title: A prospective study of the prevalence of nonclassical congenital adrenal hyperplasia among women presenting with hyperandrogenic symptoms and signs.
abstract: BACKGROUND
  The diagnosis of the polycystic ovary syndrome requires the exclusion of nonclassical congenital adrenal hyperplasia (NCAH).
  
  
  OBJECTIVE
  Our objective was to evaluate the actual prevalences of 21-hydroxylase and 11beta-hydroxylase deficiencies among women presenting with hyperandrogenic complaints.
  
  
  METHODS
  This study was performed at an academic hospital.
  
  
  METHODS
  A total of 270 consecutive unselected women presenting with hyperandrogenic symptoms were prospectively recruited.
  
  
  METHODS
  Basal and ACTH-stimulated 11-deoxycortisol and 17-hydroxyprogesterone concentrations were measured.
  
  
  METHODS
  The prevalences of 21-hydroxylase and 11beta-hydroxylase deficiencies were calculated, and the diagnostic performance of basal serum 17-hydroxyprogesterone levels for the screening of NCAH was evaluated by receiver operating characteristic curve analysis.
  
  
  RESULTS
  Six of the 270 patients had 21-hydroxylase-deficient NCAH that was confirmed by CYP21 genotyping, whereas no patient was diagnosed with 11beta-hydroxylase deficiency, for an overall NCAH prevalence of 2.2% (95% confidence limits 0.5-3.9%). According to receiver operating characteristic analysis, a single basal serum 17-hydroxyprogesterone determination has a 0.97 (95% confidence interval: 0.934-1.008) chance of detecting NCAH in hyperandrogenic women. In our experience, the most appropriate cutoff value for the detection of NCAH is a 17-hydroxyprogesterone above 1.7 ng/ml, showing a 100% sensitivity and a 88.6% specificity. Five of the six 21-hydroxylase-deficient NCAH patients carried a severe CYP21 allele requiring genetic counseling and highlighting the importance of excluding this disorder among hyperandrogenic patients.
  
  
  CONCLUSIONS
  The prevalence of NCAH among hyperandrogenic patients from Spain is 2.2%. Basal serum 17-hydroxyprogesterone measurements have an excellent diagnostic performance, yet the cutoff value should be established in each laboratory to avoid false-negative results.
authors.affiliation: Department of Endocrinology, Hospital Universitario Ramón y Cajal & Universidad de Alcalá, Carretera de Colmenar Viejo Km 9,1 E-28034 Madrid, Spain. hescobarm.hrc@salud.madrid.org
authors.forename: Héctor F
authors.initials: HF
authors.lastname: Escobar-Morreale
authors.forename: Raul
authors.initials: R
authors.lastname: Sanchón
authors.forename: José L
authors.initials: JL
authors.lastname: San Millán
mesh_terms: D019326:17-alpha-Hydroxyprogesterone / Q000097:blood; D000293:Adolescent; D000312:Adrenal Hyperplasia, Congenital / Q000097:blood / Q000175:diagnosis / Q000201:enzymology / Q000453:epidemiology*; D000328:Adult; D003350:Cortodoxone / Q000097:blood; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D017588:Hyperandrogenism / Q000097:blood / Q000175:diagnosis / Q000201:enzymology / Q000453:epidemiology*; D011085:Polycystic Ovary Syndrome / Q000097:blood / Q000175:diagnosis / Q000201:enzymology / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013030:Spain / Q000453:epidemiology; D013252:Steroid 11-beta-Hydroxylase / Q000378:metabolism; D013255:Steroid 21-Hydroxylase / Q000378:metabolism
chemical_list: D019326:17-alpha-Hydroxyprogesterone; D013255:Steroid 21-Hydroxylase; D013252:Steroid 11-beta-Hydroxylase; D003350:Cortodoxone