1
|
Piñeyro-Ruiz C, Serrano H, Pérez-Brayfield MR, Jorge JC. New frontiers on the molecular underpinnings of hypospadias according to severity. Arab J Urol 2020; 18:257-266. [PMID: 33312738 PMCID: PMC7717703 DOI: 10.1080/2090598x.2020.1760589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Hypospadias, which is characterised by the displacement of the urethral meatus from its typical anatomical location in males, shows various degrees of severity. In this systematic review, we surveyed our current understanding of the genetics of isolated hypospadias in humans according to the severity of the condition. We found that sequencing and genotyping approaches were the preferred methods of study and that single nucleotide polymorphisms were the most common finding associated with hypospadias. Most genes fell into four gene-pathway categories related to androgens, oestrogens, growth factors, or transcription factors. Few hypospadias studies classify their findings by severity. Taken together, we argue that it is advantageous to take into consideration the severity of the condition in search of novel candidates in the aetiology of hypospadias. Abbreviations: AR: androgen receptor; ATF3: activating transcription factor 3; BMP4: bone morphogenetic protein 4; BMP7: bone morphogenetic protein 7; CYP17: steroid 17-alpha-hydroxylase/17,20 lyase; CYP1A1: cytochrome P450 1A1; CYP3A4: cytochrome P450 3A4; CNVs: copy number variants; DGKK: diacylglycerol kinase kappa; ESR1: oestrogen receptor 1; ESR2: oestrogen receptor 2; FGF8: fibroblast growth factor 8; FGF10: fibroblast growth factor 10; FGFR2: fibroblast growth factor receptor 2; HOXA4: homeobox protein Hox-A4; HOXB6: homeobox protein Hox-B6; HSD17B3: hydroxysteroid 17-beta dehydrogenase 3; MAMLD1: mastermind-like domain-containing protein 1; SF-1: splicing factor 1; SHH: sonic hedgehog; SNPs: single nucleotide polymorphisms; SOX9: SRY-box 9; SRD5A2: steroid 5 alpha-reductase 2; SRY: sex-determining region Y protein; STAR: steroidogenic acute regulatory protein; STARD3: StAR-related lipid transfer protein 3; STS: steryl-sulfatase; WT1: Wilms tumour protein; ZEB1: zinc finger oestrogen-box binding homeobox 1.
Collapse
Affiliation(s)
- Coriness Piñeyro-Ruiz
- Department of Anatomy and Neurobiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico, USA
| | - Horacio Serrano
- Department of Internal Medicine and Department of Biochemistry, University of Puerto Rico, San Juan, Puerto Rico, USA
| | - Marcos R Pérez-Brayfield
- Department of Surgery, Section of Urology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico, USA
| | - Juan Carlos Jorge
- Department of Anatomy and Neurobiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico, USA
| |
Collapse
|
2
|
Bouty A, Ayers KL, Pask A, Heloury Y, Sinclair AH. The Genetic and Environmental Factors Underlying Hypospadias. Sex Dev 2015; 9:239-259. [PMID: 26613581 DOI: 10.1159/000441988] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/24/2015] [Indexed: 12/22/2022] Open
Abstract
Hypospadias results from a failure of urethral closure in the male phallus and affects 1 in 200-300 boys. It is thought to be due to a combination of genetic and environmental factors. The development of the penis progresses in 2 stages: an initial hormone-independent phase and a secondary hormone-dependent phase. Here, we review the molecular pathways that contribute to each of these stages, drawing on studies from both human and mouse models. Hypospadias can occur when normal development of the phallus is disrupted, and we provide evidence that mutations in genes underlying this developmental process are causative. Finally, we discuss the environmental factors that may contribute to hypospadias and their potential immediate and transgenerational epigenetic impacts.
