Development Of Male External Genitalia Research Articles

Elevated plasma miR-210 expression is associated with atypical genitalia in patients with 46,XY differences in sex development.

Differences of sex development (DSD) is a term used for conditions in which the chromosomal, gonadal or phenotypical sex is atypical. 46,XY DSD patients frequently present undervirilized external genitalia. The expression of different miRNAs in many organs of the male genital system has been reported, and these miRNAs have been associated with testicular function and its disorders, but no description has been related to DSD conditions. This study aimed to evaluate the plasma expression of miR-210 in 46,XY DSD patients who presented atypical genitalia at birth. Eighteen 46,XY DSD patients who presented atypical genitalia (undescended testis and/or hypospadias, bifid scrotum or micropenis) at birth and 36 male control individuals were selected. Plasma levels of miR-210 and reference miR-23a were measured using RT-qPCR and the data were analysed by the 2-ΔCt method. MiR-210 plasma levels were significantly higher in 46,XY DSD patients with atypical genitalia than in male control subjects (p=0.0024). A positive association between miR-210 levels and the presence of cryptorchidism and hypospadias (p=0.0146 and p=0.0223) was found in these patients. Significantly higher levels of miR-210 were observed in patients with 46,XY DSD and cryptorchidism than in control subjects (p=0.0118). These results are in agreement with previous literature reports, in which increased levels of miR-210 expression were observed in human testicular tissue from adult males with undescended testes in comparison with samples of descended testes. Our study showed a positive association between the presence of atypical genitalia and plasma levels of miR-210 expression in the group of patients with 46,XY DSD of unknown aetiology studied. These findings contribute to reveal a new perspective on the role of miRNAs in the development of male external genitalia and the broad spectrum of phenotypes presented by patients with 46,XY DSD.

The anti-androgenic fungicide triticonazole induces region-specific transcriptional changes in the developing rat perineum and phallus

Intrauterine exposure to endocrine disrupting chemicals can interfere with male reproductive development. This can lead to male reproductive disorders such as hypospadias, cryptorchidism and reduced fertility, as well as shorter anogenital distance (AGD) – a biomarker for incomplete androgen-dependent fetal masculinization. However, it remains challenging to predict adverse in vivo outcomes based on in vitro effect patterns for many chemicals. This is a challenge for modern toxicology, which aims to reduce animal testing for chemical safety assessments. To enable the transition towards higher reliance on alternative test methods, we need to better map underlying mechanisms leading to adverse effects. Herein, we have analyzed the transcriptome of the perineum and phallus of male fetal rats and defined the impacts of exposure to an anti-androgenic fungicide, triticonazole. Previously we have shown that developmental exposure to triticonazole can induce short male AGD, but without a marked effect on the transcriptome of the fetal testes. In contrast, we report here significant changes to the transcriptional landscape of the perineum and phallus, including regional differences between these adjacent tissues. This highlights the importance of analyzing the correct tissue when characterizing mechanisms of complex in vivo effect outcomes. Our results provide a rich resource for the spatiotemporal gene networks that are involved in the development of male external genitalia, and that can be disrupted upon exposure to chemicals that prevent normal masculinization of the perineum and phallus. Such data will be critical in the development of novel alternative test methods to determine the endocrine disrupting potential of existing and emerging chemicals.

Preliminary Reference Interval for 5-Alpha Reductase in Normal Male Children and Its Association with Hypospadias.

