AZFb microdeletions and oligozoospermia—which mechanisms?

Soares, Ana Rita; Costa, Paula Cristina Pereira da; Silva, Joaquina; Sousa, Mário; Barros, Alberto; Fernandes, Susana

doi:10.1016/j.fertnstert.2012.01.099

Cited by 47 publications

(42 citation statements)

References 34 publications

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“…One case had AZFb + DAZ microdeletions and severe oligozoospermia (one cycle TESE, without pregnancy, followed by two cycles with cryopreserved sperm without pregnancy, and one cycle with ejaculated sperm without pregnancy). This patient had a normal karyotype and presented a P5/proximal P1 microdeletion 16. Two patients had partial AZFb + DAZ microdeletions and severe oligozoospermia: one case performed two cycles with ejaculated sperm, without fertilization, has a normal karyotype and a IR4/distal P2 microdeletion;16 and the other case performed one cycle TESE, with abortion of a singleton pregnancy, has a normal karyotype and a IR4/proximal P1 microdeletion 16.…”

Section: Resultsmentioning

confidence: 95%

“…This patient had a normal karyotype and presented a P5/proximal P1 microdeletion 16. Two patients had partial AZFb + DAZ microdeletions and severe oligozoospermia: one case performed two cycles with ejaculated sperm, without fertilization, has a normal karyotype and a IR4/distal P2 microdeletion;16 and the other case performed one cycle TESE, with abortion of a singleton pregnancy, has a normal karyotype and a IR4/proximal P1 microdeletion 16. Of the 22 patients with AZFbc microdeletions, 1 had severe oligozoospermia (two cycles with ejaculated sperm, one cycle without pregnancy, and one cycle with abortion of a triplet pregnancy).…”

Section: Resultsmentioning

confidence: 98%

“…The markers used were combined in four different multiplex-PCR, and the results were checked by capillary electrophoresis (QIAxcel, Qiagen, Hilden, Germany). For the optimal detection of AZF deletions, we followed the published indications for AZFa,1112131519 AZFb, and AZFc 14161922. Besides the indicated STS markers, we also performed additional STS markers for spanning all AZF regions and SRY:11121314151620…”

Section: Methodsmentioning

confidence: 99%

“…Distinct histopathology phenotypes were correlated with the site of the microdeletion, varying from complete absence of germ cells (Sertoli Cell-Only Syndrome, SCOS) in patients with AZFa microdeletions, maturation arrest at meiosis (MA) in cases with AZFb microdeletions, to hypospermatogenesis (HP) in patients with AZFc microdeletions 59111213141516. However, individual variation on the extent of microdeletions has led to the observation of incomplete microdeletions which enable the existence of spermatogenesis foci in SCOS and MA and thus successful testicular sperm retrieval 17181920.…”

Section: Introductionmentioning

confidence: 99%

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Y-chromosome microdeletions in nonobstructive azoospermia and severe oligozoospermia

et al. 2017

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The aim of the present work was to present the outcomes of the patients with Y-chromosome microdeletions treated by intracytoplasmic sperm injection (ICSI), either using fresh (TESE) or frozen-thawed (TESE-C) testicular sperm and ejaculated sperm (EJAC). The originality of this work resides in the comparisons between the different types of Y-microdeletions (AZFa, AZFb, and AZFc) and treatments, with detailed demographic, stimulation, embryological, clinical, and newborn (NB) outcomes. Of 125 patients with Y-microdeletions, 33 patients presented severe oligozoospermia (18 performed ICSI with ejaculated sperm) and 92 secretory azoospermia (65 went for TESE with 40 having successful sperm retrieval and performed ICSI). There were 51 TESE treatment cycles and 43 TESE-C treatment cycles, with a birth of 19 NB (2 in AZFa/TESE-C, 12 in AZFc/TESE, and 5 in AZFc/TESE-C). Of the 29 EJAC cycles, there was a birth of 8 NB (in AZFc). In TESE and EJAC cycles, there were no significant differences in embryological and clinical parameters. In TESE-C cycles, there was a significant lower oocyte maturity rate, embryo cleavage rate and mean number of embryos transferred in AZFb, and a higher mean number of oocytes and lower fertilization rate in AZFc. In conclusion, although patients with AZFc microdeletions presented a high testicular sperm recovery rate and acceptable clinical outcomes, cases with AZFa and AZFb microdeletions presented a poor prognosis. Due to the reported heredity of microdeletions, patients should be informed about the infertile consequences on NB and the possibility of using preimplantation genetic diagnosis for female sex selection.

