title: Pitfalls in hormonal diagnosis of 17-beta hydroxysteroid dehydrogenase III deficiency.
abstract: Steroid 17β-hydroxysteroid dehydrogenase III (17β-HSD3) deficiency is a rare autosomal recessive disorder that usually presents in patients with a 46,XY karyotype with ambiguous genitalia at birth. The 17β-HSD3 enzyme, which is encoded by the HSD17B3 gene, converts gonadal delta-4 androstenedione (Δ4) to testosterone (T). Such 17β-HSD3 enzyme deficiency is expected to lead to an increased ratio of D4 to T when the patient undergoes a human chorionic gonadotropin stimulation (hCG) test. Two patients with 46,XY disorders of sexual differentiation were studied. Serum D4 and T levels were measured by HPLC tandem mass spectrometry. As one of the patients was born to consanguineous parents, we performed single nucleotide polymorphism (SNP) microarray to analyze regions of homozygosity (ROH). The HSD17B3 gene was sequenced using the Sanger method. Contrary to expectations, both patients demonstrated decreased D4/T ratio after hCG stimulation. Initial sequencing results for the androgen receptor or 5α-reductase were negative for mutations. ROH analysis identified HSD17B3 as a candidate gene that might cause the disease. Sanger sequencing of the HSD17B3 gene confirmed 17β-HSD3 deficiency in both patients. Serum D4/T ratios are not reliable parameters for the diagnosis of 17β-HSD3 deficiency. Molecular genetic analysis provides accurate diagnosis.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Khattab
authors.forename: Tony
authors.initials: T
authors.lastname: Yuen
authors.forename: Mabel
authors.initials: M
authors.lastname: Yau
authors.forename: Sorahia
authors.initials: S
authors.lastname: Domenice
authors.forename: Elaine Maria
authors.initials: EM
authors.lastname: Frade Costa
authors.forename: Kazmi
authors.initials: K
authors.lastname: Diya
authors.forename: Dwaipayan
authors.initials: D
authors.lastname: Muhuri
authors.forename: Christian Enrique
authors.initials: CE
authors.lastname: Pina
authors.forename: Mirian Yumie
authors.initials: MY
authors.lastname: Nishi
authors.forename: Amy C
authors.initials: AC
authors.lastname: Yang
authors.forename: Berenice Biharinho
authors.initials: BB
authors.lastname: de Mendonça
authors.forename: Maria I
authors.initials: MI
authors.lastname: New
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000737:chemistry / Q000172:deficiency* / Q000235:genetics; D000595:Amino Acid Sequence; D002648:Child; D002851:Chromatography, High Pressure Liquid; D058490:Disorder of Sex Development, 46,XY / Q000175:diagnosis*; D005260:Female; D006177:Gynecomastia / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010375:Pedigree; D020641:Polymorphism, Single Nucleotide; D017386:Sequence Homology, Amino Acid; D043202:Steroid Metabolism, Inborn Errors / Q000175:diagnosis*; D053719:Tandem Mass Spectrometry
chemical_list: D015067:17-Hydroxysteroid Dehydrogenases; C044256:3 (or 17)-beta-hydroxysteroid dehydrogenase