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Abstract
Cryptorchidism, i.e., undescended testis, is one of the most common genital malformations in newborn male babies. The birth rate of cryptorchidism varies from 1.6 to 9.0 %. Etiology of disrupted testicular descent is complex and predisposing causes include genetic, hormonal, environmental, lifestyle and maternal factors. Testicular descent occurs in two major steps and testicular hormones and normal function of hypothalamic-pituitary-testicular axis are important for normal descent. Several gene mutations are associated with syndromic cryptorchidism but they are rarely found in boys with isolated undescended testis. Testicular regression can also cause an empty scrotum. Normal male genital phenotype indicates that the boy has had functioning testis during development. Torsion of the testis can cause testicular regression but in many cases the reason for vanishing testis remains elusive. In this narrative review we discuss genetics of cryptorchidism and testicular regression.
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Affiliation(s)
- Heidi P Elamo
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, 20520 Turku, Finland; Centre for Population Health Research, University of Turku and Turku University Hospital, Turku, Finland.
| | - Helena E Virtanen
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, 20520 Turku, Finland; Centre for Population Health Research, University of Turku and Turku University Hospital, Turku, Finland.
| | - Jorma Toppari
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, 20520 Turku, Finland; Centre for Population Health Research, University of Turku and Turku University Hospital, Turku, Finland; Department of Pediatrics, Turku University Hospital, Turku, Finland.
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2
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Wang Y, Li J, Kolon TF, Olivant Fisher A, Figueroa TE, BaniHani AH, Hagerty JA, Gonzalez R, Noh PH, Chiavacci RM, Harden KR, Abrams DJ, Stabley D, Kim CE, Sol-Church K, Hakonarson H, Devoto M, Barthold JS. Genomic copy number variation association study in Caucasian patients with nonsyndromic cryptorchidism. BMC Urol 2016; 16:62. [PMID: 27769252 PMCID: PMC5073740 DOI: 10.1186/s12894-016-0180-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 10/14/2016] [Indexed: 11/10/2022] Open
Abstract
Background Copy number variation (CNV) is a potential contributing factor to many genetic diseases. Here we investigated the potential association of CNV with nonsyndromic cryptorchidism, the most common male congenital genitourinary defect, in a Caucasian population. Methods Genome wide genotyping were performed in 559 cases and 1772 controls (Group 1) using Illumina HumanHap550 v1, HumanHap550 v3 or Human610-Quad platforms and in 353 cases and 1149 controls (Group 2) using the Illumina Human OmniExpress 12v1 or Human OmniExpress 12v1-1. Signal intensity data including log R ratio (LRR) and B allele frequency (BAF) for each single nucleotide polymorphism (SNP) were used for CNV detection using PennCNV software. After sample quality control, gene- and CNV-based association tests were performed using cleaned data from Group 1 (493 cases and 1586 controls) and Group 2 (307 cases and 1102 controls) using ParseCNV software. Meta-analysis was performed using gene-based test results as input to identify significant genes, and CNVs in or around significant genes were identified in CNV-based association test results. Called CNVs passing quality control and signal intensity visualization examination were considered for validation using TaqMan CNV assays and QuantStudio® 3D Digital PCR System. Results The meta-analysis identified 373 genome wide significant (p < 5X10−4) genes/loci including 49 genes/loci with deletions and 324 with duplications. Among them, 17 genes with deletion and 1 gene with duplication were identified in CNV-based association results in both Group 1 and Group 2. Only 2 genes (NUCB2 and UPF2) containing deletions passed CNV quality control in both groups and signal intensity visualization examination, but laboratory validation failed to verify these deletions. Conclusions Our data do not support that structural variation is a major cause of nonsyndromic cryptorchidism. Electronic supplementary material The online version of this article (doi:10.1186/s12894-016-0180-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yanping Wang
- Nemours Biomedical Research, Nemours /Alfred I. duPont Hospital for Children, Wilmington, DE, 19803, USA
| | - Jin Li
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Thomas F Kolon
- Division of Urology, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Alicia Olivant Fisher
- Nemours Biomedical Research, Nemours /Alfred I. duPont Hospital for Children, Wilmington, DE, 19803, USA
| | - T Ernesto Figueroa
- Division of Urology, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, 19803, USA
| | - Ahmad H BaniHani
- Division of Urology, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, 19803, USA
| | - Jennifer A Hagerty
- Division of Urology, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, 19803, USA
| | - Ricardo Gonzalez
- Division of Urology, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, 19803, USA.,Present address: Auf der Bult Kinder- und Jugendkrankenhaus, Hannover, Germany
| | - Paul H Noh
- Division of Urology, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, 19803, USA.,Present address: Division of Pediatric Urology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Rosetta M Chiavacci
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Kisha R Harden
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Debra J Abrams
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Deborah Stabley
- Nemours Biomedical Research, Nemours /Alfred I. duPont Hospital for Children, Wilmington, DE, 19803, USA
| | - Cecilia E Kim
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Katia Sol-Church
- Nemours Biomedical Research, Nemours /Alfred I. duPont Hospital for Children, Wilmington, DE, 19803, USA
| | - Hakon Hakonarson
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.,Division of Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.,Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Marcella Devoto
- Division of Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.,Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.,Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.,Department of Molecular Medicine, Sapienza University, Rome, Italy
| | - Julia Spencer Barthold
- Nemours Biomedical Research, Nemours /Alfred I. duPont Hospital for Children, Wilmington, DE, 19803, USA. .,Division of Urology, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, 19803, USA.
