The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Ken Mcelreavey - One of the best experts on this subject based on the ideXlab platform.
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the Y Chromosome and male fertilitY and infertilitY
International Journal of Andrology, 2003Co-Authors: Csilla Krausz, Gianni Forti, Ken McelreaveyAbstract:Since 1995, thanks to a large number of studies, Y Chromosome Microdeletion screening has become part of the routine diagnostic work-up of severe male factor infertilitY. ManY initial contradictorY issues such as variabilitY in deletion frequencY, markers to be tested, presence of deletions in 'fertile' men, and genotYpe-phenotYpe correlation has been resolved. Past and present unresolved issues are discussed in this review.
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double blind Y Chromosome Microdeletion analYsis in men with known sperm parameters and reproductive hormone profiles Microdeletions are specific for spermatogenic failure
The Journal of Clinical Endocrinology and Metabolism, 2001Co-Authors: Csilla Krausz, Ken Mcelreavey, Lluis Quintanamurci, Ewa Rajpertde Meyts, Lone Frydelundlarsen, Niels E SkakkebaekAbstract:Y Chromosome Microdeletions have been reported as a possible genetic factor of male infertilitY. Despite a large number of studies in this subject, there is still considerable debate and confusion surrounding the role of Y Chromosome Microdeletions in male infertilitY. This has been further compounded bY observations of Y Microdeletions in fertile males. The aim of the present studY was to evaluate: 1) the incidence of Y Microdeletions in control male population and infertile males, where complete semen and hormonal analYsis was available to define whether Y Microdeletions are specific for spermatogenic failure or if theY can be found also in normospermic men; and 2) whether the suboptimal semen qualitY reported in Denmark is associated with a higher incidence of Y Microdeletions in respect to other populations. Double-blind molecular studY of deletions was performed in 138 consecutive patients seeking intracYtoplasmic sperm injection treatment, 100 men of known fertilitY, and 107 Young militarY conscripts from the general Danish population. Microdeletions or gene-specific deletions were not detected in normospermic subjects or in subfertile men with a sperm count of more than 1 x 10(6)/mL. Deletions of the Azoospermia factor (AZF)c region were detected in 17% of individuals with idiopathic azoo/crYptozoospermia and in 7% of individuals with nonidiopathic azoo/crYptozoospermia. The data indicate that: 1) the composition of the studY population is the major factor in determining deletion frequencY; 2) Y Chromosome Microdeletions are specificallY associated with severe spermatogenic failure; therefore, the protocol described here is reliable for the routine clinical workup of severe male factor infertilitY; and 3) the frequencY of Yq Microdeletions in the Danish population is similar to that from other countries and argues against the involvement of Microdeletions in the relativelY low sperm count of the Danish population.
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prognostic value of Y deletion analYsis what is the clinical prognostic value of Y Chromosome Microdeletion analYsis
Human Reproduction, 2000Co-Authors: Csilla Krausz, Lluis Quintanamurci, Ken McelreaveyAbstract:Abstract In manY centres, Y Chromosome deletion analYsis is still not performed routinelY and if so, the results are used for genetic counselling but are not considered as having a useful prognostic value. The tYpe of deletion (AZFa, b or c) has been proposed as a potential prognostic factor for sperm retrieval in men undergoing TESE. AZFc deletions and partial AZFb deletions are associated with sperm retrieval in approximatelY 50% of cases while in the case of a patient with complete AZFb deletion the probabilitY of finding mature spermatozoa is virtuallY nil. Therefore the extent and position of a Y Microdeletion is important (complete or partial). The prognostic value of Y Chromosome deletion analYsis in cases of oligozoospermia is important when one considers the progressive decrease of sperm number over time in men with AZFc deletions. CrYo-conservation of spermatozoa in these cases could avoid invasive techniques, such as TESE/ICSI, in the future. Male offspring that are conceived bY ICSI or IVF techniques from father with oligozoospermia or azoospermia would also benefit from knowledge of their Y status, since the identification of the genetic defect will render future medical or surgical therapies unnecessarY. Y Microdeletion screening is therefore important, not onlY to define the aetiologY of spermatogenic failure, but also because it gives precious information for a more appropriate clinical management of both the infertile male and his future male child.
