Genetic, Maternal, and Environmental Risk Factors for Cryptorchidism: An Update

A massive alteration of gene expression in undescended testicles of dogs and the association of KAT6A variants with cryptorchidism

Cryptorchidism is the most common form of disorder of sex development in male dogs, but its hereditary predisposition is poorly elucidated. The gonadal transcriptome of nine unilaterally cryptorchid dogs and seven control dogs was analyzed using RNA-seq. Comparison between the scrotal and inguinal gonads of unilateral cryptorchid dogs revealed 8,028 differentially expressed genes (DEGs) (3,377 up-regulated and 4,651 down-regulated). A similar number of DEGs (7,619) was found by comparing the undescended testicles with the descended testicles of the control dogs. The methylation status of the selected DEGs was also analyzed, with three out of nine studied DEGs showing altered patterns. Bioinformatic analysis of the cDNA sequences revealed 20,366 SNP variants, six of which showed significant differences in allelic counts between cryptorchid and control dogs. Validation studies in larger cohorts of cryptorchid (n = 122) and control (n = 173) dogs showed that the TT genotype (rs850666472, p.Ala1230Val) and the AA genotype in 3'UTR (16:23716202G>A) in KATA6, responsible for acetylation of lysine 9 in histone H3, are associated with cryptorchidism (P = 0.0383). Both the transcript level of KAT6A and H3K9 acetylation were lower in undescended testes, and additionally, the acetylation depended on the genotypes in exon 17 and the 3'UTR. Our study showed that the massive alteration of the transcriptome in undescended testicles is not caused by germinal DNA variants in DEG regulatory sequences but is partly associated with an aberrant DNA methylation and H3K9 acetylation patterns. Moreover, variants of KAT6A can be considered markers associated with the risk of this disorder.

Diagnosis, Classification, and Contemporary Management of Undescended Testicles

This article provides a comprehensive review regarding undescended testicles and other related conditions. We have included background information summarizing variable clinical presentations, epidemiology, and the implications of undescended testis (UDT) on fertility and malignancy risk. This article has an emphasis on the approach to diagnosis and surgical management for the UDT. The purpose of this review is to provide readers with useful clinical tools for assessing and treating patients with cryptorchidism.

Acquired intra abdominal testis due to adhesions after necrotizing enterocolitis

Undescendent testis happens usually due to the stagnation during testicular descends. Stagnation of a testicle in the abdomen may be the target of adhesions with intestinal segments. Our case report a very rare variant of acquired intra-abdominal cryptorchidism due to adhesions after necrotizing enterocolitis. Newborn baby after NEC has a significant risk of developing intraperitoneal adhesions. In this report we will describe a case of previously palpable testis in the inguinal canal at neonatal age which was pulled inside the abdomen at seventh month of age through adhesions between test and the segment of sigmoid colon after NEC.

The RXFP2-PLC/PKC signaling pathway mediates INSL3-induced regulation of the proliferation, migration and apoptosis of mouse gubernacular cells

BACKGROUND

Testicular hypoplasia can affect the sexual and reproductive ability in adulthood, and even increase the risk of cancer. Abnormal development of the gubernaculum is one of the important factors of testicular hypoplasia. Therefore, a study of the structure and function of the gubernaculum is an important but neglected new breakthrough point for investigating the normal/abnormal development of the testis. Previous findings showed that Insulin like factor 3 (INSL3) is a key factor regulating the growth of gubernaculum, however, the mechanism by which INSL3 acts on the gubernaculum remains unknown. Therefore, we probed the mechanism associated with INSL3-induced the proliferation, migration, and apoptosis of gubernacular cells in mice.

METHODS

A culture cell model of neonatal mice gubernaculum is established by INSL3 intervention. We blocked PLC/PKC signaling pathway with U73122 pretreat to investigate the role of the PLC/PKC signaling pathway. The changes of cell proliferation, migration, and apoptosis were detected by molecular biological methods. In addition, the levels of PCNA and F-action were detected by immunofluorescence and western blotting.

RESULTS

We found that INSL3 can promote the proliferation and migration of gubernacular cells and inhibit their apoptosis, meanwhile, INSL3 significantly up-regulated PLC/PKC protein phosphorylation. However, treatment with the PLC/PKC signaling pathway inhibitor U73122 significantly inhibited these effects of INSL3. Besides, we found that INSL3 could up-regulate the protein expression level of PCNA and F-actin, while the PCNA and F-actin expression was significantly weakened after U73122 pretreatment.

CONCLUSIONS

This research revealed that INSL3 binding to RXFP2 may up-regulate the expression levels of PCNA and F-actin by activating the PLC/PKC signaling pathway to promote the proliferation and migration of gubernacular cells. It suggests that the RXFP2-PLC/PKC axis may serve as a novel molecular mechanism by which INSL3 regulates growth of the gubernaculum.