5-alpha reductase (5-AR) enzyme is responsible for conversion of testosterone to dihydrotestosterone (DHT) in humans, which subserves various functions. The aim of the study was to establish a normal reference interval (RI) for blood levels of the enzyme 5-AR. We conducted a prospective study on 150 boys, 75 of whom underwent circumcision for various benign conditions or for religious reasons (Group A/controls) and 75 suffering from hypospadias of variable severity (Group B/cases). The plasma levels of 5-AR were measured by enzyme-linked immunosorbent assay (ELISA) in all 150 boys and correlated with the severity of hypospadias. The 5-AR levels in Group A ranged from 14.6 to 17.3 ng/mL. The enzyme levels decreased in value with increasing severity of hypospadias in Group B (P-value <0.01 - statistically significant). The levels of the enzyme in this group ranged from 0.6 ng/mL (in the most severe variety of hypospadias) to 11.5 ng/mL (mild variety of hypospadias). There is no record of RI values of 5-AR in the literature. The RI of 5-AR needs to be determined by conducting more studies globally. Its levels falls considerably with clinical severity of hypospadias, reinforcing the importance of the enzyme in the development of male external genitalia.

A novel variant luteinizing hormone receptor in the first transmembrane helix of two homozygous Iranian patients: case report

BackgroundLeydig cell hypoplasia (LCH) is a rare autosomal recessive endocrine syndrome that affects the normal development of male external genitalia in 46, XY individuals and is one of the causes of disorder of sexual differentiation (DSD) in males. The responsible gene of LCH is LHCGR which is located on the chromosome 2 and its various mutations lead to different degrees of the disease ranging from micropenis to complete XY DSD.Case presentationIn this study, we have investigated the clinical presentation and molecular findings of two siblings with complete male LCH and XY DSD. This is the first detailed report of individuals with LCH from Iran. It aimed to study the molecular and clinical characteristics of two sisters with type 1 LCH. Whole exome sequencing was used for these patients to find the underlying genetic cause of the disease. Our Iranian DSD patients had external genitalia (normal labia major and minor, the external opening of the urethra beneath the clitoris) and bilateral testicular tissues in the inguinal region, which were removed by surgical exploration.ConclusionsGenetic sequencing showed the homozygous variants of the LHCGR gene in the patients, a novel duplication variant in exon 11, c.1091dupT -or pLeu365Profs*5. This mutation is described as likely pathogenic. We think that this case report can widen the genotypic spectrum of the LHCGR variants. Moreover, this study emphasizes the significant rule of Whole Exome Sequencing in differentiating various causes of disorder of sexual differentiation.

The evolving role of whole-exome sequencing in the management of disorders of sex development.

ObjectiveDisorders of sex development (DSD) are defined as congenital conditions in which the development of chromosomal, gonadal and anatomical sex is atypical. Despite wide laboratory and imaging investigations, the etiology of DSD is unknown in over 50% of patients.MethodsWe evaluated the etiology of DSD by whole-exome sequencing (WES) at a mean age of 10 years in nine patients for whom extensive evaluation, including hormonal, imaging and candidate gene approaches, had not identified an etiology.ResultsThe eight 46,XY patients presented with micropenis, cryptorchidism and hypospadias at birth and the 46,XX patient presented with labia majora fusion. In seven patients (78%), pathogenic variants were identified for RXFP2, HSD17B3, WT1, BMP4, POR, CHD7 and SIN3A. In two atients, no causative variants were found. Mutations in three genes were reported previously with different phenotypes: an 11-year-old boy with a novel de novo variant in BMP4; such variants are mainly associated with microphthalmia and in few cases with external genitalia anomalies in males, supporting the role of BMP4 in the development of male external genitalia; a 12-year-old boy with a known pathogenic variant in RXFP2, encoding insulin-like 3 hormone receptor, and previously reported in adult men with cryptorchidism; an 8-year-old boy with syndromic DSD had a de novo deletion in SIN3A.ConclusionsOur findings of molecular etiologies for DSD in 78% of our patients indicate a major role for WES in early DSD diagnosis and management – and highlights the importance of rapid molecular diagnosis in early infancy for sex of rearing decisions.