Collapse
Affiliation(s)
- Aurore Bouty
- Murdoch Children's Research Institute, Royal Children's Hospital, University of Melbourne, Melbourne, Vic., Australia.,Department of Surgery, Royal Children's Hospital, University of Melbourne, Melbourne, Vic., Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Vic., Australia
| | - Katie L Ayers
- Murdoch Children's Research Institute, Royal Children's Hospital, University of Melbourne, Melbourne, Vic., Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Vic., Australia
| | - Andrew Pask
- Department of Zoology, University of Melbourne, Melbourne, Vic., Australia
| | - Yves Heloury
- Murdoch Children's Research Institute, Royal Children's Hospital, University of Melbourne, Melbourne, Vic., Australia.,Department of Surgery, Royal Children's Hospital, University of Melbourne, Melbourne, Vic., Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Vic., Australia
| | - Andrew H Sinclair
- Murdoch Children's Research Institute, Royal Children's Hospital, University of Melbourne, Melbourne, Vic., Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Vic., Australia
| |
Collapse
|
3
|
George M, Schneuer FJ, Jamieson SE, Holland AJA. Genetic and environmental factors in the aetiology of hypospadias. Pediatr Surg Int 2015; 31:519-27. [PMID: 25742936 DOI: 10.1007/s00383-015-3686-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/17/2015] [Indexed: 02/07/2023]
Abstract
This article reviews the current evidence and knowledge of the aetiology of hypospadias. Hypospadias remains a fascinating anomaly of the male phallus. It may be an isolated occurrence or part of a syndrome or field defect. The increasing use of assisted reproductive techniques and hormonal manipulation during pregnancy may have been associated with an apparent rise in the incidence of hypospadias. Genetic studies and gene analysis have suggested some defects that could result in hypospadias. New light has also been thrown on environmental factors that could modulate candidate genes, causing altered development of the male external genitalia.
Collapse
Affiliation(s)
- Mathew George
- Douglas Cohen Department of Paediatric Surgery, The Children's Hospital at Westmead, Discipline of Paediatrics and Child Health, Sydney Medical School, The University of Sydney, Locked Bag 4001, Westmead, NSW, 2145, Australia
| | | | | | | |
Collapse
|
4
|
Baetens D, Mladenov W, Delle Chiaie B, Menten B, Desloovere A, Iotova V, Callewaert B, Van Laecke E, Hoebeke P, De Baere E, Cools M. Extensive clinical, hormonal and genetic screening in a large consecutive series of 46,XY neonates and infants with atypical sexual development. Orphanet J Rare Dis 2014; 9:209. [PMID: 25497574 PMCID: PMC4271496 DOI: 10.1186/s13023-014-0209-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 12/05/2014] [Indexed: 01/22/2023] Open
Abstract
Background One in 4500 children is born with ambiguous genitalia, milder phenotypes occur in one in 300 newborns. Conventional time-consuming hormonal and genetic work-up provides a genetic diagnosis in around 20-40% of 46,XY cases with ambiguous genitalia. All others remain without a definitive diagnosis. The investigation of milder cases, as suggested by recent reports remains controversial. Methods Integrated clinical, hormonal and genetic screening was performed in a sequential series of 46, XY children, sex-assigned male, who were referred to our pediatric endocrine service for atypical genitalia (2007–2013). Results A consecutive cohort of undervirilized 46,XY children with external masculinization score (EMS) 2–12, was extensively investigated. In four patients, a clinical diagnosis of Kallmann syndrome or Mowat-Wilson syndrome was made and genetically supported in 2/3 and 1/1 cases respectively. Hormonal data were suggestive of a (dihydro)testosterone biosynthesis disorder in four cases, however no HSD17B3 or SRD5A2 mutations were found. Array-CGH revealed a causal structural variation in 2/6 syndromic patients. In addition, three novel NR5A1 mutations were found in non-syndromic patients. Interestingly, one mutation was present in a fertile male, underlining the inter- and intrafamilial phenotypic variability of NR5A1-associated phenotypes. No AR, SRY or WT1 mutations were identified. Conclusion Overall, a genetic diagnosis could be established in 19% of non-syndromic and 33% of syndromic cases. There is no difference in diagnostic yield between patients with more or less pronounced phenotypes, as expressed by the external masculinisation score (EMS). The clinical utility of array-CGH is high in syndromic cases. Finally, a sequential gene-by-gene approach is time-consuming, expensive and inefficient. Given the low yield and high expense of Sanger sequencing, we anticipate that massively parallel sequencing of gene panels and whole exome sequencing hold promise for genetic diagnosis of 46,XY DSD boys with an undervirilized phenotype. Electronic supplementary material The online version of this article (doi:10.1186/s13023-014-0209-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Dorien Baetens
- Center for Medical Genetics, Ghent University Hospital and Ghent University, Ghent, Belgium.