Loss of WNT4 in the gubernaculum causes unilateral cryptorchidism and fertility defects

Undescended testis (UDT) affects 6% of male births. Despite surgical correction, some men with unilateral UDT may experience infertility with the contralateral descended testis (CDT) showing no A-dark spermatogonia. To improve our understanding of the etiology of infertility in UDT, we generated a novel murine model of left unilateral UDT. Gubernaculum-specific Wnt4 knockout (KO) mice (Wnt4-cKO) were generated using retinoic acid receptor β2-cre mice and were found to have a smaller left-unilateral UDT. Wnt4-cKO mice with abdominal UDT had an increase in serum follicle-stimulating hormone and luteinizing hormone and an absence of germ cells in the undescended testicle. Wnt4-cKO mice with inguinal UDT had normal hormonal profiles, and 50% of these mice had no sperm in the left epididymis. Wnt4-cKO mice had fertility defects and produced 52% fewer litters and 78% fewer pups than control mice. Wnt4-cKO testes demonstrated increased expression of estrogen receptor α and SOX9, upregulation of female gonadal genes, and a decrease in male gonadal genes in both CDT and UDT. Several WNT4 variants were identified in boys with UDT. The presence of UDT and fertility defects in Wnt4-cKO mice highlights the crucial role of WNT4 in testicular development.

AKT3 and related molecules as potential biomarkers responsible for cryptorchidism and cryptorchidism-induced azoospermia

BACKGROUND

Cryptorchidism is a common congenital malformation strongly related to future oligospermia and male infertility. Normally functioning early-stage spermatogonia are vital to ensure fertility. The present study aimed to identify new differentially expressed genes (DEGs) associated with signaling pathways related to spermatogonial stem cell (SSC) maintenance during early spermatogenesis.

METHODS

GEO2R was used to screen for genes differentially regulated in cryptorchidism using mRNA expression profiling data in the GEO database. DAVID was used to perform GO and KEGG enrichment analysis of DEGs to analyze their functions. A protein-protein interaction (PPI) network of DEGs was constructed using the STRING database. The hub genes in the PPI networks were identified using Maximal Clique Centrality (MCC) in Cytohubba, and the top 50 genes were displayed as hub genes using Cytoscape software. Then, the miRNAs targeting hub genes were predicted using miRWalk and an mRNA-miRNA interaction network was constructed using Cytoscape. We took the intersection of these target miRNAs and the differentially expressed miRNAs identified from a non-coding RNA sequencing dataset, GSE149084. Furthermore, the intersected miRNAs and their predicted target genes were validated in the testicular tissue of rats with cryptorchidism.

RESULTS

A total of 474 DEGs were identified, most of which were annotated to the PI3K-AKT-mTOR signaling pathway. Hub genes related to the pathway were predicted to be targeted by 27 miRNAs. Further miRNA mining revealed that miRNA-7-5p and miRNA-519d-3p were both dysregulated in cryptorchidism patients. Further, we found that these two miRNAs were predicted with high confidence to share a common target gene, AKT3. In the testicular tissue of rats with cryptorchidism, miRNA-519d-3p was upregulated while miRNA-7-5p and AKT3 were downregulated. We also found that AKT3 plays an essential role in regulating SSC state through the PI3K-AKT-mTOR signaling pathway and that AKT3 is one of the key genes related to SSC self-renewal, proliferation, and differentiation.

CONCLUSIONS

The PI3K-AKT-mTOR signaling pathway functions in SSC maintenance, and alterations in this pathway may explain defects in spermatogenesis. AKT3-related miRNAs, including hsa-miR-7-5p and hsa-miR-519d-3p, might be responsible for cryptorchidism and cryptorchidism-induced azoospermia and serve as potential biomarkers.

Maternal rheumatoid arthritis and systemic lupus erythematosus and risk of cryptorchidism and hypospadias in boys: a Danish nationwide study

OBJECTIVES

RA and SLE are the most prevalent autoimmune rheumatic diseases affecting young women. Both diseases are characterized by systemic inflammation that may affect placental function and fetal development during pregnancy, and both diseases are associated with adverse pregnancy and child outcomes. We investigated the associations between maternal RA or SLE and the two genital malformations, cryptorchidism and hypospadias.

METHODS

In this nationwide register-based study including all male singleton live births in Denmark from 1995 to 2016, we assessed the occurrence of cryptorchidism and hypospadias according to the prenatal disease-state of the mothers. Using Cox proportional hazards models we calculated adjusted hazard ratios, accounting for varying age at diagnosis.

RESULTS

Among 690 240 boys, 1026 had a mother with RA and 352 had a mother with SLE. We found adjusted hazard ratios of 1.72 (95% CI: 1.15; 2.57) for cryptorchidism among boys born to mothers with RA and 1.46 (95% CI: 0.69; 3.06) for boys born to mothers with SLE, compared with the general population. As the number of hypospadias cases was low, multivariate analysis was not feasible. The crude hazard ratios were 0.51 (95% CI: 0.16; 1.58) and 1.00 (95% CI: 0.25; 4.03) for RA and SLE, respectively.