Estrogens and development of the mouse and human external genitalia

The Jost hypothesis states that androgens are necessary for normal development of the male external genitalia. In this review, we explore the complementary hypothesis that estrogens can elicit abnormal development of male external genitalia. Herein, we review available data in both humans and mice on the deleterious effects of estrogen on external genitalia development, especially during the “window of susceptibility” to exogenous estrogens.The male and female developing external genitalia in both the human and mouse express ESR1 and ESR2, along with the androgen receptor (AR). Human clinical data suggests that exogenous estrogens can adversely affect normal penile and urethral development, resulting in hypospadias. Experimental mouse data also strongly supports the idea that exogenous estrogens cause penile and urethral defects. Despite key differences, estrogen-induced hypospadias in the mouse displays certain morphogenetic homologies to human hypospadias, including disruption of urethral fusion and preputial abnormalities. Timing of estrogenic exposure, or the “window of susceptibility,” is an important consideration when examining malformations of the external genitalia in both humans and mice. In addition to a review of normal human and mouse external genital development, this article aims to review the present data on the role of estrogens in normal and abnormal development of the mouse and human internal and external genitalia. Based on the current literature for both species, we conclude that estrogen-dependent processes may play a role in abnormal genital development.

Chromosomal Mutation In Isolated Hypospadias Patients Using High-Resolution Melting Curve (HRM)

Chromosomal Mutation In Isolated Hypospadias Patients Using High-Resolution Melting Curve (HRM)

The genetic factors contributing to hypospadias and their clinical utility in its diagnosis.

Hypospadias is among the most common congenital malformations in male neonates. It results from abnormal penile and urethral development, but is a multifactorial disorder that is highly heterogeneous, with several genetic and environmental determinants. Monogenic and chromosomal abnormalities are present in approximately 30% of cases, although the genetic factors contributing to hypospadias remain unknown in 70% of cases. While defects in androgen synthesis can lead to this malformation, mutational analyses have shown several genes, such as sonic hedgehog, fibroblast growth factors, bone morphogenetic proteins, homeobox genes, and the Wnt family, are involved in the normal development of male external genitalia. Mutations in the genes of penile development (e.g., HOX, FGF, Shh) and testicular determination (e.g., WT1, SRY), luteinizing hormonereceptor, and androgen receptor have also been proposed to be implicated in hypospadias. Here we review the recent advances in this field and discuss the potential genes that could determine the risk of hypospadias.

Perineal lipoma mimicking an accessory penis with scrotum

A case of accessory penis with scrotum in a 4 months old boy is reported because of its rarity. The infant presented with a tumour mimicking an accessory penis with scrotum between the normal sited scrotum and anus. Both testes had descended into the scrotum. After complete evaluation, there was no other urological anomaly. The tumour was excised and the histo-pathological findings of the tumor indicated a perineal lipoma. An overview of normal development of male external genitalia has been provided and the deranged mechanism resulting in this anomaly has been reviewed with hypothesis regarding etiology of accessory scrotum.

46,XY disorder of sexual development resulting from a novel monoallelic mutation (p.Ser31Phe) in the steroid 5α-reductase type-2 (SRD5A2) gene.

Inactivating mutations of the 5α-steroid reductase type-2 (SRD5A2) gene result in a broad spectrum of masculinization defects, ranging from a male phenotype with hypospadias to a female phenotype with Wolffian structures. Molecular studies of the SRD5A2 revealed a new heterozygous gene variant within the coding region that results in phenotypic expression. A c.92C>T transition changing serine to phenylalanine at codon 31 of exon 1 (p.Ser31Phe) was identified in a patient with 46,XY disorder of sexual development who displayed glandular hypospadias with micropenis and bilateral cryptorchidism. The restoration of the p.Ser31Phe mutation by site-directed mutagenesis and transient expression assays using cultured HEK-293 cells showed that this novel substitution does not abolish but does deregulate the catalytic efficiency of the enzyme. Thus, the maximum velocity (Vmax) value was higher for the mutant enzyme (22.5 ± 6.9 nmol DHT mg protein−1 h−1) than for the wild-type enzyme (9.8 ± 2.0 nmol DHT mg protein−1 h−1). Increased in vitro activity of the p.Ser31Phe mutant suggested an activating effect. This case provides evidence that heterozygous missense mutations in SRD5A2 may induce the abnormal development of male external genitalia.

