Pubertal Suppression and Surgical Management of a Patient With 5-Alpha Reductase Deficiency.

Five-alpha reductase type 2 deficiency (5αRD2) is a rare cause of atypical genitalia in newborns. There are no definitive guidelines regarding management of children with this disorder. While many children are raised as female given the under-virilized appearance of their external genitalia at birth, these patients are historically counseled to undergo male puberty, resulting in a change in gender identity from female to male in more than half of post-pubertal patients. Here we report the first case of a patient with 5αRD2who identified as female from a very early age, strongly desired gender-affirming surgery, and elected to initiate puberty-blocking therapy prior to the onset of male puberty.

[Association between karyotype 47XYY and 5-alpha reductase deficiency revealed by micropenis: about a case and literature review]. / Association caryotype 47XYY et déficit en 5 alpha réductase révélée par un micropénis: à propos d'un cas et revue de la littérature.

Subjects with 47XYY often have normal amounts of gonadotropin-releasing hormone. In these subjects the association between 47XYY and 5-alpha reductase deficiency is rare. The common clinical manifestation of 5-alpha reductase deficiency is male pseudohermaphrodism, rarely it has been revealed by micropenis. Testosterone enanthate does not give good results in patients with 5-alpha reductase deficiency; dihydrotestosterone (DHT) has proven effectiveness in these cases. We report the case of a 17-year old patient, referred to our Hospital with micropenis. The patient didn't respond to two enanthate testosterone therapies. Assessment showed normal testosterone levels, amounts of gonadotropin-releasing hormone at the upper limit of normal, low DHT, elevated testosterone/DHT ratio>20, karyotype 47 XYY. This study highlights that 5-alpha reductase deficiency in these subjects raises the issue of simple coincidence or effective link.

Consequences of steroid-5α-reductase deficiency and inhibition in vertebrates.

In 1974, a lack of 5α-dihydrotestosterone (5α-DHT), the most potent androgen across species except for fish, was shown to be the origin of a type of pseudohermaphrodism in which boys have female-like external genitalia. This human intersex condition is linked to a mutation in the steroid-5α-reductase type 2 (SRD5α2) gene, which usually produces an important enzyme capable of reducing the Δ4-ene of steroid C-19 and C-21 into a 5α-stereoisomer. Seeing the potential of SRD5α2 as a target for androgen synthesis, pharmaceutical companies developed 5α-reductase inhibitors (5ARIs), such as finasteride (FIN) and dutasteride (DUT) to target SRD5α2 in benign prostatic hyperplasia and androgenic alopecia. In addition to human treatment, the development of 5ARIs also enabled further research of SRD5α functions. Therefore, this review details the morphological, physiological, and molecular effects of the lack of SRD5α activity induced by both SRD5α mutations and inhibitor exposures across species. More specifically, data highlights 1) the role of 5α-DHT in the development of male secondary sexual organs in vertebrates and sex determination in non-mammalian vertebrates, 2) the role of SRD5α1 in the synthesis of the neurosteroid allopregnanolone (ALLO) and 5α-androstane-3α,17ß-diol (3α-diol), which are involved in anxiety and sexual behavior, respectively, and 3) the role of SRD5α3 in N-glycosylation. This review also features the lesser known functions of SRD5αs in steroid degradation in the uterus during pregnancy and glucocorticoid clearance in the liver. Additionally, the review describes the regulation of SRD5αs by the receptors of androgens, progesterone, estrogen, and thyroid hormones, as well as their differential DNA methylation. Factors known to be involved in their differential methylation are age, inflammation, and mental stimulation. Overall, this review helps shed light on the various essential functions of SRD5αs across species.

[Preliminary investigation of gender assignment in 46,XY disorders of sex development with severe male undermasculinisation].