CONCLUSION

Boys born to mothers with RA had higher risk of cryptorchidism, compared with unexposed boys. Boys born to mothers with SLE showed a similar tendency, however with less precision of the estimate. No conclusion could be reached on the risk of hypospadias, due to the low number of events.

Sociodemographic and clinical factors associated with cryptorchidism in live births in Brazil: A 20-year analysis

Background: Cryptorchidism is a congenital disorder that causes an irregularity in the permanent or temporary descent of one or both testicles. In Brazil, there are no comprehensive studies describing the association of demographic, social, and clinical characteristics in relation to cryptorchidism. Objectives: This study aims to verify possible associations of clinical and sociodemographic characteristics in patients with cryptorchidism. Design and Methods: An analytical, descriptive and retrospective study was carried out based on secondary data of 5,168 live births with cryptorchidism recorded in the Live Birth Information System (SINASC), Brazil from 1999 to 2018. The socio-demographic factors analyzed were the geographic region, age, education and marital status of the mothers. The clinical factors analyzed were the duration and type of pregnancy. The place of birth was also analyzed as a secondary outcome. Results: This research analyzed all live births during the study period, in Brazil. The chance of cryptorchidism in the neonate is more common in women who become pregnant later (≥30 years of age) and with a higher level of education (≥8 years). The risk of cryptorchidism in relation to the federation units is higher in Paraiba, Pernambuco, Sergipe, Sao Paulo, and Santa Catarina. Regarding the clinical characteristics, the shorter pregnancies, which characterize premature births, are a risk for the appearance of cryptorchidism in the country. Conclusion: Thus, in this study, we found that sociodemographic and clinical factors have specific characteristics that predict cryptorchidism in newborns in Brazil.

Seminal Plasma Analysis of Oxidative Stress in Different Genitourinary Topographical Regions Involved in Reproductive Tract Disorders Associated with Genital Heat Stress

The pathophysiological mechanisms responsible for male subfertility/infertility caused by or complicated by genital heat stress remains unclear in many respects. Because seminal plasma creates the environment for the proper functioning of spermatozoa, in this study, we verified the associations among standard spermiograms, seminal biochemical parameters (neutral alpha-glucosidase, fructose, and citric acid) and oxidative stress markers (total antioxidant capacity, catalase activity, superoxide dismutase activity, and malondialdehyde concentration) in distinct entities associated with male infertility with and without long-time exposure to local hyperthermia. We demonstrated that men exposed to prolonged environmental or clinically recognized local heat stress in adulthood may suffer from dysregulation of seminal antioxidant components, which can be directly associated with epididymal and prostate function. The comparative analysis of the studied parameters showed numerous correlations among all biochemical parameters (particularly neutral alpha-glucosidase) with low standard semen quality in almost all the investigated infertile groups. In light of the data obtained in this originally designed study, we conclude that more attention should be paid to the epididymis and accessory gland function in subfertile and infertile men exposed to genital heat stress, especially in the context of novel treatment algorithms (targeted therapies).

Residential sources of pesticide exposure during pregnancy and the risks of hypospadias and cryptorchidism: the French ELFE birth cohort

OBJECTIVES

Prenatal occupational exposure to pesticides has been associated with male reproductive tract abnormalities. Little is known about the possible impact of non-occupational pesticide exposure on fetal and child development in the general population. Using data from a nationwide birth cohort, we aimed to assess the association between residential sources of prenatal pesticide exposure and the risks of hypospadias and cryptorchidism.

METHODS

Of the 9281 boys in ELFE (French Longitudinal Study of Children), the national French birth cohort, 53 were diagnosed with hypospadias and 137 with cryptorchidism. We assessed residential exposure sources from self-reported domestic use of eight types of pesticide products and French spatial land use data with acreage within a 1000 m radius around each family's home for 21 crop types. We used logistic regression modelling, adjusted for possible confounders that included estimated dietary pesticide intake. Multiple imputations were used to handle missing data.

RESULTS

An increased risk of hypospadias was associated with domestic pesticide use against fleas and ticks (OR=2.28, 95% CI 1.09 to 4.75); no associations were found between cryptorchidism and any domestic pesticide use. Slightly increased risks of cryptorchidism were observed in association with all crop acreages near homes during pregnancy, especially for orchards, and no association was observed for hypospadias.

CONCLUSIONS

Our results suggest a possible increased risk of hypospadias associated with prenatal use of some domestic pesticide products, likely to contain insecticides, and of cryptorchidism with nearby orchard acreage (crops repeatedly sprayed with pesticides). This work is limited by its modest number of cases.