A case report of a novel homozygote mutation causing severe Leydig cell hypoplasia: insights in the coexistence of nonsense mutation and polymorphism in the same LHCGR gene locus

Introduction: Leydig cell hypoplasia is a rare autosomal recessive condition that interferes with normal development of male external genitalia in 46,XY individuals. It is mediated by mutations in the lutropin/choriogonadotropin receptor (LHCGR) gene, resulting in impairment of either hormone binding or signal transduction. Case report: We report a 32-year-old female patient who presented with primary amenorrhoea, female external genitalia and 46,XY karyotype. Breast and pubic hair development were of B2 and PH2 respectively. Magnetic resonance imaging revealed at both sides inguinal testicles (cryptorchidism) with microcalcification in the absence of uterus and ovaries. At first presentation, serum luteinizing hormone was about 3-fold above the normal limit, while testosterone was in the normal female adult range. Estradiol was low and the serum follicle-stimulating hormone was unremarkable. Dehydroepiandrosterone sulphate, 17-hydroxyprogesterone and sex hormone-binding globulin were normal. Anti-Mullerian hormone and inhibin B were elevated. Mutation or deletion of the sex-determining region Y-, androgen receptor- and steroid 5-alpha-reductase-gene could be excluded. Finally, sequencing of the lutropin-choriogonadotropic hormone receptor gene revealed a homozygote nonsense mutation in exon 10 (c.907C>T, p.Gln 303Trm). Interestingly, a second a second polymorphism was found (c.935A>G, p.Asn312Ser) downstream of the disruption of the gene sequence. We therefore concluded to the diagnosis of severe Leydig cell hypoplasia. A hormone replacement therapy with estradiol was inducted and the further operative removal of the inguinal testicles as well as the genetic analysis of the parents is planned. Conclusions: We report a phenotypically female patient with 46,XY disorder of sexual development with a novel homozygote nonsense mutation (p.Gln303Trm) accompanied by a second homozygote polymorphism (p.Asn312Ser) in the LHCGR gene. Our case expands the genotypic spectrum of LHCGR mutations and underlines the importance of thorough molecular analysis.

A novel severe N-terminal splice site KISS1R gene mutation causes hypogonadotropic hypogonadism but enables a normal development of neonatal external genitalia

Kisspeptin 1 receptor (KISS1R) gene mutations are rare but have recently become an important etiology of normosmic isolated hypogonadotropic hypogonadism (IHH). To characterize the genetic defect, the phenotype, and response to therapy of three IHH siblings with a novel severe KISS1R mutation. Three siblings (16- and 22-year-old sisters and their 20-year-old brother) born to consanguineous parents with normal neonatal external genitalia presented with no pubertal development, normosmia, and a low response to GNRH stimulation. Homozygosity mapping, KISS1R gene sequencing, and RNA expression were performed. The females' basal low estradiol level (50 pmol/l) failed to rise in response to human chorionic gonadotropin (hCG). The brother's low testosterone (1.87 nmol/l) responded to combined hCG and human menopausal gonadotropin (hCG) and HMG therapies, but the testes remained small (1-2 ml). Secondary sexual characteristics were attained by exogenous sex steroid replacement. SNP array studies revealed shared homozygosity for a chromosome 19 region encompassing KISS1R. Sequencing revealed a novel homozygous KISS1R mutation at the nt-1 canonical acceptor splice site of intron 1 in affected siblings. The mother (menarche at 14 years) was heterozygous. cDNA sequencing showed that the G>A mutation results in skipping of exon 2 and a premature stop codon at residue 151. The novel severe N-terminal KISS1R splice site (c.245-1G>A) mutation results in IHH. Heterozygous female carriers may manifest a subtle fertile phenotype. The subnormal gonadal response to hCG in patients may implicate a direct role of KISS1R in gonadal function. The normal neonatal virilization in a male homozygous to this severe mutation challenges the hypothesis that KISS1R is required for fetal development of male external genitalia.