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Niedzielski JK, Oszukowska E, Słowikowska-Hilczer J. Undescended testis - current trends and guidelines: a review of the literature. Arch Med Sci 2016; 12:667-77. [PMID: 27279862 PMCID: PMC4889701 DOI: 10.5114/aoms.2016.59940] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 02/26/2015] [Indexed: 11/17/2022] Open
Abstract
The best mode of undescended testis (UDT) treatment remains controversial. However, knowledge gained from randomized controlled studies and meta-analyses allowed different groups of researchers to set out guidelines on management of patients with UDT. The authors reviewed recent literature and came to the following conclusions: (1) Hormonal treatment is not recommended, considering both the immediate results (only 15-20% of retained testes descend) and the possible long-term adverse effects on spermatogenesis. (2) Surgery is the treatment of choice; orchiopexy is successful in about 95% of UDT, with a low rate of complications (about 1%). (3) Orchiopexy should be performed between 12 and 18 months of age, or at first contact if diagnosed later.
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Affiliation(s)
- Jerzy K. Niedzielski
- Department of Pediatric Surgery and Urology, Medical University of Lodz, Lodz, Poland
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Barthold JS, Wang Y, Kolon TF, Kollin C, Nordenskjöld A, Olivant Fisher A, Figueroa TE, BaniHani AH, Hagerty JA, Gonzaléz R, Noh PH, Chiavacci RM, Harden KR, Abrams DJ, Kim CE, Li J, Hakonarson H, Devoto M. Pathway analysis supports association of nonsyndromic cryptorchidism with genetic loci linked to cytoskeleton-dependent functions. Hum Reprod 2015. [PMID: 26209787 DOI: 10.1093/humrep/dev180] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
STUDY QUESTION What are the genetic loci that increase susceptibility to nonsyndromic cryptorchidism, or undescended testis? SUMMARY ANSWER A genome-wide association study (GWAS) suggests that susceptibility to cryptorchidism is heterogeneous, with a subset of suggestive signals linked to cytoskeleton-dependent functions and syndromic forms of the disease. WHAT IS KNOWN ALREADY Population studies suggest moderate genetic risk of cryptorchidism and possible maternal and environmental contributions to risk. Previous candidate gene analyses have failed to identify a major associated locus, although variants in insulin-like 3 (INSL3), relaxin/insulin-like family peptide receptor 2 (RXFP2) and other hormonal pathway genes may increase risk in a small percentage of patients. STUDY DESIGN, SIZE, DURATION This is a case-control GWAS of 844 boys with nonsyndromic cryptorchidism and 2718 control subjects without syndromes or genital anomalies, all of European ancestry. PARTICIPANTS/MATERIALS, SETTING, METHODS All boys with cryptorchidism were diagnosed and treated by a pediatric specialist. In the discovery phase, DNA was extracted from tissue or blood samples and genotyping performed using the Illumina HumanHap550 and Human610-Quad (Group 1) or OmniExpress (Group 2) platform. We imputed genotypes genome-wide, and combined single marker association results in meta-analyses for all cases and for secondary subphenotype analyses based on testis position, laterality and age, and defined genome-wide significance as P = 7 × 10(-9) to correct for multiple testing. Selected markers were genotyped in an independent replication group of European cases (n = 298) and controls (n = 324). We used several bioinformatics tools to analyze top (P < 10(-5)) and suggestive (P < 10(-3)) signals for significant enrichment of signaling pathways, cellular functions and custom gene lists after multiple testing correction. MAIN RESULTS AND THE ROLE OF CHANCE In the full analysis, we identified 20 top loci, none reaching genome-wide significance, but one passing this threshold in a subphenotype analysis of proximal testis position (rs55867206, near SH3PXD2B, odds ratio = 2.2 (95% confidence interval 1.7, 2.9), P = 2 × 10(-9)). An additional 127 top loci emerged in at least one secondary analysis, particularly of more severe phenotypes. Cytoskeleton-dependent molecular and cellular functions were prevalent in pathway analysis of suggestive signals, and may implicate loci encoding cytoskeletal proteins that participate in androgen receptor signaling. Genes linked to human syndromic cryptorchidism, including hypogonadotropic hypogonadism, and to hormone-responsive and/or differentially expressed genes in normal and cryptorchid rat gubernaculum, were also significantly overrepresented. No tested marker showed significant replication in an independent population. The results suggest