RXFP2 as novel potential biomarker for abnormal differentiation induced by diethylstilbestrol in the gubernaculum of fetal mice

Environmental estrogens (EEs) have been correlated with abnormalities in the male urogenital system. However, the mechanism underlying the effect of these molecules remains unclear. In vitro and in vivo experiments were performed to examine the expression level and mechanism of relaxin family peptide receptor 2 (RXFP2) in the gubernaculum of fetal mice following diethylstilbestrol (DES) treatment. The in vivo results demonstrate that DES treatment increased the stillbirth rate gradually, decreased the gubernacular cone volume significantly, and disrupted the tissue structure, leading to incomplete testicular descent. In vitro experiments reveal that DES administration resulted in abnormal cellular morphology and structural disorder of gubernacular cells, which lost their original morphology in a dose-dependent manner. Moreover, DES-induced F-actin rearrangement and stress fiber formation in cultured cells. Protein quantitative analysis showed that the RXFP2 level in each experimental group was significantly lower than that of the normal group. In conclusion, DES affects the morphology and alters the gubernaculum structure, as well as the expression of RXFP2 protein. These data demonstrate that DES is toxic to gubernaculum in fetal mice, and that RXFP2 is associated with the abnormal gubernaculum morphology induced by DES. Taken together, these data suggest that RXFP2 may be a novel potential biomarker for abnormal differentiation of the gubernaculum.

We, the developing rete testis, efferent ducts, and Wolffian duct, all hereby agree that we need to connect

BACKGROUND

The mechanisms by which the rete testis joins the efferent ducts, which joins the Wolffian duct during development, are not known. Mouse and chick models have been helpful in identifying genes that are important for the development of each part, but genes have not been identified as to those that play a role in the joining of each part. Clinical implications of the failure of the male reproductive tract to form a fully functional conduit for spermatozoa are not trivial. Epididymal disjunction, the failure of the efferent ducts to join the testis, is one of several epididymal anomalies that have been observed in some boys who were cryptorchid at birth.

OBJECTIVE

A systematic review of studies focusing on the morphogenesis of the mesonephric duct and mesonephric tubules in different species, and identification of clinical issues should there be failure of these tissues to develop.

DESIGN

PubMed and GUDMAP databases, and review of books on kidney development were searched for studies reporting on the mechanisms of morphogenesis of the kidney and epididymis.

MAIN OUTCOMES MEASURE(S)

Gaps in our knowledge were identified, and hypotheses coupled with suggestions for future experiments were presented.

RESULTS

A total of 64 papers were identified as relevant, of which 53 were original research articles and 11 were book chapters and reviews covering morphogenesis and clinical issues. Investigators utilized multiple species including, human, mouse, chick, Xenopus, bovine, and sheep.

CONCLUSION

Fundamental understanding of the morphogenesis of the male reproductive tract is limited, especially the morphogenesis of the rete testis and efferent ducts. Therefore, it is not surprising that we do not understand how each part unites to form a whole. Only one mechanism of joining of one part of the tract to another was identified: the joining of the Wolffian duct to the cloaca via controlled apoptosis.

Impaired serum inhibin-B and number of germ cells in boys with cryptorchidism following heavily gestational maternal smoking

PURPOSE

A meta-analysis including 11,900 cases showed that maternal gestational smoking was associated with increased risk of cryptorchidism. The aim of study was to investigate whether a hormone profile of cryptorchid boys and a supplementing histopathological evaluation of testicular biopsies could add detailed knowledge to the impact of maternal gestational smoking on pathogenesis of cryptorchidism.

METHODS

601 cryptorchid boys aged 4 months to 14 years old were included. Because normal hormones have a pronounced age dependency, we compared results from boys whose mothers had smoked heavily (>10 cigarettes/day) during pregnancy with age matched cryptorchid controls of nonsmoking mothers (1:6). We studied: birthweight, germ-cell number/tubular cross section, frequency of germ cells positive for placental-like alkaline phosphatase (PLAP), gonadotropins and inhibin-B.

RESULTS

501 boys were sons of nonsmokers, 72 boys of intermittent smokers and 28 boys of heavy smokers. 39%, 44% and 61% respectively had bilateral cryptorchidism. Compared to age-matched cryptorchid controls of nonsmoking mothers, sons of heavy smokers had lower birthweight (p = 0.006), germ-cell number/tubular cross section (p = 0.009), frequency of germ cells positive for PLAP (p = 0.037) and inhibin-B (p = 0.042).

CONCLUSIONS

All findings could be associated with placental dysfunction with altered human chorionic gonadotropin production well described in women smoking during pregnancy.

TYPE OF STUDY

Prognosis study (prospective cohort study with >80% follow-up).

LEVEL OF EVIDENCE

Level 1.