| | - Wilhelm Mladenov
- Department of Pediatric Endocrinology, Ghent University Hospital and Ghent University, Building 3K12D, De Pintelaan 185, 9000, Ghent, Belgium. .,Department of Pediatrics and Medical Genetics, Medical University of Varna, University Hospital "Sveta Marina", Varna, Bulgaria.
| | - Barbara Delle Chiaie
- Center for Medical Genetics, Ghent University Hospital and Ghent University, Ghent, Belgium.
| | - Björn Menten
- Center for Medical Genetics, Ghent University Hospital and Ghent University, Ghent, Belgium.
| | - An Desloovere
- Department of Pediatric Endocrinology, Ghent University Hospital and Ghent University, Building 3K12D, De Pintelaan 185, 9000, Ghent, Belgium.
| | - Violeta Iotova
- Department of Pediatrics and Medical Genetics, Medical University of Varna, University Hospital "Sveta Marina", Varna, Bulgaria.
| | - Bert Callewaert
- Center for Medical Genetics, Ghent University Hospital and Ghent University, Ghent, Belgium.
| | - Erik Van Laecke
- Department of Pediatric Urology, Ghent University Hospital and Ghent University, Ghent, Belgium.
| | - Piet Hoebeke
- Department of Pediatric Urology, Ghent University Hospital and Ghent University, Ghent, Belgium.
| | - Elfride De Baere
- Center for Medical Genetics, Ghent University Hospital and Ghent University, Ghent, Belgium.
| | - Martine Cools
- Department of Pediatric Endocrinology, Ghent University Hospital and Ghent University, Building 3K12D, De Pintelaan 185, 9000, Ghent, Belgium.
| |
Collapse
|
5
|
Rasouly HM, Lu W. Lower urinary tract development and disease. WILEY INTERDISCIPLINARY REVIEWS. SYSTEMS BIOLOGY AND MEDICINE 2013; 5:307-42. [PMID: 23408557 PMCID: PMC3627353 DOI: 10.1002/wsbm.1212] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Congenital anomalies of the lower urinary tract (CALUT) are a family of birth defects of the ureter, the bladder, and the urethra. CALUT includes ureteral anomaliesc such as congenital abnormalities of the ureteropelvic junction (UPJ) and ureterovesical junction (UVJ), and birth defects of the bladder and the urethra such as bladder-exstrophy-epispadias complex (BEEC), prune belly syndrome (PBS), and posterior urethral valves (PUVs). CALUT is one of the most common birth defects and is often associated with antenatal hydronephrosis, vesicoureteral reflux (VUR), urinary tract obstruction, urinary tract infections (UTI), chronic kidney disease, and renal failure in children. Here, we discuss the current genetic and molecular knowledge about lower urinary tract development and genetic basis of CALUT in both human and mouse models. We provide an overview of the developmental processes leading to the formation of the ureter, the bladder, and the urethra, and different genes and signaling pathways controlling these developmental processes. Human genetic disorders that affect the ureter, the bladder and the urethra and associated gene mutations are also presented. As we are entering the postgenomic era of personalized medicine, information in this article may provide useful interpretation for the genetic and genomic test results collected from patients with lower urinary tract birth defects. With evidence-based interpretations, clinicians may provide more effective personalized therapies to patients and genetic counseling for their families.