heterogeneous, multilocus and potentially multifactorial susceptibility to nonsyndromic cryptorchidism. LIMITATIONS, REASONS FOR CAUTION The present study failed to identify genome-wide significant markers associated with cryptorchidism that could be replicated in an independent population, so further studies are required to define true positive signals among suggestive loci. WIDER IMPLICATIONS OF THE FINDINGS As the only GWAS to date of nonsyndromic cryptorchidism, these data will provide a basis for future efforts to understand genetic susceptibility to this common reproductive anomaly and the potential for additive risk from environmental exposures. STUDY FUNDING/COMPETING INTERESTS This work was supported by R01HD060769 (the Eunice Kennedy Shriver National Institute for Child Health and Human Development (NICHD)), P20RR20173 (the National Center for Research Resources (NCRR), currently P20GM103464 from the National Institute of General Medical Sciences (NIGMS)), an Institute Development Fund to the Center for Applied Genomics at The Children's Hospital of Philadelphia, and Nemours Biomedical Research. The authors have no competing interests to declare.
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Affiliation(s)
- Julia Spencer Barthold
- Nemours Biomedical Research, Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA Division of Urology, Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA
| | - Yanping Wang
- Nemours Biomedical Research, Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA
| | - Thomas F Kolon
- Division of Urology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Claude Kollin
- Department of Women's and Children's Health, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Agneta Nordenskjöld
- Department of Women's and Children's Health, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Alicia Olivant Fisher
- Nemours Biomedical Research, Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA
| | - T Ernesto Figueroa
- Division of Urology, Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA
| | - Ahmad H BaniHani
- Division of Urology, Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA
| | - Jennifer A Hagerty
- Division of Urology, Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA
| | - Ricardo Gonzaléz
- Division of Urology, Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA Present address: Auf der Bult Kinder- und Jugendkrankenhaus, Hannover, Germany
| | - Paul H Noh
- Division of Urology, Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA Present address: Division of Pediatric Urology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Rosetta M Chiavacci
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Kisha R Harden
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Debra J Abrams
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Cecilia E Kim
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Jin Li
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Hakon Hakonarson
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA Division of Genetics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Marcella Devoto
- Division of Genetics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA Department of Molecular Medicine, Sapienza University, Rome, Italy
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Cannistraci CV, Ogorevc J, Zorc M, Ravasi T, Dovc P, Kunej T. Pivotal role of the muscle-contraction pathway in cryptorchidism and evidence for genomic connections with cardiomyopathy pathways in RASopathies. BMC Med Genomics 2013; 6:5. [PMID: 23410028 PMCID: PMC3626861 DOI: 10.1186/1755-8794-6-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 02/06/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cryptorchidism is the most frequent congenital disorder in male children; however the genetic causes of cryptorchidism remain poorly investigated. Comparative integratomics combined with systems biology approach was employed to elucidate genetic factors and molecular pathways underlying testis descent. METHODS Literature mining was performed to collect genomic loci associated with cryptorchidism in seven mammalian species. Information regarding the collected candidate genes was stored in MySQL relational database. Genomic view of the loci was presented using Flash GViewer web tool (http://gmod.org/wiki/Flashgviewer/). DAVID Bioinformatics Resources 6.7 was used for pathway enrichment analysis. Cytoscape plug-in PiNGO 1.11 was employed for protein-network-based prediction of novel candidate genes. Relevant protein-protein interactions were confirmed and visualized using the STRING database (version 9.0). RESULTS The developed cryptorchidism gene atlas includes 217 candidate