Primary amenorrhea in four adolescents revealed 5α-reductase deficiency confirmed by molecular analysis

Poseidon and Caeneus: a case of pubertal gender inversion in Greek mythology

Disorders of sex development (DSDs) are very frequently encountered in ancient Greek mythology. One of the most striking types of DSD described in many myths is gender transformation wherein a female becomes a male or vice versa. Herein, we present via the marvelous myth of Poseidon and Caeneus a case of pubertal gender inversion. A medical interpretation of the myth whereby we attempt to form a diagnosis of this case of DSD is also presented.

The Genotype-Phenotype Correlation in Human 5α-Reductase Type 2 Deficiency: Classified and Analyzed from a SRD5A2 Structural Perspective

The phenotype of the 5α-reductase type 2 deficiency (5αRD2) by the SRD5A2 gene mutation varies, and although there have been many attempts, the genotype-phenotype correlation still has not yet been adequately evaluated. Recently, the crystal structure of the 5α-reductase type 2 isozyme (SRD5A2) has been determined. Therefore, the present study retrospectively evaluated the genotype-phenotype correlation from a structural perspective in 19 Korean patients with 5αRD2. Additionally, variants were classified according to structural categories, and phenotypic severity was compared with previously published data. The p.R227Q variant, which belongs to the NADPH-binding residue mutation category, exhibited a more masculine phenotype (higher external masculinization score) than other variants. Furthermore, compound heterozygous mutations with p.R227Q mitigated phenotypic severity. Similarly, other mutations in this category showed mild to moderate phenotypes. Conversely, the variants categorized as structure-destabilizing and small to bulky residue mutations showed moderate to severe phenotypes, and those categorized as catalytic site and helix-breaking mutations exhibited severe phenotypes. Therefore, the SRD5A2 structural approach suggested that a genotype-phenotype correlation does exist in 5αRD2. Furthermore, the categorization of SRD5A2 gene variants according to the SRD5A2 structure facilitates the prediction of the severity of 5αRD2 and the management and genetic counseling of patients affected by it.

Comprehensive molecular analysis identifies eight novel variants in XY females with disorders of sex development

Disorders of sex development (DSD) are a group of clinical conditions with variable presentation and genetic background. Females with or without development of secondary sexual characters and presenting with primary amenorrhea (PA) and a 46,XY karyotype are one of the classified groups in DSD. In this study, we aimed to determine the genetic mutations in 25 females with PA and a 46,XY karyotype to show correlations with their phenotypes. Routine Sanger sequencing with candidate genes like SRY, AR, SRD5A2, and SF1, which are mainly responsible for 46,XY DSD in adolescent females, was performed. In a cohort of 25 patients of PA with 46,XY DSD, where routine Sanger sequencing failed to detect the mutations, next-generation sequencing of a targeted gene panel with 81 genes was used for the molecular diagnosis. The targeted sequencing identified a total of 21 mutations including 8 novel variants in 20 out of 25 patients with DSD. The most frequently identified mutations in our series were in AR (36%), followed by SRD5A2 (20%), SF1 (12%), DHX37 (4%), HSD17B3 (4%), and DMRT2 (4%). We could not find any mutation in the DSD-related genes in five (20%) patients due to complex molecular mechanisms in 46,XY DSD, highlighting the possibility of new DSD genes which are yet to be discovered in these disorders. In conclusion, genetic testing, including cytogenetics and molecular genetics, is important for the diagnosis and management of 46,XY DSD cases.

Genotype-phenotype correlation, gonadal malignancy risk, gender preference, and testosterone/dihydrotestosterone ratio in steroid 5-alpha-reductase type 2 deficiency: a multicenter study from Turkey

BACKGROUND

Studies regarding genetic and clinical characteristics, gender preference, and gonadal malignancy rates for steroid 5-alpha-reductase type 2 deficiency (5α-RD2) are limited and they were conducted on small number of patients.

OBJECTIVE

To present genotype-phenotype correlation, gonadal malignancy risk, gender preference, and diagnostic sensitivity of serum testosterone/dihydrotestosterone (T/DHT) ratio in patients with 5α-RD2.

MATERIALS AND METHODS

Patients with variations in the SRD5A2 gene were included in the study. Demographic characteristics, phenotype, gender assignment, hormonal tests, molecular genetic data, and presence of gonadal malignancy were evaluated.

RESULTS

A total of 85 patients were included in the study. Abnormality of the external genitalia was the most dominant phenotype (92.9%). Gender assignment was male in 58.8% and female in 29.4% of the patients, while it was uncertain for 11.8%. Fourteen patients underwent bilateral gonadectomy, and no gonadal malignancy was detected. The most frequent pathogenic variants were p.Ala65Pro (30.6%), p.Leu55Gln (16.5%), and p.Gly196Ser (15.3%). The p.Ala65Pro and p.Leu55Gln showed more undervirilization than the p.Gly196Ser. The diagnostic sensitivity of stimulated T/DHT ratio was higher than baseline serum T/DHT ratio, even in pubertal patients. The cut-off values yielding the best sensitivity for stimulated T/DHT ratio were ≥ 8.5 for minipuberty, ≥ 10 for prepuberty, and ≥ 17 for puberty.