Collapse
Affiliation(s)
- Hila Milo Rasouly
- Renal Section, Department of Medicine, Boston University Medical Center, Boston, MA 02118, USA
| | - Weining Lu
- Renal Section, Department of Medicine, Boston University Medical Center, Boston, MA 02118, USA
| |
Collapse
|
6
|
Adamovic T, Nordenskjöld A. The CAG repeat polymorphism in the androgen receptor gene modifies the risk for hypospadias in Caucasians. BMC MEDICAL GENETICS 2012; 13:109. [PMID: 23167717 PMCID: PMC3560208 DOI: 10.1186/1471-2350-13-109] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Accepted: 10/31/2012] [Indexed: 11/29/2022]
Abstract
Background Hypospadias is a birth defect of the urethra in males, and a milder form of 46,XY disorder of sexual development (DSD). The disease is characterized by a ventrally placed urinary opening due to a premature fetal arrest of the urethra development. Moreover, the Androgen receptor (AR) gene has an essential role in the hormone-dependent stage of sexual development. In addition, longer AR polyglutamine repeat lengths encoded by CAG repeats are associated with lower transcriptional activity in vitro. In the present study, we aimed at investigating the role of the CAG repeat length in the AR gene in hypospadias cases as compared to the controls. Our study included 211 hypospadias and 208 controls of Caucasian origin. Methods We amplified the CAG repeat region with PCR, and calculated the difference in the mean CAG repeat length between the hypospadias and control group using the T-test for independent groups. Results We detected a significant increase of the CAG repeat length in the hypospadias cases when compared to the controls (contrast estimate: 2.29, 95% Confidence Interval (1.73-2.84); p-value: 0.001). In addition, the odds ratios between the hypospadias and controls revealed that the hypospadias cases are two to 3 times as likely to have longer CAG repeats than a shorter length for each repeat length investigated. Conclusions We have investigated the largest number of hypospadias cases with regards to the CAG repeat length, and we provide evidence that a higher number of the CAG repeat sequence in the AR gene have a clear effect on the risk of hypospadias in Caucasians.
Collapse
Affiliation(s)
- Tatjana Adamovic
- Department of Women's and Children's Health and Center of Molecular Medicine-CMM, Karolinska Institutet, SE-171 76 Stockholm, Sweden.
| | | |
Collapse
|
7
|
Human balanced translocation and mouse gene inactivation implicate Basonuclin 2 in distal urethral development. Eur J Hum Genet 2011; 19:540-6. [PMID: 21368915 DOI: 10.1038/ejhg.2010.245] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
We studied a man with distal hypospadias, partial anomalous pulmonary venous return, mild limb-length inequality and a balanced translocation involving chromosomes 9 and 13. To gain insight into the etiology of his birth defects, we mapped the translocation breakpoints by high-resolution comparative genomic hybridization (CGH), using chromosome 9- and 13-specific tiling arrays to analyze genetic material from a spontaneously aborted fetus with unbalanced segregation of the translocation. The chromosome 13 breakpoint was ∼400 kb away from the nearest gene, but the chromosome 9 breakpoint fell within an intron of Basonuclin 2 (BNC2), a gene that encodes an evolutionarily conserved nuclear zinc-finger protein. The BNC2/Bnc2 gene is abundantly expressed in developing mouse and human periurethral tissues. In all, 6 of 48 unrelated subjects with distal hypospadias had nine novel nonsynonymous substitutions in BNC2, five of which were computationally predicted to be deleterious. In comparison, two of 23 controls with normal penile urethra morphology, each had a novel nonsynonymous substitution in BNC2, one of which was predicted to be deleterious. Bnc2(-/-) mice of both sexes displayed a high frequency of distal urethral defects; heterozygotes showed similar defects with reduced penetrance. The association of BNC2 disruption with distal urethral defects and the gene's expression pattern indicate that it functions in urethral development.
Collapse
|
8
|
Abstract
Hypospadias is the second most common genital anomaly in children. The etiology of hypospadias remains unknown in the overwhelming majority of patients. Herein, I review the etiology of hypospadias and propose that hypospadias can be explained by a two-hit hypothesis: genetic susceptibility plus environmental exposure to endocrine disruptors. The strategy to prevent hypospadias should be focused on (1) identifying genetic susceptibility prior to pregnancy and (2) identifying and eliminating exposure to potential toxic endocrine disruptors that effect urethral development.
