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Assessment and Diagnosis of the Male Infertility Patient
Published in Botros Rizk, Ashok Agarwal, Edmund S. Sabanegh, Male Infertility in Reproductive Medicine, 2019
Muhannad M. Alsyouf, Cayde Ritchie, David Kim, Edmund Ko
The Y chromosome is essential for spermatogenesis and testicular development [2]. Y-chromosome microdeletions have been associated with spermatogenic impairment with the severity of which is related to the location of involvement. The most common Y-chromosome region that is related to infertility is the azoospermia factor locus (AZF) that contains subregions controlling different steps of spermatogenesis known as AZFa, AZFb, and AZFc. AZF microdeletions represent the most frequent molecular genetic cause of azoospermia and severe oligoozospermia [33]. Microdeletions involving AZFa and AZFb are associated with germ cell aplasia and arrested maturation, and attempts at sperm retrieval are not recommended in patients harboring these deletions because there is no chance of finding testicular sperm [34,35]. In microdeletions involving the AZFc region, sperm extraction yields a 71%–80% success rate [36].
Andrological causes of recurrent implantation failure
Published in Efstratios M. Kolibianakis, Christos A. Venetis, Recurrent Implantation Failure, 2019
Chrisanthi Marakaki, Georgios A. Kanakis, Dimitrios G. Goulis
Microdeletions of the various azoospermia factor (AZF) regions on the long arm of the Y chromosome are another major genetic factor involved in male infertility.22 Deletions of the AZFa and AZFb regions are typically associated with azoospermia and absence of sperm during testicular sperm extraction (TESE) procedures. On the other hand, deletions of the AZFc region result in a less-severe defect of spermatogenesis, allowing successful TESE or even the presence of sperm in the ejaculate. It is reported that the clinical outcomes of ICSI for oligozoospermic/TESE patients with AZFc microdeletions are comparable to those of infertile patients with normal Y chromosomes,23,24 in contrast to previous studies that associated AZFc microdeletions with lower fertilization rate and poorer embryo quality.25 Thus, the correlation between the incidence of AZF microdeletions and ART results remains controversial and needs to be verified in a large cohort of infertile men.
Sex Chromosome Anomalies
Published in Merlin G. Butler, F. John Meaney, Genetics of Developmental Disabilities, 2019
L. Hamerton John, A. Evans Jane
Sex chromosome aneuploidy, with the exception of 47,XXX and 47,XYY, generally leads to impaired fertility. Clearly, either two X chromosomes or one X and one Y are required for normal sexual development. Having a single X chromosome leads to significant lethality during gestation and those fetuses that do survive to term are generally infertile as adults. The Y chromosome is not required for survival, but is essential for the normal development of the testis, including the formation of seminiferous tubules, the migration of the germ cells into the tubules, and their maturation to form spermatozoa. Initially, it was thought that the Y chromosome was only required to ensure that the bipotential gonad developed into a testis. In 1976, however, Tiepolo and Zuffardi (161) reported that the Y chromosome was also involved in the control of spermatogenesis. They observed deletions including Yql2–Yq11 in six sterile males. Two of the fathers had normal Y chromosomes suggesting a de novo event and a causal relationship. These authors postulated that a genetic factor located at Yq11 was important in male germ cell development. This gene or gene cluster was named the “azoospermia factor” (AZF). Molecular mapping of the Y chromosome in infertile men has revealed three nonoverlapping deletions, termed AZFa in Yq11.21, AZFb in Yq11.22, and AZFc in Yq11.23 in the euchromatic portion of the long arm (162–164). Several candidate genes for the AZF phenotype have now been identified in these regions (165).