Csilla Krausz - One of the best experts on this subject based on the ideXlab platform.
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the Y Chromosome and male fertilitY and infertilitY
International Journal of Andrology, 2003Co-Authors: Csilla Krausz, Gianni Forti, Ken McelreaveyAbstract:Since 1995, thanks to a large number of studies, Y Chromosome Microdeletion screening has become part of the routine diagnostic work-up of severe male factor infertilitY. ManY initial contradictorY issues such as variabilitY in deletion frequencY, markers to be tested, presence of deletions in 'fertile' men, and genotYpe-phenotYpe correlation has been resolved. Past and present unresolved issues are discussed in this review.
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double blind Y Chromosome Microdeletion analYsis in men with known sperm parameters and reproductive hormone profiles Microdeletions are specific for spermatogenic failure
The Journal of Clinical Endocrinology and Metabolism, 2001Co-Authors: Csilla Krausz, Ken Mcelreavey, Lluis Quintanamurci, Ewa Rajpertde Meyts, Lone Frydelundlarsen, Niels E SkakkebaekAbstract:Y Chromosome Microdeletions have been reported as a possible genetic factor of male infertilitY. Despite a large number of studies in this subject, there is still considerable debate and confusion surrounding the role of Y Chromosome Microdeletions in male infertilitY. This has been further compounded bY observations of Y Microdeletions in fertile males. The aim of the present studY was to evaluate: 1) the incidence of Y Microdeletions in control male population and infertile males, where complete semen and hormonal analYsis was available to define whether Y Microdeletions are specific for spermatogenic failure or if theY can be found also in normospermic men; and 2) whether the suboptimal semen qualitY reported in Denmark is associated with a higher incidence of Y Microdeletions in respect to other populations. Double-blind molecular studY of deletions was performed in 138 consecutive patients seeking intracYtoplasmic sperm injection treatment, 100 men of known fertilitY, and 107 Young militarY conscripts from the general Danish population. Microdeletions or gene-specific deletions were not detected in normospermic subjects or in subfertile men with a sperm count of more than 1 x 10(6)/mL. Deletions of the Azoospermia factor (AZF)c region were detected in 17% of individuals with idiopathic azoo/crYptozoospermia and in 7% of individuals with nonidiopathic azoo/crYptozoospermia. The data indicate that: 1) the composition of the studY population is the major factor in determining deletion frequencY; 2) Y Chromosome Microdeletions are specificallY associated with severe spermatogenic failure; therefore, the protocol described here is reliable for the routine clinical workup of severe male factor infertilitY; and 3) the frequencY of Yq Microdeletions in the Danish population is similar to that from other countries and argues against the involvement of Microdeletions in the relativelY low sperm count of the Danish population.
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prognostic value of Y deletion analYsis what is the clinical prognostic value of Y Chromosome Microdeletion analYsis
Human Reproduction, 2000Co-Authors: Csilla Krausz, Lluis Quintanamurci, Ken McelreaveyAbstract:Abstract In manY centres, Y Chromosome deletion analYsis is still not performed routinelY and if so, the results are used for genetic counselling but are not considered as having a useful prognostic value. The tYpe of deletion (AZFa, b or c) has been proposed as a potential prognostic factor for sperm retrieval in men undergoing TESE. AZFc deletions and partial AZFb deletions are associated with sperm retrieval in approximatelY 50% of cases while in the case of a patient with complete AZFb deletion the probabilitY of finding mature spermatozoa is virtuallY nil. Therefore the extent and position of a Y Microdeletion is important (complete or partial). The prognostic value of Y Chromosome deletion analYsis in cases of oligozoospermia is important when one considers the progressive decrease of sperm number over time in men with AZFc deletions. CrYo-conservation of spermatozoa in these cases could avoid invasive techniques, such as TESE/ICSI, in the future. Male offspring that are conceived bY ICSI or IVF techniques from father with oligozoospermia or azoospermia would also benefit from knowledge of their Y status, since the identification of the genetic defect will render future medical or surgical therapies unnecessarY. Y Microdeletion screening is therefore important, not onlY to define the aetiologY of spermatogenic failure, but also because it gives precious information for a more appropriate clinical management of both the infertile male and his future male child.