Collapse
Affiliation(s)
- Laurence S Baskin
- UCSF Children's Hospital, Department of Urology and Pediatrics, 400 Parnassus Avenue, A640, San Francisco, CA 94143, USA.
| |
Collapse
|
9
|
Beleza-Meireles A, Barbaro M, Wedell A, Töhönen V, Nordenskjöld A. Studies of a co-chaperone of the androgen receptor, FKBP52, as candidate for hypospadias. Reprod Biol Endocrinol 2007; 5:8. [PMID: 17343741 PMCID: PMC1821330 DOI: 10.1186/1477-7827-5-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Accepted: 03/07/2007] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Hypospadias is a common inborn error of the male urethral development, for which the aetiology is still elusive. Polymorphic variants in genes involved in the masculinisation of male genitalia, such as the androgen receptor, have been associated with some cases of hypospadias. Co-regulators of the androgen receptor start being acknowledged as possible candidates for hormone-resistance instances, which could account for hypospadias. One such molecule, the protein FKBP52, coded by the FKBP4 gene, has an important physiological role in up-regulating androgen receptor activity, an essential step in the development of the male external genitalia. The presence of hypospadias in mice lacking fkbp52 encouraged us to study the sequence and the expression of FKBP4 in boys with isolated hypospadias. PATIENTS AND METHODS The expression of FKBP52 in the genital skin of boys with hypospadias and in healthy controls was tested by immunohistochemistry. Mutation screening in the FKBF4 gene was performed in ninety-one boys with non syndromic hypospadias. Additionally, two polymorphisms were typed in a larger cohort. RESULTS Immunohistochemistry shows epithelial expression of FKBP52 in the epidermis of the penile skin. No apparent difference in the FKBP52 expression was detected in healthy controls, mild or severe hypospadias patients. No sequence variants in the FKBP4 gene have implicated in hypospadias in our study. CONCLUSION FKBP52 is likely to play a role in growth and development of the male genitalia, since it is expressed in the genital skin of prepubertal boys; however alterations in the sequence and in the expression of the FKBP4 gene are not a common cause of non-syndromic hypospadias.
Collapse
Affiliation(s)
- Ana Beleza-Meireles
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Michela Barbaro
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Anna Wedell
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Virpi Töhönen
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Agneta Nordenskjöld
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
- Department of Women and Child Health, Astrid Lindgren Children Hospital, Karolinska University Hospital, Stockholm, Sweden
| |
Collapse
|
10
|
Miyamoto J, Asanuma H, Nakai H, Hasegawa T, Nawata H, Hasegawa Y. Mutational Analysis of Androgen Receptor (AR) Gene in 46,XY Patients with Ambiguous Genitalia and Normal Testosterone Secretion: Endocrinological Characteristics of Three Patients with AR Gene Mutations. Clin Pediatr Endocrinol 2006; 15:151-62. [PMID: 24790336 PMCID: PMC4004867 DOI: 10.1297/cpe.15.151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Accepted: 08/02/2006] [Indexed: 12/05/2022] Open
Abstract
The prevalence of abnormalities in androgen receptor gene (AR) among patients with
ambiguous genitalia is unknown. Moreover, endocrinological data from prepubertal patients
with AR mutation are very limited. Thus, the aim of this study was to examine the
prevalence of abnormalities in AR among patients with both ambiguous genitalia, which was
defined as a combination of two or more genital abnormalities (i.e. hypospadias,
microphallus (penile length < 25 mm), hypoplastic scrotum, bifid scrotum, undescended
testis) in this study, and normal to elevated T levels. We also compared the
endocrinological data of prepubertal patients with AR mutation and ambiguous genitalia
with that of those without the AR mutation. We screened 26 Japanese prepubertal 46,XY
patients (five from three families were included) with both ambiguous genitalia and normal
to elevated T levels. Mutations in AR were found in three (two of the three were related).