CONCLUSION

There is no significant genotype-phenotype correlation in 5α-RD2. Gonadal malignancy risk seems to be low. If genetic analysis is not available at the time of diagnosis, stimulated T/DHT ratio can be useful, especially if different cut-off values are utilized in accordance with the pubertal status.

5-α-Reductase type 2 deficiency: is there a genotype-phenotype correlation? A review

5-α-Reductase type 2 enzyme catalyzes the conversion of testosterone into dihydrotestosterone, a potent androgen responsible for male sexual development during the fetal period and later during puberty. Its deficiency causes an autosomal recessive disorder of sex development characterized by a wide range of under-virilization of external genitalia in patients with a 46,XY karyotype. Mutations in the SRD5A2 gene cause 5-α-Reductase deficiency; although it is an infrequent disorder, it has been reported worldwide, with mutational heterogeneity. Furthermore, it has been proposed that there is no genotype-phenotype correlation, even in patients carrying the same mutation. The aim of this review was to perform an extensive search in various databases and to select those articles with a comprehensive genotype and phenotype description of the patients, classifying their phenotypes using the external masculinization score (EMS). Thus, it was possible to objectively compare the eventual genotype-phenotype correlation between them. The analysis showed that for most of the studied mutations no correlation can be established, although the specific location of the mutation in the protein has an effect on the severity of the phenotype. Nevertheless, even in patients carrying the same homozygous mutation, a variable phenotype was observed, suggesting that additional genetic factors might be influencing it. Due to the clinical variability of the disorder, an accurate diagnosis and adequate medical management might be difficult to carry out, as is highlighted in the review.

Molecular diagnosis of 5α-reductase deficiency in 4 elite young female athletes through hormonal screening for hyperandrogenism

CONTEXT

Although a rare occurrence, previously undiagnosed disorders of sex development (DSD) with hyperandrogenism are sometimes detected by hormonal screening during the international sports competitions. Identifying the cause of XY,DSD raises medical and ethical concerns, especially with regard to issues of the eligibility to compete.

OBJECTIVE

The aim of this study was to determine whether the detection of high plasma T in young elite female athletes during hormonal screening would reveal an unsuspected XY DSD.

SETTING

The study was performed in the Nice and Montpellier University Hospitals (France), which collaborate as reference centers for DSD in elite athletes on behalf of sports governing bodies.

PATIENTS

Four cases of elite young athletes with female phenotypes but high plasma T detected during hormonal screening were investigated for undiagnosed XY DSD.

MAIN OUTCOME MEASURES

Evaluation of clinical, biological, radiological (magnetic resonance imaging and dual-energy x-ray absorptiometry) and genetic characteristics was conducted.

RESULTS

The 4 athletes presented as tall, slim, muscular women with a male bone morphotype, no breast development, clitoromegaly, partial or complete labial fusion, and inguinal/intralabial testes. All reported primary amenorrhea. The hormonal analysis evidenced plasma T within the male range, the karyotype was 46, XY, and molecular analysis of the 5α-reductase type 2 (srd5A2) gene identified a homozygotic mutation in 2 cases, a heterozygotic compound in 1 case, and a deletion in 1 case.

CONCLUSION

5α-Reductase deficiency should be investigated in elite young female athletes with primary amenorrhea and high male T levels detected during antidoping programs to identify undiagnosed XY DSD.

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.

The new policy on hyperandrogenism in elite female athletes is not about "sex testing"

In April 2011, the International Olympic Committee (IOC) and the International Association of Athletics Federations (IAAF) updated their regulations regarding elite female athletes with hyperandrogenism: Women whose testosterone levels crossed into the male range could not compete with other women unless it was shown that they are resistant to the effects of testosterone. Although the new rule is a marked improvement over past attempts to ensure that men were not trying to compete as women in elite competition, several criticisms have been leveled against the new regulations. Here we offer our reactions to claims that the new regulation promotes a sex-verification test, claims that intersex athletes will automatically be disqualified from competition, and proposals to either divide athletes based on variables beyond sex or completely eliminate sex groupings. Although elite sports can never achieve a perfectly level playing field, there should be parameters to which athletes must conform for a given sport. Yet elite athletes themselves should play a decisive role in what is best for their sport.

Current concepts in disorders of sexual development

Disorders of sex development (DSD) with or without ambiguous genitalia require medical attention to reach a definite diagnosis. Advances in identification of molecular causes of abnormal sex, heightened awareness of ethical issues and this necessitated a re-evaluation of nomenclature. The term DSD was proposed for congenital conditions in which chromosomal, gonadal or anatomical sex is atypical. In general, factors influencing sex determination are transcriptional regulators, whereas factors important for sex differentiation are secreted hormones and their receptors. The current intense debate on the management of patients with intersexuality and related conditions focus on four major issues: 1) aetiological diagnosis, 2) assignment of gender, 3) indication for and timing of genital surgery, 4) the disclosure of medical information to the patient and his/her parents. The psychological and social implications of gender assignment require a multidisciplinary approach and a team which includes ageneticist, neonatologist, endocrinologist, gynaecologist, psychiatrist, surgeon and a social worker. Each patient should be evaluated individually by multidisciplinary approach.