loci (genes, regions involved in chromosomal mutations, and copy number variations) identified at the genomic, transcriptomic, and proteomic level. Human orthologs of the collected candidate loci were presented using a genomic map viewer. The cryptorchidism gene atlas is freely available online: http://www.integratomics-time.com/cryptorchidism/. Pathway analysis suggested the presence of twelve enriched pathways associated with the list of 179 literature-derived candidate genes. Additionally, a list of 43 network-predicted novel candidate genes was significantly associated with four enriched pathways. Joint pathway analysis of the collected and predicted candidate genes revealed the pivotal importance of the muscle-contraction pathway in cryptorchidism and evidence for genomic associations with cardiomyopathy pathways in RASopathies. CONCLUSIONS The developed gene atlas represents an important resource for the scientific community researching genetics of cryptorchidism. The collected data will further facilitate development of novel genetic markers and could be of interest for functional studies in animals and human. The proposed network-based systems biology approach elucidates molecular mechanisms underlying co-presence of cryptorchidism and cardiomyopathy in RASopathies. Such approach could also aid in molecular explanation of co-presence of diverse and apparently unrelated clinical manifestations in other syndromes.
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Affiliation(s)
- Carlo V Cannistraci
- Integrative Systems Biology Laboratory, Biological and Environmental Sciences and Engineering Division, Computational Bioscience Research Center, King Abdullah University for Science and Technology, Thuwal, Saudi Arabia.
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Abstract
Complete testicular descent is a sign of, and a prerequisite for, normal testicular function in adult life. The process of testis descent is dependent on gubernacular growth and reorganization, which is regulated by the Leydig cell hormones insulin-like peptide 3 (INSL3) and testosterone. Investigation of the role of INSL3 and its receptor, relaxin-family peptide receptor 2 (RXFP2), has contributed substantially to our understanding of the hormonal control of testicular descent. Cryptorchidism is a common congenital malformation, which is seen in 2-9% of newborn boys, and confers an increased risk of infertility and testicular cancer in adulthood. Although some cases of isolated cryptorchidism in humans can be ascribed to known genetic defects, such as mutations in INSL3 or RXFP2, the cause of cryptorchidism remains unknown in most patients. Several animal and human studies are currently underway to test the hypothesis that in utero factors, including environmental and maternal lifestyle factors, may be involved in the etiology of cryptorchidism. Overall, the etiology of isolated cryptorchidism seems to be complex and multifactorial, involving both genetic and nongenetic components.
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The development and anatomy of the gubernaculum in Hoxa11 knockout mice. J Pediatr Surg 2011; 46:387-92. [PMID: 21292093 DOI: 10.1016/j.jpedsurg.2010.11.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Accepted: 11/04/2010] [Indexed: 11/23/2022]
Abstract
BACKGROUND The gubernaculum is central to testicular descent, with recent evidence suggesting that it elongates to the scrotum like a limb bud. Homeobox (Hox) genes involved in limb bud outgrowth are expressed within the gubernaculum. Mice with homozygous Hoxa11 gene deletions have bilateral cryptorchidism. This study investigated the precise anatomical effects of Hoxa11 mutation on the mouse gubernaculum. METHODS The pelvises of postnatal mice (n = 46; days 1-10) with Hoxa11 knockout (n = 19), heterozygotes (n = 11), and wild-type (n = 16) mice were serially sectioned and stained with hematoxylin and eosin. Immunohistochemistry was performed for the presence of desmin. RESULTS Hoxa11 mutant mice had intraabdominal cryptorchid testes and highly convoluted vas deferentia. The gubernacular bulbs were abnormal, with no "outgrowth" and persistence of the prenatal "swelling reaction." Desmin immunostaining revealed the lack of undifferentiated mesenchymal cells usually seen as a "swirl" within the bulb and decreased formation of cremaster muscle. CONCLUSIONS Hoxa11 may be involved in forming the growth center seen as the "swirl" of mesenchyme within the gubernacular bulb, consistent with these cells being required for gubernacular elongation during testicular descent. Hoxa11 mutations may well contribute to failure of gubernacular migration in boys with cryptorchidism.