Perineal Accessory Scrotum with Congenital Lipoma: A Rare Case Report

A case of accessory scrotum in a 1-year-old boy is reported because of its rarity. A boy presented with a tumor mass attached with scrotum-like skin on its tip in the right side of perineum between the scrotum and anus. Both testes had descended into the scrotum. There was no other urological anomaly. Histological findings of the tumor indicated perineal lipoma, and the scrotum-like portion accessory scrotum. An overview of sequences during the normal development of male external genitalia has been provided and the deranged mechanism resulting in this anomaly has been reviewed with hypothesis regarding etiology of accessory scrotum.

Growth and Development of Male External Genitalia: A Cross-Sectional Study of 6200 Males Aged 0 to 19Years

Growth and Development of Male External Genitalia: A Cross-Sectional Study of 6200 Males Aged 0 to 19Years

Polymorphisms of MAMLD1 gene in hypospadias

Purpose Mastermind-like domain containing 1 (MAMLD1) is a causative gene for the fetal development of male external genitalia. Almost 10% of patients with both severe and non-severe hypospadias exhibit mutations of MAMLD1. The aim of this work was to determine whether polymorphisms of MAMLD1 are a genetic risk factor for hypospadias. Material and methods This study included 150 hypospadias with a range of severities and 150 controls. Direct sequencing of the MAMLD1 coding exons and their flanking splice sites was performed. In silico secondary and tertiary structure prediction and accessibility of changed amino acids were evaluated using JPred, Netsurf and PHYRE software. Functional studies of the transactivation of haplotypes on Hes3 promoter were performed in vitro using cDNAs of missense variants of MAMLD1. Results The p.P286S polymorphism was identified in 17/150 patients and 12/150 controls (11.3% vs. 8.0%, p = 0.32). The p.N589S polymorphism was identified in 22/150 patients and 12/150 controls (14.6% vs. 8.0%, p = 0.068). The double polymorphism (S-S haplotype) was present in 16/150 patients and 6/150 controls (10.6% vs. 4.0%, p = 0.044, OR = 2.87, CI from 1.09 to 7.55). The association of polymorphisms consistently revealed a modification in the structure prediction or amino acid accessibility in all three in silico models. The P286S, N589S and P286S + N589S proteins did not exhibit reduced transactivating activity on Hes3 promoter. Conclusion Polymorphisms of MAMLD1 gene are frequent in patients with hypospadias. Although no change in transactivation was noted on Hes3 promoter, the in silico studies and the significantly increased incidence of the S-S haplotype in hypospadiac patients raise the hypothesis of a particular susceptibility conferred by these variants.

Accessory scrotum in the perineum

A case of accessory scrotum in a 2-day-old male infant is reported because of its rarity. An overview of sequences during the normal development of male external genitalia has been provided and the deranged mechanism resulting in this anomaly has been reviewed with hypotheses regarding etiology of accessory scrotum.

Growth and Development of Male External Genitalia

To provide estimates of normal variations in penile measurements and testicular volumes, and to establish reference ranges for clinical use. Cross-sectional, population-based study. Schools, kindergartens, and child care centers in different parts of Bulgaria. A population of 6200 clinically healthy white males aged 0 to 19 years. The study physician chose schools, kindergartens, and child care centers randomly and examined children at random until he reached the required number. Each of the 20 age groups (age range, 0-19 years) had an equal number of males (ie, 310). The mean (SD) values and fifth, 50th, and 95th percentiles of height (Siber Hegner anthropometer), weight (beam balance), testicular volume (Prader orchidometer), penile length (rigid tape), and penile circumference (measuring tape) from birth to 19 years of age. Testes did not show any increase in size until the onset of puberty at age 11 years, whereas penile growth was gradual after birth. However, both penile and testicular development demonstrated peak growth from 12 to 16 years of age, which coincided with the maximal male pubertal growth spurt. Data indicate an earlier pubertal development for this study population than that for a similar population several decades ago. Significant differences between urban and rural populations regarding penile length were also noticed. Our study provides the contemporary reference range values for height, weight, testicular volume, and penile length and circumference of males aged 0 to 19 years. Our data show that, even by the end of 20th century, there is still some acceleration of male pubertal development. For the first time are reported somatic differences in genitalia within a population between urban and rural representatives.