Subphenotype meta-analysis of testicular cancer genome-wide association study data suggests a role for RBFOX family genes in cryptorchidism susceptibility

STUDY QUESTION

Can subphenotype analysis of genome-wide association study (GWAS) data from subjects with testicular germ cell tumor (TGCT) provide insight into cryptorchidism (undescended testis, UDT) susceptibility?

SUMMARY ANSWER

Suggestive intragenic GWAS signals common to UDT, TGCT case-case and TGCT case-control analyses occur in genes encoding RBFOX RNA-binding proteins (RBPs) and their neurodevelopmental targets.

WHAT IS KNOWN ALREADY

UDT is a strong risk factor for TGCT, but while genetic risk factors for TGCT are well-known, genetic susceptibility to UDT is poorly understood and appears to be more complex.

STUDY DESIGN, SIZE, DURATION

We performed a secondary subphenotype analysis of existing GWAS data from the Testicular Cancer Consortium (TECAC) and compared these results with our previously published UDT GWAS data, and with data previously acquired from studies of the fetal rat gubernaculum.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Studies from the National Cancer Institute (NCI), United Kingdom (UK) and University of Pennsylvania (Penn) that enrolled white subjects were the source of the TGCT GWAS data. We completed UDT subphenotype case-case (TGCT/UDT vs TGCT/non-UDT) and case-control (TGCT/UDT vs control), collectively referred to as 'TECAC' analyses, followed by a meta-analysis comprising 129 TGCT/UDT cases, 1771 TGCT/non-UDT cases, and 3967 unaffected controls. We reanalyzed our UDT GWAS results comprising 844 cases and 2718 controls by mapping suggestive UDT and TECAC signals (defined as P < 0.001) to genes using Ingenuity Pathway Analysis (IPA®). We compared associated pathways and enriched gene categories common to all analyses after Benjamini-Hochberg multiple testing correction, and analyzed transcript levels and protein expression using qRT-PCR and rat fetal gubernaculum confocal imaging, respectively.

MAIN RESULTS AND THE ROLE OF CHANCE

We found suggestive signals within 19 genes common to all three analyses, including RBFOX1 and RBFOX3, neurodevelopmental paralogs that encode RBPs targeting (U)GCATG-containing transcripts. Ten of the 19 genes participate in neurodevelopment and/or contribute to risk of neurodevelopmental disorders. Experimentally predicted RBFOX gene targets were strongly overrepresented among suggestive intragenic signals for the UDT (117 of 628 (19%), P = 3.5 × 10-24), TECAC case-case (129 of 711 (18%), P = 2.5 × 10-27) and TECAC case-control (117 of 679 (17%), P = 2 × 10-21) analyses, and a majority of the genes common to all three analyses (12 of 19 (63%), P = 3 × 10-9) are predicted RBFOX targets. Rbfox1, Rbfox2 and their encoded proteins are expressed in the rat fetal gubernaculum. Predicted RBFOX targets are also enriched among transcripts differentially regulated in the fetal gubernaculum during normal development (P = 3 × 10-31), in response to in vitro hormonal stimulation (P = 5 × 10-45) and in the cryptorchid LE/orl rat (P = 2 × 10-42).

LARGE SCALE DATA

GWAS data included in this study are available in the database of Genotypes and Phenotypes (dbGaP accession numbers phs000986.v1.p1 and phs001349.v1p1).

LIMITATIONS, REASONS FOR CAUTION

These GWAS data did not reach genome-wide significance for any individual analysis. UDT appears to have a complex etiology that also includes environmental factors, and such complexity may require much larger sample sizes than are currently available. The current methodology may also introduce bias that favors false discovery of larger genes.

WIDER IMPLICATIONS OF THE FINDINGS

Common suggestive intragenic GWAS signals suggest that RBFOX paralogs and other neurodevelopmental genes are potential UDT risk candidates, and potential TGCT susceptibility modifiers. Enrichment of predicted RBFOX targets among differentially expressed transcripts in the fetal gubernaculum additionally suggests a role for this RBP family in regulation of testicular descent. As RBFOX proteins regulate alternative splicing of Calca to generate calcitonin gene-related peptide, a protein linked to development and function of the gubernaculum, additional studies that address the role of these proteins in UDT are warranted.

STUDY FUNDING/COMPETING INTEREST(S)

The Eunice Kennedy Shriver National Institute for Child Health and Human Development (R01HD060769); National Center for Research Resources (P20RR20173), National Institute of General Medical Sciences (P20GM103464), Nemours Biomedical Research, the Testicular Cancer Consortium (U01CA164947), the Intramural Research Program of the NCI, a support services contract HHSN26120130003C with IMS, Inc., the Abramson Cancer Center at Penn, National Cancer Institute (CA114478), the Institute of Cancer Research, UK and the Wellcome Trust Case-Control Consortium (WTCCC) 2. None of the authors reports a conflict of interest.