Objective: To explore the feasibility of gender assignment in 46,XY disorders of sex development (DSD) with severe undermasculinisation mainly based on molecular diagnosis. Methods: A retrospective study of 45 patients of 46, XY DSD with severe undermasculinisation were admitted between November 2015 and October 2018 at Children's Hospital, Zhejiang University School of Medicine. The initial social gender were all female, of whom the external genital manifestations were Prader 0 to 2; the degree of masculinity was scored using external masculinisation score (EMS); the position and development of the gonads were examined by ultrasound, cystoscopy and laparoscopy, also including assessing the development of the Wolffian tube and the Müllerian tube. The level and ratio of testosterone to dihydrotestosterone before and after hCG stimulation were evaluated for the function of Leydig cell and 5α-reductase-2. Gender role scales and sandbox games were used to assess gender role behavior. Genital sensitivity to androgen stimulation was assessed; A panel including 163 genes related to gender development were determined by second-generation sequencing in all 45 patients. Finally, a multidisciplinary team (MDT) makes a gender assignment after a comprehensive analysis mainly based on the molecular etiological diagnosis. Results: Thirty-nine out of 45 patients (87%) had an identifiable genetic etiology, and the remaining 6 (13%) were negative for genetic testing. Forty-five patients had EMS less than or equal to 3 points. Sexual psychological assessment was performed in 39 patients, with male dominance in 24 (62%) and female dominance in 15 (38%). The gender assignment was 23 cases (51%) for male and 19 cases (42%) for female, and 3 cases (7%) were not completely determined. Conclusions: Molecular diagnosis provides a strong basis for appropriate gender assignment of 46, XY DSD children with severe undermasculinisation. Based on molecular diagnosis, each DSD should be analyzed by professional MDT to analyze the clinical symptoms/signs, gonadal development, gonad tumor risk, external genital morphology, sexual psychological assessment, potential fertility opportunities, parental views, Social and cultural factors, etc. make appropriate gender assignment.

Identification of three novel SRD5A2 mutations in Chinese patients with 5α-reductase 2 deficiency.

In this study, we investigated the genetics, clinical features, and therapeutic approach of 14 patients with 5α-reductase deficiency in China. Genotyping analysis was performed by direct sequencing of PCR products of the steroid 5α-reductase type 2 gene (SRD5A2). The 5α-reductase activities of three novel mutations were investigated by mutagenesis and an in vitro transfection assay. Most patients presented with a microphallus, variable degrees of hypospadias, and cryptorchidism. Eight of 14 patients (57.1%) were initially reared as females and changed their social gender from female to male after puberty. Nine mutations were identified in the 14 patients. p.G203S, p.Q6X, and p.R227Q were the most prevalent mutations. Three mutations (p.K35N, p.H162P, and p.Y136X) have not been reported previously. The nonsense mutation p.Y136X abolished enzymatic activity, whereas p.K35N and p.H162P retained partial enzymatic activity. Topical administration of dihydrotestosterone during infancy or early childhood combined with hypospadia repair surgery had good therapeutic results. In conclusion, we expand the mutation profile of SRD5A2 in the Chinese population. A rational clinical approach to this disorder requires early and accurate diagnosis, especially genetic diagnosis.

Establishing reproductive potential and advances in fertility preservation techniques for XY individuals with differences in sex development.

BACKGROUND: Discordance between gonadal type and gender identity has often led to an assumption of infertility in patients with differences in sex development (DSD). However, there is now greater recognition of fertility being an important issue for this group of patients. Currently, gonadal tissue that may have fertility potential is not being stored for individuals with DSD and, where gonadectomy forms part of management, is often discarded. The area of fertility preservation has been predominantly driven by oncofertility which is a field dedicated to preserving the fertility of patients undergoing gonadotoxic cancer treatment. The use of fertility preservation techniques could be expanded to include individuals with DSD where functioning gonads are present. METHODS: This is a systematic literature review evaluating original research articles and relevant reviews between 1974 and 2018 addressing DSD and fertility, in vitro maturation of sperm, and histological/ultrastructural assessment of gonadal tissue in complete and partial androgen insensitivity syndrome, 17ß-hydroxysteroid dehydrogenase type 3 and 5α-reductase deficiency. CONCLUSION: Successful clinical outcomes of ovarian tissue cryopreservation are paving the way for similar research being conducted using testicular tissue and sperm. There have been promising results from both animal and human studies leading to cryopreservation of testicular tissue now being offered to boys prior to cancer treatment. Although data are limited, there is evidence to suggest the presence of reproductive potential in the gonads of some individuals with DSD. Larger, more detailed studies are required, but if these continue to be encouraging, individuals with DSD should be given the same information, opportunities and access to fertility preservation as other patient groups.

Paternity in 5α-Reductase-2 Deficiency: Report of Two Brothers with Spontaneous or Assisted Fertility and Literature Review.