TAC3 and TACR3 mutations in familial hypogonadotropic hypogonadism reveal a key role for Neurokinin B in the central control of reproduction

The timely secretion of gonadal sex steroids is essential for the initiation of puberty, the postpubertal maintenance of secondary sexual characteristics and the normal perinatal development of male external genitalia. Normal gonadal steroid production requires the actions of the pituitary-derived gonadotropins, luteinizing hormone and follicle-stimulating hormone. We report four human pedigrees with severe congenital gonadotropin deficiency and pubertal failure in which all affected individuals are homozygous for loss-of-function mutations in TAC3 (encoding Neurokinin B) or its receptor TACR3 (encoding NK3R). Neurokinin B, a member of the substance P-related tachykinin family, is known to be highly expressed in hypothalamic neurons that also express kisspeptin, a recently identified regulator of gonadotropin-releasing hormone secretion. These findings implicate Neurokinin B as a critical central regulator of human gonadal function and suggest new approaches to the pharmacological control of human reproduction and sex hormone-related diseases.

Endocrine Disruptors, Genital Development, and Hypospadias

Hypospadias is one of the most common congenital anomalies in the United States, occurring in approximately 1 in 125 live male births. Embryological studies have demonstrated that, depending on where the urethral development arrests, the meatal opening can be anywhere along the shaft of the penis or, in more severe forms, within the scrotum or in the perineum. Currently, the only available treatment is surgery. If left uncorrected, especially in its severe form, there is risk of infertility and psychological effects, such as avoidance of intimate relationships. The cause of hypospadias is largely unknown; however, current epidemiology and laboratory studies have shed new light into the etiology of hypospadias. With recent advancements in molecular biology and microarray technology, it appears that hypospadias is potentially related to disrupted gene expression. Specifically, some of the environmental chemicals are acting as antiandrogens and interfere directly with the action of testosterone-related gene expression. In this paper, we briefly review the normal development of male external genitalia and the prevalence and environmental risk factors related to hypospadias. In addition, we discuss some of the recent laboratory findings that contribute to our current understanding of this disease.

Novel insertion frameshift mutation of the LH receptor gene: problematic clinical distinction of Leydig cell hypoplasia from enzyme defects primarily affecting testosterone biosynthesis

Leydig cell hypoplasia (LCH) is a rare autosomal recessive condition that interferes with normal development of male external genitalia in 46,XY individuals and is caused by inactivating mutations of the LH receptor gene. The clinical and biochemical diagnostic parameters of LCH are not always specific and may therefore show significant overlap with other causes of insufficient testicular steroid biosynthesis. We have studied a 46,XY newborn with completely female external genitalia and palpable testes. Due to an increased basal serum ratio of androstenedione/testosterone, 17 beta-hydroxysteroid dehydrogenase type 3 (17 beta-HSD 3) deficiency was initially suspected. DNA analysis of the corresponding HSD17B3 gene, however, showed no abnormalities in the entire coding region. In contrast, direct sequencing of the LH receptor gene revealed a novel homozygous single nucleotide insertion in exon 11 (codon A589fs) producing a frame shift in the open reading frame predicting for premature termination of translation 17 amino acids downstream. From the genetic perspective, this mutation represents the first frame shift mutation in the LH receptor gene ever reported to date. From the clinical standpoint, LCH should always be considered in the differential diagnosis as steroid profiles may not be informative. Therefore, molecular genetic analysis should be warranted for androgen biosynthesis defects in all cases.