Surgical Management of Undescended Testis - Timetable and Outcome: A Debate

Around 1.4-3.8% of boys in the Western world are operated because of cryptorchidism. This means that orchidopexy remains one of the most common surgical procedures performed in boys. As a consequence, several consensus reports, guidelines, and reviews dealing with the management of cryptorchidism have been published recently. Based on our research and 30 years' experience with the management of cryptorchidism, the intention of the present publication is to advise on the surgical management and comment on the expected outcome, especially with focus on the controversies related to guidelines and reviews. Except for late referral and waiting lists, which may be practical problems, there is no reason to postpone orchidopexy for nonsyndromic congenital cryptorchid testes beyond 6 months. There is good evidence that such strategy improves the fertility potential and decreases the risk of testicular cancer. In cases with genuine gonadotropin insufficiency, early surgical correction is not enough and adjuvant LH-RH treatment should be implemented to improve the fertility potential. Cryopreservation may be an option in case of treatment failure of adjuvant LH-RH. A prerequisite for such management includes serum hormone assessment and evaluation of testicular biopsies at orchidopexy. Ascended testes contribute to 20-60% of operative cases and should be treated when diagnosed.

Regional Variation in Androgen Receptor Expression and Biomechanical Properties May Contribute to Cryptorchidism Susceptibility in the LE/orl Rat

Background: The process of testicular descent requires androgen and insulin-like 3, hormones secreted by fetal Leydig cells. Knowledge concerning distinct and common functions of these hormones in regulating development of the fetal gubernaculum remains limited and/or conflicting. The current studies were designed to better define characteristics of androgen receptor (AR) expression, function and regulation, as well as the biomechanical properties of normal and cryptorchid gubernaculum during fetal development. Methods: We studied fetal gubernacula from Long Evans outbred (LE/wt) rats and an inbred (LE/orl) strain with an inherited form of cryptorchidism associated with an AR signaling defect. Gubernacular cells or whole organs obtained from LE/wt and LE/orl fetal gubernacula underwent AR immunostaining and quantitative image analysis. The effects of dihydrotestosterone (DHT) on AR expression, muscle fiber morphology, hyaluronan (HA) levels and glycosaminoglycan (GAG) content were measured in LE/wt gubernacula. Finally, the spatial mechanics of freshly harvested LE/wt and LE/orl fetal gubernacula were compared using micropipette aspiration. Results: AR is expressed in the nucleus of mesenchymal core, tip and cord cells of the embryonic (E) day 17 and 21 fetal gubernaculum, and is enhanced by DHT in primary cultures of gubernacular mesenchymal cells. Enhanced AR expression at the tip was observed in LE/wt but not LE/orl gubernacula. In in vitro studies of whole mount fetal gubernaculum, DHT did not alter muscle fiber morphology, HA content or GAG production. Progressive swelling with reduced cellular density of the LE/wt gubernaculum at E19-21 was associated with increased central stiffness in LE/wt but not in LE/orl fetuses. Conclusions: These data confirm nuclear AR expression in gubernacular mesenchyme with distal enhancement at the tip/cord region in LE/wt but not LE/orl rat fetuses. DHT enhanced cellular AR expression but had no major effects on muscle morphology or matrix composition in the rat fetal gubernaculum in vitro. Regional increased stiffness and decreased cell density between E19 and E21 were observed in LE/wt but not LE/orl fetal gubernacula. Developmental differences in cell-specific AR expression in LE/orl fetal gubernacula may contribute to the dysmorphism and aberrant function that underlies cryptorchidism susceptibility in this strain.

Cryptorchidism in Boys With Cerebral Palsy Is Associated With the Severity of Disease and With Co-Occurrence of Other Congenital Anomalies

BACKGROUND

Cryptorchidism is reported in 40-50% of small case series of cerebral palsy (CP) and attributed to hypothalamic-pituitary-gonadal axis abnormalities, intellectual disability (ID), or cremaster spasticity. We collected demographic and clinical data to define the frequency of cryptorchidism and clinical comorbidities in a large CP population.

METHODS

Electronic health record data were collected for all male patients ≥7 years of age seen in a large, multidisciplinary CP clinic between 2000 and 2016. Variables including age, testicular position, surgical findings, CP severity, birth history, and comorbidities were tested for association using univariable and stepwise backward logistic regression analyses.

RESULTS

Of 839 established patients, testis position was scrotal in 553, undescended in 185 (24%), retractile in 38 (5%), and undocumented in 63 cases. Cryptorchidism were diagnosed at a mean age of 5.8 years, with 20% documented as acquired, and testes were most commonly in the superficial inguinal pouch (41%) and associated with an inguinal hernia (56%). Severity was bilateral in 114/166 (69%) undescended and 24/36 (66%) retractile cases, respectively. Mean birth weight and the frequency of prematurity (55, 58, and 54%) and multiple birth (14, 13, and 9%) were not significantly different among the three groups. We observed a strong ordinal trend in the frequency of comorbidities, including quadriplegia, syndromic features/known genetic disease, intrauterine growth restriction (IUGR), death, brain malformations, seizures, gastrostomy, absent continence, ID and hearing, speech or visual impairment, with the retractile group holding the intermediate position for the majority. The stepwise multivariable analysis showed independent positive associations of cryptorchidism with quadriplegia, syndromic features/known genetic disease, hearing loss, and absent continence, and inverse associations with gestational age and multiple birth.