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[Cryptorchidism: from physiopathology to infertility]. ACTA ACUST UNITED AC 2010; 38:588-99. [PMID: 20870444 DOI: 10.1016/j.gyobfe.2010.08.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Accepted: 03/30/2010] [Indexed: 11/24/2022]
Abstract
Cryptorchidism is a defect of testicular descent. Hormonal, genetic and environmental factors might also contribute to the aetiology of cryptorchidism and its increased incidence in recent years in industrialised countries. Cryptorchidism itself might be considered a complex disease. This testicular pathology represents the best-characterized risk factor for reduced fertility and testicular cancer. The purpose of this review is to better understand physiopathology and mechanisms of infertility in men with history of cryptorchidism.
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Abstract
Cryptorchidism is a common genital anomaly diagnosed at birth or during childhood. Genetic and/or environmental factors that alter expression or function of hormones crucial for testicular descent, insulin-like 3, and testosterone, may contribute to cryptorchidism. When identified at birth, surgical treatment is indicated by 6 months of age if testes fail to descend, or at the time of diagnosis in older children. A laparoscopic approach is preferred for abdominal testes. Early surgical therapy may reduce the risk of subfertility and/or malignancy.
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Kojima Y, Mizuno K, Kohri K, Hayashi Y. Advances in molecular genetics of cryptorchidism. Urology 2009; 74:571-8. [PMID: 19589567 DOI: 10.1016/j.urology.2009.04.037] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Revised: 04/07/2009] [Accepted: 04/13/2009] [Indexed: 10/20/2022]
Abstract
Cryptorchidism is the most common congenital disorder in boys; one major complication of this disorder is male infertility. Androgens are key hormones to complete testicular descent; therefore, impaired fetal androgen action can result in this anomaly; its molecular etiology, however, remains unknown. Recent molecular approaches might provide an opportunity to identify not only candidate genes but also several predictive markers of future fertility. The purpose of this review is to summarize the recent insight into the genetic pathway of testicular descent and the molecular etiology of isolated cryptorchidism, and discuss the prospects of treatment to achieve future fertility in such patients.
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Affiliation(s)
- Yoshiyuki Kojima
- Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan
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Abstract
PURPOSE OF REVIEW Nonsyndromic cryptorchidism or undescended testis is a structural defect of infants and children whose etiology is unknown but likely related to a combination of genetic susceptibility and environmental factors. This review will focus on factors that may contribute to the etiology of this common and complex disease. RECENT FINDINGS The incidence of cryptorchidism is estimated to be 2-4% or higher in some populations. Data suggesting increasing prevalence are conflicting, possibly related to problems with diagnostic accuracy. Increased risk of cryptorchidism in first-degree relatives suggests a significant genetic contribution to susceptibility. Sequence variants within key candidate genes, such as insulin-like 3 and relaxin/insulin-like family peptide receptor 2, in cases of nonsyndromic cryptorchidism are infrequent and of unclear significance. Epidemiological data suggest that fetal growth restriction, maternal factors such as smoking, alcohol use and gestational diabetes, and exposure to environmental chemicals may contribute to risk, although data are inconsistent. SUMMARY The available evidence suggests a significant genetic contribution to cryptorchidism susceptibility that may be modulated by environmental risk factors. Additional studies are needed to define these factors, their complex interaction and their effects on testicular development and descent.
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Foresta C, Zuccarello D, Garolla A, Ferlin A. Role of hormones, genes, and environment in human cryptorchidism. Endocr Rev 2008; 29:560-80. [PMID: 18436703 DOI: 10.1210/er.2007-0042] [Citation(s) in RCA: 176] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cryptorchidism is the most frequent congenital birth defect in male children (2-4% in full-term male births), and it has the potential to impact the health of the human male. In fact, although it is often considered a mild malformation, it represents the best-characterized risk factor for reduced fertility and testicular cancer. Furthermore, some reports have highlighted a significant increase in the prevalence of cryptorchidism over the last few decades. Etiology of cryptorchidism remains for the most part unknown, and cryptorchidism itself might be considered a complex disease. Major regulators of testicular descent from intraabdominal location into the bottom of the scrotum are the Leydig-cell-derived hormones testosterone and insulin-like factor 3. Research on possible genetic causes of cryptorchidism has increased recently. Abundant animal evidence supports a genetic cause, whereas the genetic contribution to human cryptorchidism is being elucidated only recently. Mutations in the gene for insulin-like factor 3 and its receptor and in the androgen receptor gene have been recognized as causes of cryptorchidism in some cases, but some chromosomal alterations, above all the Klinefelter syndrome, are also frequently involved. Environmental factors acting as endocrine disruptors of testicular descent might also contribute to the etiology of cryptorchidism and its increased incidence in recent years. Furthermore, polymorphisms in different genes have recently been investigated as contributing risk factors for cryptorchidism, alone or by influencing susceptibility to endocrine disruptors. Obviously, the interaction of environmental and genetic factors is fundamental, and many aspects have been clarified only recently.
