BACKGROUND AND
OBJECTIVE:Chromosomal or mitochondrial DNA abnormalities are the main
causes of male infertility. So far, a lot of genes are identified on X and Y
chromosomes that control the spermatogenesis process in a special order. Y
chromosome genes have an important role in sex determination and male
reproduction process, and so any mutation or disruption on the Y chromosome
genes effects on male fertility. In this study, several kinds of genetic disorders
and new area of gene and mutation damaging on the Y chromosome was
investigated.
METHODS:In this review
article the genetic abnormalities induced by molecular mutations on Y
chromosome was investigated.Papers pertaining to gene polymorphisms, abnormal
spermatogenesis, genetic evaluation andandrogen receptor genes were used.Microdeletions,
chromosomal abnormalities, molecular genetics, environmental conditions were
also studied.
FINDINGS:Among
2000 genes involved in spermatogenesis, only 30 genes are located on Y
chromosome. Environmental condition, hormonal and immune disorders,
antioxidants, genetic factors and elements deficiency are effective in male
infertility. Y chromosome abnormalities usually associated with the removal of
some factors. Genes on Y chromosome usually have an important role in
spermatogenesis and testes development.
Chromosomal translocation and loss of
genetic material cause infertility. Microscopic deletion is usually transmitted
to sons and their infertility cannot be solved even using the ICSI technique.
Effect of genes polymorphism on male fertility is associated with a decrease in
sperm count.
CONCLUSION:Azoospermic
factor region on human Y chromosome contains a lot of genes which any mutation
or deletion in these genes lead to impaired spermatogenesis and low sperm
fertilization. |