CONCLUSION

These data suggest that cryptorchidism is less common than previously reported in CP cases, but most strongly associated with quadriplegia. Delayed diagnosis may be related to an acquired condition or to the multiple additional functional deficits that occur in this population. Our data suggest that UDT and CP may both be components of malformation syndromes occurring in singleton births whose clinical features are more likely to include earlier delivery, IUGR, hearing loss, and/or global spasticity.

Anti-Müllerian Hormone and Testicular Function in Prepubertal Boys With Cryptorchidism

INTRODUCTION

The functional capacity of the testes in prepubertal boys with cryptorchidism before treatment has received very little attention. The assessment of testicular function at diagnosis could be helpful in the understanding of the pathophysiology of cryptorchidism and in the evaluation of the effect of treatment. Anti-Müllerian hormone is a well-accepted Sertoli cell biomarker to evaluate testicular function during childhood without the need for stimulation tests.

OBJECTIVE

The aim of the study was to assess testicular function in prepubertal children with cryptorchidism before orchiopexy, by determining serum anti-Müllerian hormone (AMH). We also evaluated serum gonadotropins and testosterone and looked for associations between testicular function and the clinical characteristics of cryptorchidism.

MATERIALS AND METHODS

We performed a retrospective, cross-sectional, analytical study at a tertiary pediatric public hospital. All clinical charts of patients admitted at the outpatient clinic, and recorded in our database with the diagnosis of cryptorchidism, were eligible. The main outcome measure of the study was the serum concentration of AMH. Secondary outcome measures were serum LH, FSH, and testosterone. For comparison, serum hormone levels from a normal population of 179 apparently normal prepubertal boys were used.

RESULTS

Out of 1,557 patients eligible in our database, 186 with bilateral and 124 with unilateral cryptorchidism were selected using a randomization software. Median AMH standard deviation score was below 0 in both the bilaterally and the unilaterally cryptorchid groups, indicating that testicular function was overall decreased in patients with cryptorchidism. Serum AMH was significantly lower in boys with bilateral cryptorchidism as compared with controls and unilaterally cryptorchid patients between 6 months and 1.9 years and between 2 and 8.9 years of age. Serum AMH below the normal range reflected testicular dysfunction in 9.5-36.5% of patients according to the age group in bilaterally cryptorchid boys and 6.3-16.7% in unilaterally cryptorchid boys. FSH was elevated in 8.1% and LH in 9.1% of boys with bilateral cryptorchidism, most of whom were anorchid. In patients with present testes, gonadotropins were only mildly elevated in less than 5% of the cases. Basal testosterone was mildly decreased in patients younger than 6 months old, and uninformative during childhood.

CONCLUSION

Prepubertal boys with cryptorchidism, especially those with bilaterally undescended gonads, have decreased AMH production. Although serum AMH may fall within the normal range, there is a considerable prevalence of testicular dysfunction during childhood in this frequent condition.

On the descent of the epididymo-testicular unit, cryptorchidism, and prevention of infertility

This comprehensive review provides in-depth coverage of progress made in understanding the molecular mechanisms underlying cryptorchidism, a frequent pathology first described in about 1786 by John Hunter. The first part focuses on the physiology, embryology, and histology of epididymo-testicular descent. In the last 20 years epididymo-testicular descent has become the victim of schematic drawings with an unjustified rejection of valid histological data. This part also includes discussion on the roles of gonadotropin-releasing hormone, fibroblast growth factors, Müllerian inhibiting substance, androgens, inhibin B, and insulin-like 3 in epididymo-testicular descent. The second part addresses the etiology and histology of cryptorchidism as well as the importance of mini-puberty for normal fertility development. A critical view is presented on current clinical guidelines that recommend early orchidopexy alone as the best possible treatment. Finally, by combining classical physiological information and the output of cutting-edge genomics data into a complete picture the importance of hormonal treatment in preventing cryptorchidism-induced infertility is underscored.

Smoking and its association with cryptorchidism in Down syndrome

INTRODUCTION

Cryptorchidism is a common and prevalent condition in patients with Down syndrome. Environmental factors, such as smoking, can be associated with malformations during fetal development. The study of the prevalence of cryptorchidism and its association with parental tobacco use in Down syndrome can contribute to alert health care professionals, patients and family members regarding the prevention of the harms caused by cryptorchidism and its possible predisposing factors.

OBJECTIVE

To evaluate the prevalence of cryptorchidism in Down syndrome and its association with maternal and paternal smoking.