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Affiliation(s)
- Carlo Foresta
- University of Padova, Department of Histology, Microbiology and Medical Biotechnologies, Section of Clinical Pathology and Centre for Male Gamete Cryopreservation, Via Gabelli 63, 35121 Padova, Italy.
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Lalwani S, Wu HH, Reindollar RH, Gray MR. HOXA10 mutations in congenital absence of uterus and vagina. Fertil Steril 2008; 89:325-30. [PMID: 17482600 DOI: 10.1016/j.fertnstert.2007.03.033] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2006] [Revised: 03/06/2007] [Accepted: 03/07/2007] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To analyze the HOXA10 genes in CAUV patients for mutations. Congenital absence of the uterus and vagina (CAUV) is the most extreme female reproductive tract developmental defect known. The HOXA10 gene is expressed in the developing and adult uterus. Female mice with loss-of-function Hoxa10 gene mutations have anteriorly directed homeotic transformations of the uterus. Because the HOXA10 gene is expressed in the embryonic paramesonephric (Müllerian) ducts, abnormally low expression by mutant HOXA10 genes might cause CAUV. This hypothesis was tested by analyzing the HOXA10 genes in CAUV patients for mutations. DESIGN Case-control study. SETTING Academic reproductive endocrinology and infertility practice. PATIENT(S) Blood samples were obtained from 26 patients with CAUV and 30 normal controls. INTERVENTION(S) DNA samples prepared from blood leukocytes were used as templates for polymerase chain reaction (PCR) amplification of DNA fragments from the HOXA10 gene. The gene fragments were tested for DNA sequence differences using denaturing gradient gel electrophoresis (DGGE). MAIN OUTCOME MEASURE(S) To detect DNA sequence differences between patients with CAUV and normal controls. RESULT(S) No DNA sequence differences were found in either patients with CAUV or normal controls in either of the two protein-coding exons of the HOXA10 gene. CONCLUSION(S) Because no HOXA10 gene mutations were found in 26 patients from 25 unrelated families, germ- line mutations in the HOXA10 gene are not a common cause of CAUV.
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Affiliation(s)
- Sasmira Lalwani
- Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Tufts-New England Medical Center, Boston, Massachusetts 02111, USA.
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Ferlin A, Zuccarello D, Garolla A, Selice R, Foresta C. Hormonal and genetic control of testicular descent. Reprod Biomed Online 2008; 15:659-65. [PMID: 18062862 DOI: 10.1016/s1472-6483(10)60532-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cryptorchidism has the potential to affect the health of the human male. Although it is often considered a mild malformation, it represents the best-characterized risk factor for reduced fertility and testicular cancer. The aetiology of cryptorchidism remains, for the most part, unknown and cryptorchidism itself might be considered a complex disease. This reflects the intricate mechanisms regulating testicular development and descent from intra-abdominal location into the bottom of the scrotum, involving different anatomical and hormonal factors. Major actors of testicular descent are the Leydig cell-derived hormones testosterone and insulin-like factor 3, even if other factors may play a role. Although considerable evidence exists in animals to support a genetic cause, the genetic contribution to human cryptorchidism is only recently being elucidated. Environmental factors might also contribute to the aetiology of cryptorchidism and its increased incidence in recent years. Mutations in the gene for insulin-like factor 3 and its receptor and in the androgen receptor gene explain a minority of cases of cryptorchidism, but research on genetic polymorphisms that may also influence susceptibility to endocrine disruptors is shedding light on this field.
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Affiliation(s)
- Alberto Ferlin
- University of Padova, Department of Histology, Microbiology and Medical Biotechnologies, Centre for Male Gamete Cryopreservation, Via Gabelli 63, 35121 Padova, Italy.
