MALE INFERTILITY AS A RESULT OF GENETIC DISORDERS (REVIEW)

Abstract

Infertility is a very complex international problem that involves 15% of family couples and approximately one third of cases are associated with male reproductive failure. The percentage of infertile men ranges from 2-5% to 12%. In 30% – 40% of cases there was no factor found associated with male infertility, the phenomenon being named idiopathic male infertility. A said group includes men without anamnesis of fertility and any negative consequences of endocrine, genetic and biochemical laboratory examinations. Most of these idiopathic cases are likely to be of genetic origin because, as we know, the number of genes that are involved in human spermatogenesis is over 1 thousand. Genetic disorders of male reproductive system can be divided into 4 groups: chromosomal (numeric/structural) anomalies and microdeletions of Y chromosome, disorders of determination of sex/sexual differentiation, disorders of hypothalamic-pituitary-gonadal regulation, disorders of producing and functioning of sperm. Spermatozoa of infertile men possess a higher risk of aneuploidy, structural chromosome abnormalities, DNA disorders and the risk of transmission of genetic defects to off springs. Chromosomal pathology is the leading reason of spermatogenic failure. Frequency of chromosome abnormalities increases with aggravation of testicular failure severity. A patient with a number of spermatozoa in ejaculate less then 5 millions per ml is characterized by ten times as much frequency (4%) of autosomal abnormalities as compared to the whole population. Men with non-obstructive azoospermia possess a higher degree of the risk of gonosome abnormalities. One more problem of genetic disorders is DNA fragmentation in spermatozoa. Men with oligozoospermia have a higher risk of DNA lesion in spermatozoa. This tendency is directly connected with a lower ability to natural fertilization and chance increase to preterm interruption of pregnancy. Oxidative stress is the major cause of DNA fragmentation in male infertility but may be modifiable in many cases. Considering the above mentioned, it can be noted that genetic disorders play a great role in male reproductive failures. All the professionals involved in the field of andrology should be well familiar with the issues of genetic abnormalities associated with infertility to ensure correct medical tactics provided to family couples requiring it.

Keywords

• male infertility
• genetic disorders
• chromosome anomalies