METHOD

Forty (40) patients of a public clinic specialized in Down syndrome were evaluated, using a semi-structured questionnaire for evaluation of antecedents and sociodemographic characteristics, as well as physical and complementary examinations.

RESULTS

Cryptorchidism was observed in 27.5% of the patients (95CI 15.98-42.96). Of these, 55% (5/9) were the children of mothers who smoked during pregnancy, and 19.35% (6/31) were the children of mothers who did not smoke during pregnancy (OR = 5.26 [95CI 1.06-25.41]; p=0.032). Similarly, paternal smoking was also observed in greater frequency among the parents of cryptorchid patients compared with subjects with descended testis, 63.36% (7/11) and 31.03% (9/29), respectively (OR = 3.89 [95CI 0.91-16.73]; p=0.060).

CONCLUSION

The prevalence of cryptorchidism is high in patients with Down syndrome. We can show a strong association between smoking parents and the occurrence of cryptorchidism, especially when it comes to maternal smoking.

Exomic and Epigenomic Analyses in a Pair of Monozygotic Twins Discordant for Cryptorchidism

Cryptorchidism represents one of the most common human congenital anomalies. In most cases, its etiology remains unclear and seems to be multifactorial. In the present study, a pair of monozygotic twins discordant for cryptorchidism was identified. Twin zygosity was confirmed by microsatellite genotyping. Whole exome sequencing and methylated DNA immunoprecipitation sequencing (MeDIP-Seq) of DNA extract from leucocytes were performed to, respectively, evaluate their exomes and epigenomes. No differences in exome sequencing data were found between the twins after validation. MeDIP-Seq analysis detected 5,410 differentially hypermethylated genes and 2,383 differentially hypomethylated genes. Bioinformatic analysis showed that these genes belonged to several biological processes and signaling pathways, including regulation of actin cytoskeleton, which has been previously implicated in the etiology of cryptorchidism. The findings of the present study suggest that non-genetic factors might contribute to the pathogenesis of cryptorchidism.

Altered secretion of Sertoli cells hormones in 2-year-old prepubertal cryptorchid boys: a cross-sectional study

In cryptorchid boys, failures in germ cell development have been clearly established. Some studies reported some abnormalities in Sertoli cells morphology but the results regarding their endocrine secretion remain controversial. To compare testicular hormone levels in young boys with and without cryptorchidism, we performed a cross-sectional hospital-based study. From surgery appointment records, we identified a case group of boys with unilateral or bilateral cryptorchidism and a control group undergoing dental care, minor osteoarticular or dermal surgery. Blood samples were withdrawn during the surgical procedure to perform testosterone, inhibin B and anti-müllerian hormone (AMH) immunoassays. We included 27 cryptorchid boys and 27 controls aged of 26.6 vs. 24.2 months, respectively (p = 0.172) far from the post-natal mini-puberty and the corresponding hormonal surges. Age-adjusted AMH and inhibin B levels were significantly lower in cryptorchid than in control boys (AMH: 87 ng/mL vs. 135 ng/mL; p = 0.009, inhibin B: 97 pg/mL vs. 133 pg/mL; p = 0.019, respectively). Moreover, AMH and inhibin B levels were significantly lower in the bilateral cryptorchid subgroup, being 50% lower than in the controls (p = 0.011 and 0.019, respectively) and while both hormones levels were independent in controls, they became strongly correlated in bilateral cryptorchid boys (R² = 0.75, p = 0.001). In addition, testosterone levels were still detectable in some boys, with significantly lower levels in cryptorchid group than in controls. Overall, 2-year-old cryptorchid patients presented a simultaneous and significant drop in AMH and inhibin B levels, suggesting a functional defect of Sertoli cells. This deficiency appeared more pronounced in bilateral cryptorchidism and thus, regarding the pivotal role of Sertoli cells in germ cell development, it may explain the compromised fertility found later in men born with such a malformation.

Genetic analysis of HOXA11 gene in Chinese patients with cryptorchidism

Cryptorchidism is the most common congenital anomaly in male children. Its aetiology remains unknown in the majority of cases. Because HOXA11 plays a vital role in regulating testicular descent, genetic variants in HOXA11 genes may contribute to the risk of cryptorchidism. In this study, mutation analysis was performed on the HOXA11 gene in a cohort of 89 patients with cryptorchidism. Furthermore, an association analysis of the HOXA11 tag single nucleotide polymorphism rs6461992 was performed in 168 patients with unilateral cryptorchidism and 193 controls. No pathogenic mutations were found. A significant difference in genotype and allele distribution was detected between cases and controls (p = .029 and .022 respectively). These results suggest that mutations in the coding sequence of HOXA11 might not be a common cause of cryptorchidism, while common polymorphisms in the HOXA11 gene might contribute to the risk of developing unilateral cryptorchidism.