Kiran Singh - One of the best experts on this subject based on the ideXlab platform.
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Microdeletion of Y Chromosome as a cause of recurrent pregnancY loss
Journal of Human Reproductive Sciences, 2015Co-Authors: Shubhra Agarwal, A K Khanna, Arjit Agarwal, Kiran SinghAbstract:CONTEXT: In majoritY of couples experiencing recurrent pregnancY loss (RPL), etiologY is still unknown. Two genetic factors have been suggested to underlie miscarriage in a subset of patients, namelY skewed X Chromosome inactivation in females and Y Chromosome Microdeletions in their partners. In males, Microdeletions of the Y Chromosome are known to cause spermatogenetic failure and male infertilitY. AIMS: The aim of the studY was to find out the role of Y Chromosome Microdeletion in male partners of couples experiencing RPL. SETTINGS AND DESIGN: UniversitY hospital and genetic laboratorY. Prospective case–control studY. SUBJECTS AND METHODS: 59 couples with a historY of RPL and 20 fertile controls (FC) with no miscarriage were included in the studY. The studY subjects were divided into male partners of RPL couples with abnormal semen parameters (AS) (n = 8), and couples with normal semen parameters (NS) (n = 51). Fertile controls with normal semen parameters were (FC) (n = 20). Y Chromosome Microdeletion was performed on 40 male partners of RPL and 20 FC. STATISTICAL ANALYSIS USED: Chi-square test. P <0.05 were considered statisticallY significant. RESULTS: 13 of the 40 RPL cases showed deletion in three azoospermia factor loci on the long arm of Y Chromosome. The P value was significant with Y Chromosome Microdeletion in RPL cases as compared to 20 FC where no Y Chromosome Microdeletion was present. CONCLUSIONS: Y Chromosome Microdeletion maY be an important hidden cause of recurrent pregnancY miscarriage and can be offered to couples with the undiagnosed cause of miscarriage.
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idiopathic cases of male infertilitY from a region in india show low incidence of Y Chromosome Microdeletion
Journal of Biosciences, 2003Co-Authors: R Ambasudhan, Kiran Singh, J K Agarwal, Subodh Kumar Singh, A K Khanna, R K Sah, Indra Singh, Rajiva RamanAbstract:Chromosomal and Y-chromosomal Microdeletion analYsis has been done in cases of idiopathic infertilitY with the objective of evaluating the frequencY of chromosomal and molecular anomalY as the causal factor of infertilitY. Barring a few cases of Klinefelter sYndrome (XXY or XY/XXY mosaics), no chromosomal anomalY was encountered. Y-Microdeletion was analYsed bY PCR-screening of STSs from different regions of the AZF (AZFa, AZFb, AZFc) on the long arm of the Y, as well as bY using DNA probes of the genes RBM, DAZ (Yq), DAZLA (an autosomal homologue of DAZ) and SRY (Yp; sex determining gene). Out of 177 cases examined, 9 (azoospermia -8 and oligoasthenospermia -1) showed partial deletion of AZF. The size of deletion varied among patients but AZFc was either totallY or partiallY removed in all of them. In contrast, no deletion was detected in AZFa. Testis biopsY done on a limited number of cases (50) showed diverse stages of spermatogenic arrest with no specific correlation with the genotYpe. The frequencY of Y-Chromosome Microdeletion in our samples (∼ 5%) is much lower than the frequencY (∼ 10%) reported globallY and the two previous reports from India. We contend that the frequencY maY be affected bY population structures in different geographical regions.
Ferda E Percin - One of the best experts on this subject based on the ideXlab platform.
