The prevalence of 5 alpha-reductase deficiency in children with ambiguous genitalia in the Dominican Republic

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

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.

Phenotype variation among siblings with 5-alpha reductase deficiency: A case series

Steroid 5α-reductase deficiency (5ARD) is a rare autosomal recessive disorder caused by mutation in the 5α-reductase type 2 gene (SRD5A2). 5ARD results in the impaired conversion of testosterone (T) to dihydrotestosterone (DHT) and is characterized by undervirilization in 46XY individuals. We report a case series of three siblings presenting with ambiguous genitalia and different phenotypes. They did not meet the widely accepted biochemical criteria for 5ARD. In view of strong clinical suspicion, genetic analysis was performed which revealed pathogenic mutation in SRD5A2. This report highlights the importance of definitive diagnosis with molecular methods as the treatment and prognosis differs greatly among the close differential diagnoses. Reliance on the biochemical criteria alone may lead to misdiagnosis.

The impact of culture on disclosure in differences of sex development

Differences of sex development (DSD) include a variety of complex congenital genitourinary abnormalities-whether sporadic or hereditary. The 2006 DSD Consensus Statement and 2016 Update Consensus Statement encourage better communication among providers, between providers and parents, as well as among providers, parents, and patients when developmentally appropriate.^1,2 However, a lack of clear communication about the diagnosis and its sequelae may occur at three levels: (1) disclosure from DSD patients' families to their physician, (2) disclosure from patients to their families/communities, and (3) disclosure from the physician to the DSD patient. Additionally, there is a paucity of research available on how culture can impact disclosure among individuals with DSDs. This article discusses disclosure among the various stakeholders and briefly explores the impact of cultural expectations and beliefs with regards to disclosure.

Controversies of Sex Re-assignment in Genetic Males with Congenital Inadequacy of the Penis

Sex assignment in 46XY genetic male children with congenital inadequacy of the penis (CIP) is controversial. Traditionally, children with penile length less than 2 cm at birth are considered unsuitable to be raised as males. They are typically re-assigned to female-sex and feminizing genitoplasty is usually done in infancy. However, the concept of cerebral androgen imprinting has caused paradigm shift in the philosophy of sex re-assignment. Masculinization of the brain, rather than length of the penis, is the modern criterion of sex re-assignment in CIP. This review summarizes the current understanding of the complex issue. In 46XY children with CIP, male-sex assignment appears appropriate in non-hormonal conditions such as idiopathic micropenis, aphallia and exstrophy. Female-sex re-assignment appears acceptable in complete androgen insensitivity (CAIS), while partial androgen insensitivity syndrome (PAIS) patients are highly dissatisfied with the assignment of either sex. Children with 5-alpha reductase deficiency are likely to have spontaneous penile lengthening at puberty. Hence, they are better raised as males. Although female assignment is common in pure gonadal dysgenesis, long-term results are not known to justify the decision.

Diagnosis of 5α-Reductase 2 Deficiency: Is Measurement of Dihydrotestosterone Essential?

BACKGROUND

5α-Reductase 2 deficiency (5ARD) is a known cause of 46,XY disorders of sex development (DSD). Traditionally, the diagnosis relies on dihydrotestosterone (DHT) measurement, but the results are often equivocal, potentially leading to misdiagnosis. We reviewed alternative approaches for diagnosis of 5ARD.

METHODS

We conducted a retrospective review of the results of urinary steroid profiling (USP) by GC-MS and mutational analysis of SRD5A2 [steroid-5-alpha-reductase, alpha polypeptide 2 (3-oxo-5 alpha-steroid delta 4-dehydrogenase alpha 2)] by PCR and direct DNA sequencing of all 46,XY DSD patients referred to our laboratory with biochemical and/or genetic findings compatible with 5ARD. We also performed a literature review on the laboratory findings of all 5ARD cases reported in the past 10 years.

RESULTS

Of 16 patients diagnosed with 5ARD between January 2003 and July 2012, 15 underwent USP, and all showed characteristically low 5α- to 5β-reduced steroid metabolite ratios. Four patients had DHT measured, but 2 did not reach the diagnostic cutoff. In all 12 patients who underwent genetic analysis, 2 mutations of the SRD5A2 gene were detected to confirm the diagnosis. Twenty-four publications involving 149 patients with 5ARD were published in the review period. Fewer than half of these patients had DHT tested. Nearly 95% of them had the diagnosis confirmed genetically.

CONCLUSIONS

5ARD can be confidently diagnosed by USP at 3 months postnatally and confirmed by mutational analysis of SRD5A2. Interpretation of DHT results may be problematic and is not essential in the diagnosis of 5ARD. We propose new diagnostic algorithms for 46,XY DSD.

Defects of steroidogenesis

In the biosynthesis of steroid hormones the neutral lipid cholesterol, a normal constituent of lipid bilayers is transformed via a series of hydroxylation, oxidation, and reduction steps into a vast array of biologically active compounds: mineralocorticoids, glucocorticoids, and sex hormones. Glucocorticoids regulate many aspects of metabolism and immune function, whereas mineralocorticoids help maintain blood volume and control renal excretion of electrolytes. Sex hormones are essential for sex differentiation in male and support reproduction. They include androgens, estrogens, and progestins. A block in the pathway of steroid biosynthesis leads to the lack of hormones downstream and accumulation of the upstream compounds that can activate other members of the steroid receptor family. This review deals with the clinical consequences of these blocks.

The coexistence of male pseudohermaphrodites with 17-ketosteroid reductase deficiency and 5 alpha-reductase deficiency within a Turkish kindred

Two distinct enzyme defects affecting androgen production and resulting in male pseudohermaphroditism were found in a Turkish kindred from a small isolated village in the Taurus mountains of southern Turkey. Pedigree analysis revealed the inter-relationships of 9 male pseudohermaphrodites. Six affected subjects had adequate steroid hormone analysis. Two adult male pseudohermaphrodites had 17-ketosteroid reductase deficiency with elevated concentrations of plasma androstenedione relative to testosterone, and elevated concentrations of urinary androsterone (A) and etiocholanolone (E) relative to tetrahydrocortisol (THF), 5 alpha-tetrahydrocortisol (5 alpha-THF) and tetrahydrocortisone (THE). Four affected males (three adults, one child) had 5 alpha-reductase deficiency (elevated ratios of plasma testosterone/dihydrotestosterone and urinary 5 beta/5 alpha C19 and C21 steroid metabolites). The homozygous state for both enzyme deficiencies was not demonstrable in the same affected subject, suggesting that the enzyme deficiencies are segregating separately within this kindred. Whether the mutant genes are segregating on allelic chromosomes or other autosomes cannot be determined from this study.