Fertility remains a challenge for men with 5α-reductase-2 deficiency. Such a diagnosis was made in 2 adult brothers who are compound heterozygous for the 5α-reductase type 2 gene (SRD5A2; c.308G>C; c.689A>C). They were born with ambiguous genitalia and the male sex was assigned. Both brothers underwent reconstructive genital surgery during pediatric age and had spontaneous virilization at puberty. The older brother experienced natural conception, while the younger had a son by assisted reproductive technology. Other family members were demonstrated to be compound heterozygous or heterozygous for the same genetic variants. The older brother is the third man with 5α-reductase-2 deficiency and spontaneous paternity. The little series of men with 5α-reductase-2 deficiency and documented spontaneous or assisted paternity is reviewed. In conclusion, the possibility of fatherhood is a main indication for male sex assignment in patients with 5α-reductase-2 deficiency.

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.

Inborn Errors of Bile Acid Metabolism.

Inborn errors of bile acid metabolism are rare causes of neonatal cholestasis and liver disease in older children and adults. The diagnosis should be considered in the context of hyperbilirubinemia with normal serum bile acids and made by urinary liquid secondary ionization mass spectrometry or DNA testing. Cholic acid is an effective treatment of most single-enzyme defects and patients with Zellweger spectrum disorder with liver disease.

[Pathologic features on gonadal changes of sexual developmental disorders in children].

Objective: To investigate the pathologic features of gonadal tissues of disorders of sexual development (DSD) in children. Methods: Fifty-three cases of gonadal developmental disorders were collected from July 2015 to August 2017 at Guangzhou Women and Children's Medical Center. Clinical manifestations, karyotypes, sex hormone levels, ultrasound imaging, histology and immunophenotype of gonadal tissues were analyzed. Results: The age of patients ranged from 7 months to 17 years with an average of (50.7 ± 47.1) months. Social genders of the patients included 32 males and 21 females. Forty-eight patients had abnormal sex hormone levels. Clinical presentations included: toward female genitalia in 25 cases, male genitalia tendency in 17 cases and ambiguous external genitalia in 11 cases. Hypospadias was seen in 31 cases and short stature was seen in 8 cases. Chromosomal karyotyping of peripheral blood revealed 23 cases of sex chromosome disorders, 22 cases of 46 XY disorders, of which 3 cases were 5α-reductase deficiency and 8 cases of 46 XX disorders. Ultrasound examination showed cryptorchidism in 30 cases, including 16 cases of unilateral, 14 cases of bilateral and 1 case presenting a huge pelvic tumor. A total of 97 gonadal tissues from 53 cases of DSD were examined, including 9 cases of unilateral and 44 cases of bilateral gonads. Microscopically, 55 gonads (56.7%) showed dysplastic testes including 17 unilateral and 19 bilateral gonads. Fourteen were streak gonads (14.4%) including 8 unilateral and 3 bilateral gonadal tissues. Nine streak gonad with epithelial cord-like structures (9.3%) were found, of which 5 were unilateral and 2 were bilateral lesions. Seven gonads were ovotestis (7.2%), unilateral in 5 cases (the other side of the gonads of ovary in 4 cases, 1 case of dysplastic testes) and bilateral in 1 case. Seven gonads showed follicular-rich ovarian tissue (7.2%). One case showed bilateral dysplastic testes with gonadoblastoma and ectopic adrenal cortex. One case of streak gonad showed epithelial cord-like structures and undifferentiated glandular tissue embedded in malignant mixed germ cell tumors (mixed gonadoblastoma, dysgerminoma, mature teratoma and yolk sac tumor). One case had testicular microlithiasis. Uterus and fallopian tube structures were found in 11 cases. Immunohistochemical stains were performed in 15 cases. D2-40, PLAP and CKIT were expressed in germ cells and Calretinin, WT1 and inhibin were positive in Setoli cells. SALL4 and OCT3/4 were positive in 3 cases. Inhibin highlighted interstitial Leydig cells in 2 cases. GPC3 was positive in yolk sac tumor component. Conclusions: Gonadal dysgenesis presents a broad spectrum of gonadal phenotypes with variable degrees of differentiation. The development of bilateral gonadal tissues has certain variability. Chromosomal karyotypes have no correlation with gonadal phenotypes. Accurate histopathologic diagnosis of gonadal dysgenesis plays an important role in the treatment and prognosis of the patient.

Clinical and molecular characterization of 5α-reductase type 2 deficiency due to mutations (p.Q6X, p.R246Q) in SRD5A2 gene.