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Y Chromosome azoospermia factor region Microdeletions and recurrent pregnancY loss
American Journal of Obstetrics and Gynecology, 2008Co-Authors: Abdullah Karaer, Kadri Karaer, Gulnur Ozaksit, Serdar Ceylaner, Ferda E PercinAbstract:Objective This studY was undertaken to determine the prevalence of Y-Chromosome Microdeletions in couples with recurrent pregnancY loss (RPL) as compared with fertile couples. StudY Design FortY-three men from couples with recurrent pregnancY loss, and 43 men from couples with a live birth and no historY of miscarriages were recruited from Zekai Tahir Burak Woman Health, Education and Research Hospital. The DNA was tested for the presence of 4 sequence tagged sites (STSs) spanning 4 AZF regions: DYS220 (AZFb), DYS235, DYS236, and DYS237 (AZFd). Results Seven (7) of the 43 men (16%) from couples with recurrent pregnancY loss had Microdeletions in 1 or more of the 4 segments studied, whereas none of the fertile men had anY Microdeletions (P Conclusion The prevalence of the Y Chromosome Microdeletion in AZF region was much higher in men from couples with recurrent pregnancY loss than men in fertile couples. This studY showed that Y Chromosome Microdeletion in AZF region maY be a possible etiologic factor of recurrent pregnancY loss.
A K Khanna - One of the best experts on this subject based on the ideXlab platform.
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Microdeletion of Y Chromosome as a cause of recurrent pregnancY loss
Journal of Human Reproductive Sciences, 2015Co-Authors: Shubhra Agarwal, A K Khanna, Arjit Agarwal, Kiran SinghAbstract:CONTEXT: In majoritY of couples experiencing recurrent pregnancY loss (RPL), etiologY is still unknown. Two genetic factors have been suggested to underlie miscarriage in a subset of patients, namelY skewed X Chromosome inactivation in females and Y Chromosome Microdeletions in their partners. In males, Microdeletions of the Y Chromosome are known to cause spermatogenetic failure and male infertilitY. AIMS: The aim of the studY was to find out the role of Y Chromosome Microdeletion in male partners of couples experiencing RPL. SETTINGS AND DESIGN: UniversitY hospital and genetic laboratorY. Prospective case–control studY. SUBJECTS AND METHODS: 59 couples with a historY of RPL and 20 fertile controls (FC) with no miscarriage were included in the studY. The studY subjects were divided into male partners of RPL couples with abnormal semen parameters (AS) (n = 8), and couples with normal semen parameters (NS) (n = 51). Fertile controls with normal semen parameters were (FC) (n = 20). Y Chromosome Microdeletion was performed on 40 male partners of RPL and 20 FC. STATISTICAL ANALYSIS USED: Chi-square test. P <0.05 were considered statisticallY significant. RESULTS: 13 of the 40 RPL cases showed deletion in three azoospermia factor loci on the long arm of Y Chromosome. The P value was significant with Y Chromosome Microdeletion in RPL cases as compared to 20 FC where no Y Chromosome Microdeletion was present. CONCLUSIONS: Y Chromosome Microdeletion maY be an important hidden cause of recurrent pregnancY miscarriage and can be offered to couples with the undiagnosed cause of miscarriage.
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idiopathic cases of male infertilitY from a region in india show low incidence of Y Chromosome Microdeletion
Journal of Biosciences, 2003Co-Authors: R Ambasudhan, Kiran Singh, J K Agarwal, Subodh Kumar Singh, A K Khanna, R K Sah, Indra Singh, Rajiva RamanAbstract:Chromosomal and Y-chromosomal Microdeletion analYsis has been done in cases of idiopathic infertilitY with the objective of evaluating the frequencY of chromosomal and molecular anomalY as the causal factor of infertilitY. Barring a few cases of Klinefelter sYndrome (XXY or XY/XXY mosaics), no chromosomal anomalY was encountered. Y-Microdeletion was analYsed bY PCR-screening of STSs from different regions of the AZF (AZFa, AZFb, AZFc) on the long arm of the Y, as well as bY using DNA probes of the genes RBM, DAZ (Yq), DAZLA (an autosomal homologue of DAZ) and SRY (Yp; sex determining gene). Out of 177 cases examined, 9 (azoospermia -8 and oligoasthenospermia -1) showed partial deletion of AZF. The size of deletion varied among patients but AZFc was either totallY or partiallY removed in all of them. In contrast, no deletion was detected in AZFa. Testis biopsY done on a limited number of cases (50) showed diverse stages of spermatogenic arrest with no specific correlation with the genotYpe. The frequencY of Y-Chromosome Microdeletion in our samples (∼ 5%) is much lower than the frequencY (∼ 10%) reported globallY and the two previous reports from India. We contend that the frequencY maY be affected bY population structures in different geographical regions.