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Section: Resultsmentioning

confidence: 95%

Section: Resultsmentioning

confidence: 98%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Y-chromosome microdeletions in nonobstructive azoospermia and severe oligozoospermia

et al. 2017

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“…More partial AZFb deletions associated with variable testicular histologies but not meiotic arrest and with distal breakpoints concentrated in the overlapping genomic AZFb-AZFc interval have been described in the literature [80][81][82] . Unfortunately, most of them did not address the basic question of whether the observed partial AZFb microdeletion was "de novo," and thus only found on the patients' Y chromosomes, or polymorphic because it was also found on the Y chromosomes of their fertile fathers.…”

Section: Azfb Gene Deletions and Male Infertilitymentioning

confidence: 99%

Human Y Chromosome and Male Infertility: Forward and Back from Azoospermia Factor Chromatin Structure to Azoospermia Factor Gene Function

Vogt¹,

Bender²,

Zimmer³

et al. 2017

Genetics of Human Infertility

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In the euchromatic part of the long arm of the human Y chromosome (Yq11) at least 13 Y genes encoding proteins and expressed in male germ cells were found in 3 distinct genomic Y regions frequently deleted in infertile men with idiopathic azoospermia, i.e., for unknown reasons no mature sperm were found in their semen fluid. Accordingly, they were designated as azoospermia factor (AZF) regions: AZFa, AZFb, and AZFc. Additionally, 10 Y genes called "testis-specific transcript Y" ( TTTY ) genes were mapped in the same AZF intervals. They belong to the long non-coding RNA gene pool in human germ cells because they seem to lack any protein-coding potential. Distinct chromatin regions in Yq11 overlapping with AZFb and AZFc are supposed to be involved in the premeiotic X and Y chromosome pairing and inactivation process controlling male germ cell meiosis. It can thus be assumed that the germ line function of the AZF loci in Yq11 may be not only based on the expression of some germ cell proteins, but also on the expression of some germ cell-specific TTTY transcripts and a locally dynamic and specific chromatin folding structure probably controlled by some germ cell-specific nuclear proteins.

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Association of Y chromosome AZF region microdeletions with recurrent miscarriage in Iranian couples: A case–control study

Pazoki,

Salehi,

Angaji

et al. 2024

Molec Gen & Gen Med

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BackgroundRecent studies have linked recurrent pregnancy loss (RPL) to abnormalities in the sperm genome, specifically microdeletions in the azoospermia factor (AZF) region. This study investigated the potential association between Y chromosome microdeletions in the AZF region and RPL in Iranian couples.MethodsThe research presents a case–control study of 240 men: 120 whose partners experienced recurrent miscarriage, and 120 who had successful pregnancies without history of miscarriage. The study used semen parameters, hormone analyses, and microdeletion analysis via multiplex PCR and the YChromStrip kit. Thus, the sequence‐tagged site (STS) markers of AZFa (sY84, sY86), AZFb (sY127, sY134), and AZFc (sY254, sY255) regions were examined.ResultsThe variations in semen parameters and sex hormone levels between cases and controls are suggest impaired testicular function in men whose partners had recurrent miscarriages (p < 0.05). Furthermore, the study revealed a negative correlation between sperm count and follicle‐stimulating hormone (FSH) level, and a positive one between sperm motility and testosterone concentration. There were no microdeletions in the control group, while the RPL group showed 20 deletions in AZFb (sY134) (16.66%) and 10 deletions each in AZFb (sY127) (8.33%) and AZFc (sY254) (8.33%).ConclusionMicrodeletions in sY134 (AZFb) were significantly associated with RPL in Iranian men (p = 0.03). AZF microdeletion screening in couples with RPL can provide valuable information for ethnical genetic counseling and management of recurrent miscarriage. Further studies on larger populations or across various ethnic groups, conclusions and the inclusion of other factors like epigenetic changes explain the role of AZF microdeletions in RPL.

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AZFb microdeletions and oligozoospermia—which mechanisms?

Cited by 47 publications

References 34 publications

Y-chromosome microdeletions in nonobstructive azoospermia and severe oligozoospermia

Y-chromosome microdeletions in nonobstructive azoospermia and severe oligozoospermia

Human Y Chromosome and Male Infertility: Forward and Back from Azoospermia Factor Chromatin Structure to Azoospermia Factor Gene Function

Association of Y chromosome AZF region microdeletions with recurrent miscarriage in Iranian couples: A case–control study

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