Early diagnosis and optimal management for steroid 5α-reductase type 2 deficiency (5α-RD2) patients are major challenges for clinicians and mutation analysis for the 5α-reductase type 2 (SRD5A2) gene is the golden standard for the diagnosis of the disease. In silico analysis of this enzyme has not been reported due to the lack of appropriate model. Moreover, the histological and pathological changes of the gonads are largely unknown. In the present study, a 5α-RD2 patient born with abnormal external genitalia was studied and mutation analysis for SRD5A2 gene was conducted. Moreover, we constructed the homology modeling of 5α-reductase using SWISS-MODEL, followed by the molecular docking study. Furthermore, immunohistochemical staining of Ki67 for the testes tissue was conducted to investigate the potential pathological characteristics. The patient had male (46, XY) chromosomes but presented female characteristics, and the mutation analysis identified a heterozygotes mutation (p.Q6X, p.R246Q) in SRD5A2 gene. In silico analysis elucidated the potential effect of the mutation on enzyme activity. Immunohistochemical staining for the excised testes showed that 30%-50% of the germ cells were Ki67 positive, which indicated the early neoplastic potential. In conclusion, we analyzed the genotype-phenotype correlations of 5α-RD2 caused by a heterozygotes mutation (p.Q6X, p.R246Q). Importantly, we conducted the homology modeling and molecular docking for the first time, which provided a homology model for further investigations. Immunohistochemical results suggested gonadectomy or testis descent should be performed early for 5α-RD2 patient, as delayed treatment would have maintained the testes in a tumorigenic condition.

Comparison between two inhibin B ELISA assays in 46,XY testicular disorders of sex development (DSD) with normal testosterone secretion.

BACKGROUND: Inhibin B is a hormone produced by the Sertoli cells that can provide important information for the investigation of disorders of sex development (DSD) with 46,XY karyotype. The aim of this study is to compare two enzyme-linked immunosorbent assay (ELISA) assays for dosage of serum inhibin B in patients with 46,XY DSD with normal testosterone secretion. METHODS: Twenty-nine patients with 46,XY DSD and normal testosterone secretion (partial androgen insensitivity syndrome [PAIS] [n=8]; 5α-reductase deficiency [n=7] and idiopathic 46,XY DSD [n=14]) were included. Molecular analysis of the AR and SRD5A2 genes were performed in all patients and the NR5A1 gene analysis in the idiopathic group. Measurements of inhibin B were performed by two second-generation ELISA assays (Beckman-Coulter and AnshLabs). Assays were compared using the interclass correlation coefficient (ICC) and the Bland-Altman method. RESULTS: ICC was 0.915 [95% confidence interval (CI): 0.828-0.959], however, a discrepancy was observed between trials, which is more evident among higher values when analyzed by the Bland-Altman method. CONCLUSIONS: It is recommended to perform the inhibin B measurement always using the same ELISA kit when several evaluations are required for a specific patient.

Late Diagnosis of 5-α-Reductase Type 2 Deficiency in an Adolescent Girl with Primary Amenorrhoea.

Deficiency of the 5-α-reductase enzyme has been found to affect male sexual development. We report an 18-year-old patient who was referred to an endocrinology clinic in Jizan, Saudi Arabia, in April 2014 with primary amenorrhoea, virilisation and a lack of secondary sex characteristics. As female external genitalia were present at birth, she had been raised as a female. Magnetic resonance imaging revealed no uterine or ovarian tissue in the pelvis and the presence of a scrotal sac. She was diagnosed with 5-α-reductase type 2 deficiency, a 46,XY disorder of sexual development. Typically, affected males have pseudovaginal perineoscrotal hypospadias and ambiguous genitalia at birth. Individuals who have been raised as female manifest characteristics of virilisation at puberty, including deepening of the vocal tone, phallus enlargement, scrotal hyperpigmentation and increased muscle mass.

46,XY disorder of sex development (DSD) due to 17ß-hydroxysteroid dehydrogenase type 3 deficiency.