Screening by single-molecule molecular inversion probes targeted sequencing panel of candidate genes of infertility in azoospermic infertile Jordanian males
Published in Human Fertility, 2022
Osamah Batiha, George J. Burghel, Ayesha Alkofahi, Emad Alsharu, Hannah Smith, Bilal Alobaidi, Mohammad Al-Smadi, Nour Awamlah, Lama Hussein, Amid Abdelnour, Harsh Sheth, Joris Veltman
Male infertility is a multifactorial disease encompassing a wide variety of disorders and can be initially diagnosed by semen analysis (Poongothai et al., 2009). Genetic factors play a major role in idiopathic male infertility (Al Zoubi, Al-Batayneh, et al., 2020; Al Zoubi, Bataineh, et al., 2020; Plaseska-Karanfilska et al., 2012). The main genetic cause of male infertility is chromosomal abnormalities, which accounts for ∼5% of infertile males, and the prevalence increases to 15% in azoospermic males (Krausz & Riera-Escamilla, 2018; Zorrilla & Yatsenko, 2013). Men with non-obstructive azoospermia have a high prevalence of aneuploidy, particularly in their sex chromosomes. The second most common genetic cause of male infertility is Y chromosome microdeletions affecting the azoospermia factor (AZF) region (Batiha et al., 2012; Zorrilla & Yatsenko, 2013). Microdeletions in this region cause defects in spermatogenesis that lead to the development of azoospermia and oligozoospermia (Krausz & Riera-Escamilla, 2018). There are also male infertility cases caused by defects in single genes including CFTR, DDX3Y, SYCP3, TEX11, AURKC, and DPY19L2, but the number of genes confidently linked to male infertility remains very low (Oud et al., 2019). The poor genetic diagnosis makes a large proportion of infertile males falling in the ‘idiopathic infertility’ category with no obvious reasons explaining their infertility problem.
Genetic aspects of idiopathic asthenozoospermia as a cause of male infertility
Published in Human Fertility, 2020
Zohreh Heidary, Kioomars Saliminejad, Majid Zaki-Dizaji, Hamid Reza Khorram Khorshid
Elfateh et al. (2014) investigated the influence of genetic abnormalities on semen quality and reproductive hormone levels of 691 infertile men from Northeast China with abnormal sperm parameters and found abnormal chromosomal karyotype in 12% of patients. From these men, there were one AZS with Klinefelter’s syndrome, one AZS and two OAS with chromosomal polymorphism, one OAS with XYY syndrome, one AZS and four OAS with robertsonian translocation, one AZS and five OAS with reciprocal translocation. Azoospermia factor (AZF) region microdeletions in infertile men with normal karyotype were detected in six OAS (AZFb and AZFc) and one AZS (AZFc) and AZFc deletion in two OAT (Elfateh et al., 2014). Similarly, AZF microdeletion was detected in 1/6 OAS patients, while no microdeletions were found in normozoospermic and asthenozoospermic men (Khan, Ganesan, & Kumar, 2010).
Predictive factors for sperm retrieval from males with azoospermia who are eligible for testicular sperm extraction (TESE)
Published in Systems Biology in Reproductive Medicine, 2020
Doroteja Pavan-Jukic, David Stubljar, Tomislav Jukic, Andrej Starc
Azoospermia is defined as a lack of sperm in the ejaculated semen and is found in approximately 10–15% of infertile men (Irvine 1998). The most common cause of infertility in 60% of the cases is due to non-obstructive azoospermia (NOA), a condition associated with impaired production of sperm (Willott 1982), followed by obstructive azoospermia (OA), a lack of the azoospermia factor (AZF) at the c region of the Y chromosome and Klinefelter syndrome (KS). Despite there might be an impression of the absence of spermatozoa in the ejaculate, sperm from NOA, may still be retrieved due to active spermatogenesis (Eken and Gulec 2018). In 1993 for the first time, and in several later studies testicular sperm extraction (TESE)-intracytoplasmic sperm injection (ICSI) was described as a procedure to significantly increase the possibility of pregnancy (Craft et al. 1993; Schoysman et al. 1993; Vernaeve et al. 2003; Kyono et al. 2007). During the time, TESE as a surgical technique improved and variants developed; multibiopsy/conventional TESE, microdissection TESE and testicular sperm aspiration (TESA) (Craft et al. 1993; Bourne et al. 1995; Schlegel and Li 1998).