Among the 23 patients without mutation in AR, the steroid 5-alpha-reductase 2 gene
(SRD5A2) was also examined in eight patients with elevated T/dehydrotestosterone ratio
after the hCG (>10) or with undervirilized family members. No mutation in SRD5A2 was
found. Characteristics of the three patients with mutation in AR were compared with the 23
patients without mutation. In two patients, basal T levels (0.3, 0.2 ng/ml) and peak T
levels after the hCG tests (8.3, 8.5 ng/ml) tended to be higher, and the peak LH/ peak FSH
ratios after the GnRH tests (4.6, 4.0) were higher than in patients without mutation, at
the ages of 1 yr and 9 mo and 3 yr and 8 mo, respectively. In conclusion, an abnormality
in either AR or SRD5A2 was not common among patients with ambiguous genitalia and normal
testosterone secretion. Elevated peak LH/peak FSH ratio (≥4) after the GnRH test in
addition to detectable basal T levels and elevated peak T levels after the hCG test may
infer AR abnormality in prepubertal patients with ambiguous genitalia at the age of one
and over, although further study is needed, because our data were limited.
Collapse
Affiliation(s)
- Junko Miyamoto
- Endocrinology and Metabolism unit, Tokyo Metropolitan Kiyose Children's Hospital, Tokyo, Japan
| | - Hiroshi Asanuma
- Urology Unit, Tokyo Metropolitan Kiyose Children's Hospital, Tokyo, Japan
| | - Hideo Nakai
- Urology Unit, Dokkyo University School of Medicine, Saitama, Japan
| | - Tomonobu Hasegawa
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
| | - Hajime Nawata
- Department of Medicine and Bioregulatory Science (Third Department of Internal Medicine), Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yukihiro Hasegawa
- Endocrinology and Metabolism unit, Tokyo Metropolitan Kiyose Children's Hospital, Tokyo, Japan
| |
Collapse
|
11
|
Mansouri MR, Carlsson B, Davey E, Nordenskjöld A, Wester T, Annerén G, Läckgren G, Dahl N. Molecular genetic analysis of a de novo balanced translocation t(6;17)(p21.31;q11.2) associated with hypospadias and anorectal malformation. Hum Genet 2006; 119:162-8. [PMID: 16395596 DOI: 10.1007/s00439-005-0122-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2005] [Accepted: 12/09/2005] [Indexed: 10/25/2022]
Abstract
We report a young boy with penoscrotal hypospadias, anal atresia (AA) with a recto-urethral fistula, a hypoplastic kidney and a balanced translocation t(6;17)(p21.31;q11.2). Physical mapping of the breakpoints localized the chromosome 6 breakpoint within an intron of the gene lipoma HMGIC fusion partner-like 5 (LHFPL5) whereas the chromosome 17 breakpoint was mapped to the first intron of the 182-FIP gene encoding the Fragile X Mental Retardation Protein Interacting Protein. Sequence analysis across the breakpoints revealed an almost perfectly balanced translocation with a 2 bp deletion on the derivative chromosome 6 and a 7 bp duplication on the derivative chromosome 17. We identified a fusion transcript consisting of the first exon of 182-FIP and the last exon of LHFPL5 in patient-derived cells. Quantitative expression analysis of the genes flanking the breakpoints, revealed increased transcript levels for SFRS protein kinase 1 (SRPK1) and TAO kinase 1 (TAOK1) which suggests a positional effect due to the translocation. We hypothesize that the urogenital and anorectal malformations in the patient result from one or several mechanisms including disruption of the genes 182-FIP and LHFPL5, altered expression of the genes flanking the translocation breakpoints and, a gain of function mechanism mediated by the 182-FIP-LHFPL5 fusion transcript.
Collapse
Affiliation(s)
- Mahmoud Reza Mansouri
- Department of genetics and pathology, Section of Clinical Genetics The Rudbeck laboratory, Uppsala University, 751 85 Uppsala, Sweden
| | | | | | | | | | | | | | | |
Collapse
|