17ß-hydroxysteroid dehydrogenase 3 deficiency consists of a defect in the last phase of steroidogenesis, in which androstenedione is converted into testosterone and estrone into estradiol. External genitalia range from female-like to atypical genitalia and most affected males are raised as females. Virilization in subjects with 17ß-HSD3 deficiency occurs at the time of puberty and several of them change to male social sex. In male social sex patients, testes can be safely maintained, as long as they are positioned inside the scrotum The phenotype of 46,XY DSD due to 17ß-HSD3 deficiency is extremely variable and clinically indistinguishable from other causes of 46,XY DSD such as partial androgen insensitivity syndrome and 5α-reductase 2 deficiency. Laboratory diagnosis is based on a low testosterone/androstenedione ratio due to high serum levels of androstenedione and low levels of testosterone. The disorder is caused by a homozygous or compound heterozygous mutations in the HSD17B3 gene that encodes the 17ß-HSD3 isoenzyme leading to an impairment of the conversion of 17-keto into 17-hydroxysteroids. Molecular genetic testing confirms the diagnosis and provides the orientation for genetic counseling. Our proposal in this article is to review the previously reported cases of 17ß-HSD3 deficiency adding our own cases.

Etiological diagnosis of undervirilized male/XY disorder of sex development.

OBJECTIVE: To do clinical, hormonal and chromosomal analysis in undervirilized male / XY disorder of sex development and to make presumptive etiological diagnosis according to the new Disorder of Sex Development (DSD) classification system. STUDY DESIGN: Case series. PLACE AND DURATION OF STUDY: Endocrine Unit at National Institute of Child Health, Karachi, Pakistan, from January 2007 to December 2012. METHODOLOGY: Patients of suspected XY DSD / undervirilized male visiting endocrine clinic were enrolled in the study. Criteria suggested XY DSD include overt genital ambiguity, apparent female/male genitalia with inguinal/labial mass, apparent male genitalia with unilateral or bilateral non-palpable testes, micropenis and isolated hypospadias or with undescended testis. The older children who had delayed puberty were also evaluated with respect to DSD. As a part of evaluation of XY DSD, abdominopelvic ultrasound, karyotype, hormone measurement (testosterone, FSH, LH), FISH analysis with SRY probing, genitogram, laparoscopy, gonadal biopsy and HCG stimulation test were performed. Frequencies and percentages applied on categorical data whereas mean, median, standard deviation were calculated for continuous data. RESULTS: A total of 187 patients met the criteria of XY DSD. Age ranged from 1 month to 15 years, 55 (29.4%) presented in infancy, 104 (55.6%) between 1 and 10 years and 28 (15%) older than 10 years. Twenty five (13.4%) were raised as female and 162 as (86.6%) male. The main complaints were ambiguous genitalia, unilateral cryptorchidism, bilateral cryptorchidism, micropenis, delayed puberty, hypospadias, female like genitalia with gonads, inguinal mass. The karyotype was 46 XY in 183 (97.9%), 46 XX in 2 (1.1%), 47 XXY in 1 (0.5%), 45 X/46 XY in 1 (0.5%) patient. HCG stimulation test showed low testosterone response in 43 (23 %), high testosterone response in 62 (33.2%), partial testosterone response in 32 (17.1%) and normal testosterone response in 50 (26.7%). Genitogram was carried out in 86 (45.98%) patients. Presumptive etiological diagnosis of androgen sensitivity syndrome/ 5-alpha reductase deficiency, testicular biosynthetic defect/ leydig cell hypoplasia, partial gonadal dysgenesis, ovotesticular DSD, XX testicular DSD, mixed gonadal dysgenesis, testicular vanishing syndrome, klinefelter syndrome, hypogonadotropic hypogonadism, isolated hypospadias and isolated micropenis was made. CONCLUSION: Clinical, chromosomal and hormonal assessment may help in making the presumptive etiological diagnosis. Further molecular genetics analysis are needed in differentiating these abnormalities and to make a final diagnosis.

Testicular histological and immunohistochemical aspects in a post-pubertal patient with 5 alpha-reductase type 2 deficiency: case report and review of the literature in a perspective of evaluation of potential fertility of these patients.

