title: An easily missed diagnosis: 17-alpha-hydroxylase/17,20-lyase deficiency.
abstract: The CYP17A1 gene encodes the enzyme P450c17, which mediates both 17α-hydroxylase and 17,20-lyase activities and is essential for production of cortisol and sex steroids. Loss-of-function mutations of this gene cause 17α-hydroxylase/17,20-lyase deficiency, characterized by hypertension, hypokalemia and sexual infantilism. A 6-year-old phenotypically female patient presented with hypertension and hyperpigmentation. Her blood test results showed low cortisol and high adrenocorticotropic hormone (ACTH), progesterone, deoxycorticosterone and gonadotropin levels and were consistent with the diagnosis of 17α-hydroxylase/17,20-lyase deficiency. Her karyotype was 46XY. Genetic studies of the patient revealed a novel homozygous point mutation, c.1307G>A, within the coding sequence of the CYP17A1 gene. 17α-hydroxylase/17,20-lyase deficiency should be considered in the differential diagnosis of hypertension in children and adolescents, and physical examination of these patients should be done very carefully.
authors.affiliation: Division of Pediatric Endocrinology, Department of Pediatrics, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkey. bnaydin@istanbul.edu.tr.
authors.forename: Banu
authors.initials: B
authors.lastname: Küçükemre-Aydın
authors.forename: Özlem
authors.initials: Ö
authors.lastname: Öğrendil-Yanar
authors.forename: Ilmay
authors.initials: I
authors.lastname: Bilge
authors.forename: Firdevs
authors.initials: F
authors.lastname: Baş
authors.forename: Şükran
authors.initials: Ş
authors.lastname: Poyrazoğlu
authors.forename: Alev
authors.initials: A
authors.lastname: Yılmaz
authors.forename: Sevinç
authors.initials: S
authors.lastname: Emre
authors.forename: Rüveyde
authors.initials: R
authors.lastname: Bundak
authors.forename: Nurçin
authors.initials: N
authors.lastname: Saka
authors.forename: Feyza
authors.initials: F
authors.lastname: Darendeliler
mesh_terms: D000312:Adrenal Hyperplasia, Congenital / Q000175:diagnosis* / Q000201:enzymology / Q000235:genetics; D000324:Adrenocorticotropic Hormone / Q000097:blood; D002648:Child; D005260:Female; D006720:Homozygote; D006801:Humans; D007621:Karyotyping; D017354:Point Mutation; D013254:Steroid 17-alpha-Hydroxylase / Q000378:metabolism
chemical_list: D000324:Adrenocorticotropic Hormone; D013254:Steroid 17-alpha-Hydroxylase