Validation of steroid ratios for random urine by mass spectrometry to detect 5α-reductase deficiency in Vietnamese children

Clin Chem Lab Med. 2022 May 24;60(8):1225-1233. doi: 10.1515/cclm-2022-0272. Print 2022 Jul 26.


Objectives: The 5α-reductase-type-2 deficiency (5ARD2) is a rare autosomal recessive 46,XY disorder of sex development caused by the mutated 5α-reductase type 2 (SRD5A2) gene. In this disease, defective conversion of testosterone to dihydrotestosterone leads to variable presentations of male ambiguous genitalia during fetal development. We aimed to examine characteristics of patients presenting with 5ARD2 over a 4 year period.

Methods: Random urine samples of control and patients with suspected 5ARD2 were collected and urine steroidomic metabolites were measured by Gas chromatography-mass spectrometry (GC-MS) in the period from 2017 to 2021 at National Children's Hospital, Hanoi Vietnam. 5α- to 5β-reduced steroid metabolite ratio, 5a-tetrahydrocortisol to tetrahydrocortisol (5α-THF/THF), was reviewed by receive operator characteristics (ROC) curve analysis. Molecular testing was offered to 25 patients who were diagnosed with 5ARD2 by GC-MS urinary steroid analysis.

Results: Urine steroidomic profiling was conducted for 104 male controls and 25 patients between the ages of 6 months and 13 years old. Twelve of the twenty-five 5ARD2 patients agreed to undertake genetic analysis, and two mutations of the SRD5A2 gene were detected in each patient, confirming the diagnosis. All patients showed a characteristically low ratio of 5α-THF/THF. There was no overlap of 5α-THF/THF ratio values between control and 5ARD2 groups. The ROC of 5α-THF/THF ratio at 0.19 showed 100% sensitivity and 100% specificity for boys between 6 months and 13 years of age.

Conclusions: Analysis of the urine steroid metabolome by GC-MS can be used to assist in the diagnosis of 5ARD2. We recommend consideration of random urine steroid analysis as a first-line test in the diagnosis of 5ARD2.

Keywords: 5α-reductase type 2 deficiency (5ARD2); disorders of sex development (DSDs); gas chromatography-mass spectrometry (GC-MS); urine steroid metabolome.

MeSH terms

  • 3-Oxo-5-alpha-Steroid 4-Dehydrogenase / deficiency
  • 3-Oxo-5-alpha-Steroid 4-Dehydrogenase / genetics
  • Asian People
  • Child
  • Disorder of Sex Development, 46,XY
  • Gas Chromatography-Mass Spectrometry
  • Humans
  • Hypospadias
  • Infant
  • Male
  • Membrane Proteins
  • Oxidoreductases*
  • Steroid Metabolism, Inborn Errors
  • Steroids* / urine
  • Tetrahydrocortisol / urine
  • Vietnam


  • Membrane Proteins
  • Steroids
  • Tetrahydrocortisol
  • Oxidoreductases
  • 3-Oxo-5-alpha-Steroid 4-Dehydrogenase
  • SRD5A2 protein, human

Supplementary concepts

  • Pseudovaginal Perineoscrotal Hypospadias