External and Genetic Conditions Determining Male Infertility

Abstract

We explain environmental and genetic factors determining male genetic conditions and infertility and evaluate the significance of environmental stressors in shaping defensive responses, which is used in the diagnosis and treatment of male infertility. This is done through the impact of external and internal stressors and their instability on sperm parameters and their contribution to immunogenetic disorders and hazardous DNA mutations. As chemical compounds and physical factors play an important role in the induction of immunogenetic disorders and affect the activity of enzymatic and non-enzymatic responses, causing oxidative stress, and leading to apoptosis, they downgrade semen quality. These factors are closely connected with male reproductive potential since genetic polymorphisms and mutations in chromosomes 7, X, and Y critically impact on spermatogenesis. Microdeletions in the Azoospermic Factor AZF region directly cause defective sperm production. Among mutations in chromosome 7, impairments in the cystic fibrosis transmembrane conductance regulator CFTR gene are destructive for fertility in cystic fibrosis, when spermatic ducts undergo complete obstruction. This problem was not previously analyzed in such a form. Alongside karyotype abnormalities AZF microdeletions are the reason of spermatogenic failure. Amongst AZF genes, the deleted in azoospermia DAZ gene family is reported as most frequently deleted AZF. Screening of AZF microdeletions is useful in explaining idiopathic cases of male infertility as well as in genetic consulting prior to assisted reproduction. Based on the current state of research we answer the following questions: (1) How do environmental stressors lessen the quality of sperm and reduce male fertility; (2) which chemical elements induce oxidative stress and immunogenetic changes in the male reproductive system; (3) how do polymorphisms correlate with changes in reproductive potential and pro-antioxidative mechanisms as markers of pathophysiological disturbances of the male reproductive condition; (4) how do environmental stressors of immunogenetic disorders accompany male infertility and responses; and (5) what is the distribution and prevalence of environmental and genetic risk factors.

Changes in Phenotypes and DNA Methylation of In Vitro Aging Sperm in Common Carp Cyprinus carpio

“…It is hypothesized that the representation and abundance of transcripts, including transcripts for methyltransferases, could be influenced by genetic failure or external stress stimuli during spermatogenesis [ 64 ]. Poor quality parameters and lowered viability of spermatozoa are often associated with environmental stress that is believed to be manifested in the observed phenotypes via epigenetic regulation.…”

Epigenetics in Male Infertility

“…Male infertility is a complex condition of which genetic, epigenetic and environmental lifestyle have been identified as major contributing factors [1][2][3]. In spermatogenesis, which is a complex of multistep differentiation process, millions of mature spermatozoa are daily produced by fertile male.…”

A Cross-Sectional Study of the Marital Attitudes of Pregnant Women at Risk for Cystic Fibrosis and Psychological Impact of Prenatal Screening

“…Cystic fibrosis (CF), identified as OMIM 219700, is the most prevalent hereditary condition in Caucasian populations, affecting one in every 2500–3500 live births, with a carrier prevalence of one in every 25–30 persons [ 1 ], which is caused by a monogenic autosomal recessive mutation in the CF transmembrane conductance regulator (CFTR) gene [ 2 ]. Even though the gradually worsening pulmonary disease is the leading cause of morbidity and mortality in these patients, the disorder is also characterized by pancreatic exocrine insufficiency, meconium ileus, liver disease, congenital bilateral absence of the vas deferens in males, and elevated sweat chloride concentration levels in its classical form [ 3 , 4 ]. Furthermore, the vast clinical spectrum correlated with CFTR gene mutations varies from severe classical CF with pancreatic insufficiency to delayed CFTR-related diseases such as bronchiectasis or male sterility, which is caused by a congenital bilateral absence of the vas deferens [ 5 ].…”