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Gurbuz N, Ozbay B, Aras B, Tasci AI. Do microdeletions in the AZF region of the Y chromosome accompany cryptorchidism in Turkish children? Int Urol Nephrol 2007; 40:577-81. [DOI: 10.1007/s11255-007-9318-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2007] [Accepted: 11/23/2007] [Indexed: 01/24/2023]
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16
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Virtanen H, Toppari J. Epidemiology and pathogenesis of cryptorchidism. Hum Reprod Update 2007; 14:49-58. [DOI: 10.1093/humupd/dmm027] [Citation(s) in RCA: 160] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Huynh J, Shenker NS, Nightingale S, Hutson JM. Signalling molecules: clues from development of the limb bud for cryptorchidism? Pediatr Surg Int 2007; 23:617-24. [PMID: 17429660 DOI: 10.1007/s00383-007-1907-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/27/2007] [Indexed: 11/26/2022]
Abstract
Recent studies of testicular descent suggest not only that the gubernaculum does not initially attach to the scrotum, but also that it must migrate from the groin. Two findings suggest that the gubernaculum may behave like an embryonic limb bud during this phase. First, the active growth centre is at the distal tip of the gubernaculum. Secondly, the gubernaculum is loose in the subcutaneous tissues beneath Scarpa's fascia. The free protrusion of the gubernaculum from the abdominal wall was so reminiscent of a developing embryonic limb bud, we thought that the biological controls of both processus may be similar. This review examines what is known about vertebrate limb bud development, and compares the mechanisms to what has recently been discovered in the gubernaculum. The hypothesis that both processes may be similar is initially consistent with the current facts, encouraging us to investigate this further experimentally.
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Affiliation(s)
- Jenny Huynh
- F Douglas Stephens Surgical Research Laboratory, Murdoch Children's Research Institute, Melbourne, VIC, Australia
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Abstract
In the last decade, significant progress in the knowledge and management of external genital anomalies has been achieved, including an improved understanding of epidemiology and pathophysiology of these anomalies, the identification of etiologic genetic defects, and significant improvements in surgical approaches that have decreased complications and improved cosmetic outcomes. We highlight the most clinically important advances of the commonly encountered external genital anomalies.
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Affiliation(s)
- Dawn L MacLellan
- Department of Urology, Dalhousie University Medical School, 5850-5890 University Avenue, PO Box 9700, Halifax, Nova Scotia, Canada B3K 6R8.
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Kaleva M, Toppari J. Cryptorchidism: an indicator of testicular dysgenesis? Cell Tissue Res 2005; 322:167-72. [PMID: 15965655 DOI: 10.1007/s00441-005-1143-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2004] [Accepted: 04/04/2005] [Indexed: 11/24/2022]
Abstract
Cryptorchidism is a common ailment of new-born boys, affecting 1-9% of full term boys at birth. Cryptorchidism has been associated with an increased risk of testicular cancer and reduced fertility. Aetiology of cryptorchidism remains obscure in most cases. Familial occurrence suggests a heritable susceptibility to cryptorchidism; however, seasonal variation in the incidence of cryptorchidism suggests that environmental factors also contribute. Testicular descent is characterised by androgen-dependent regression of cranial suspensory ligament and androgen + insulin-like hormone 3 (Ins l3)-dependent gubernacular outgrowth. Even though hormonal defects are rarely detected in patients, both hypo-and hypergonadotropic hormonal patterns have been associated with cryptorchidism. Moreover, cryptorchid boys have significantly reduced serum androgen bioactivity at 3 months of age when normal boys have a strong surge of reproductive hormones. Defects in Ins l3 action cause cryptorchidism in male mice, and over-expression in female mice causes ovarian descent. Defects in leucine-rich repeat-containing G-protein-coupled receptor 8/G-protein-coupled receptor affecting testis descent (LGR8/GREAT), the receptor for Ins l3, manifest the same phenotype as Ins l3 knockout mutants. Even though mutations found in Ins l3 and LGR8/GREAT genes are not a common cause of cryptorchidism in patients, it remains to be resolved whether low Ins l3 levels during development are associated with cryptorchidism. Cryptorchidism may reflect foetal testicular dysgenesis that may later manifest as subfertility or testicular cancer.
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Affiliation(s)
- Marko Kaleva
- Department of Physiology, University of Turku, 20520 Turku, Finland
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