BACKGROUND: Testicular morphology and immunohistochemical studies have never been reported in genetically documented adult patients with 5 alpha-reductase type 2 deficiency (5α-R2 deficiency). CASE PRESENTATION: We describe the testicular histopathology of a 17-year-old XY subject with 5α-R2 deficiency caused by the recurrent homozygous Gly115Asp loss of function mutation of the SRD5A2 gene.We also performed an immunohistochemical analysis in order to further study the relationship between seminiferous tubules structure, Sertoli cell differentiation and androgenic signaling impairment in this case. We thus evaluated the testicular expression of the anti-Müllerian hormone (AMH), androgen receptor (AR) and 3ß-hydroxysteroid dehydrogenase (3ßHSD). Histological analysis revealed a heterogeneous aspect with a majority (92%) of seminiferous tubules (ST) presenting a mature aspect but containing only Sertoli cells and devoid of germ cells and spermatogenesis. Focal areas of immature ST (8%) were also found. Testicular AR and 3ßHSD expression were detected in adult male control, 5α-R2 deficiency and CAIS subjects. However, AMH expression was heterogeneous (detectable only in few AR negative prepubertal ST, but otherwise repressed) in the 5α-R2 deficiency, conversely to normal adult testis in which AMH was uniformly repressed and to an adult CAIS testis in which AMH was uniformly and strongly expressed. CONCLUSION: Intratesticular testosterone can repress AMH by itself, independently of its metabolism into dihydrotestosterone. We also compare our results to the few post pubertal cases of 5α-R2 deficiency with available histological testicular description, reported in the literature. We will discuss these histological findings, in the more general context of evaluating the fertility potential of these patients if they were raised as males and were azoospermic.

Female mice with deletion of Type One 5α-reductase have reduced reproductive responding during proestrus and after hormone-priming.

The capacity to form progesterone (P4)'s 5α-reduced metabolite, 5α-pregnan-3α-ol-20-one (3α,5α-THP; a.k.a. allopregnanolone), in the brain may be related to facilitation of lordosis among estrogen-primed (E2) mice. We investigated this idea further by comparing effects of endogenous and exogenous progestogens in mice that are deficient in the Type One 5α-reductase enzyme (5α-reductase knockout mice; 5α-RKO), and their wildtype counterparts for sexual behavior. Comparisons were made following administration of progestogens that are expected to increase 3α,5α-THP or not. Sexual receptivity of 5α-RKO mice and their wildtype counterparts was examined when mice were naturally-cycling (Experiment 1); ovariectomized (OVX), E2-primed (10 µg, subcutaneous; SC) and administered P4 (0, 125, 250, or 500 µg SC; Experiment 2); and OVX, E2-primed and administered P4, medroxyprogesterone acetate (MPA, 4 mg/kg, SC, which does not convert to 3α,5α-THP) or 3α,5α-THP (4 mg/kg, SC; Experiment 3). The percentage of mounts that elicited lordosis (lordosis quotient) or aggression/rejection behavior (aggression quotient), as well as the quality of lordosis (lordosis rating), was scored. Wildtype, but not 5α-RKO, mice in behavioral estrus demonstrated significantly greater lordosis quotients and lordosis ratings, but similar aggression quotients, compared to their diestrous counterparts. Among OVX and E2-primed mice, P4 facilitated lordosis of wildtype, but not 5α-RKO, mice. MPA neither facilitated lordosis of wildtype, nor 5α-RKO mice. 3α,5α-THP administered to wildtype or 5α-RKO mice increased lordosis quotients and lordosis ratings and decreased aggression quotients. 3α,5α-THP levels in the midbrain, one brain region important for sexual behavior, were increased during behavioral estrus, with P4 administered to WT, but not 5α-RKO mice, and 3α,5α-THP administered to WT and 5α-RKO mice. MPA did not increase 3α,5α-THP. Thus, deletion of Type One 5α-reductase among female mice may attenuate reproductive responding during the estrous cycle and after hormone-priming.

The effect of 5α-reductase-2 deficiency on human fertility.

A most interesting and intriguing male disorder of sexual differentiation is due to 5α-reductase-2 isoenzyme deficiency. These male infants are born with ambiguous external genitalia due to a deficiency in their ability to catalyze the conversion of T to dihydrotestosterone. Dihydrotestosterone is a potent androgen responsible for differentiation of the urogenital sinus and genital tubercle into the external genitalia, urethra, and prostate. Affected males are born with a clitoral-like phallus, bifid scrotum, hypospadias, blind shallow vaginal pouch from incomplete closure of the urogenital sinus, and a rudimentary prostate. At puberty, the surge in mainly T production prompts virilization, causing most boys to choose gender reassignment to male. Fertility is a challenge for affected men for several reasons. Uncorrected cryptorchidism is associated with low sperm production, and there is evidence of defective transformation of spermatogonia into spermatocytes. The underdeveloped prostate and consequent low semen volumes affect sperm transport. In addition, semen may not liquefy due to a lack of prostate-specific antigen. In the present review, we discuss the 5α-reductase-2 deficiency syndrome and its impact on human fertility.

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 5ß-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.