step biochemical differential diagnosis for C21OHD and PORD by urinary steroid metabolites such as Ptl, THEs, and 11HA.
6] Nonstandard abbreviations: C21OHD, classic 21-hydroxylase deficiency; 17OHP, 17[alpha]-hydroxyprogesterone; POR, cytochrome P450 oxidoreductase; PORD, POR deficiency; TH17OHP, transient hyper 17OHPnemia; Ptl, pregnanetriolone; 21DOF, 21-deoxycortisol; 11HA, 11[beta]-hydroxyandrosterone; PD, pregnanediol; GC-MS-SIM, GC-MS/selected ion monitoring; THE, tetrahydrocortisone; DHEA, dehydroepiandrosterone; AD4, androstenedione; 11OHAD4, 11[beta]-hydroxyandrostenedione.