Majallah-i Dānishgāh-i ̒Ulūm-i Pizishkī-i Bābul (Nov 2014)
Most Common Genetic Abnormality and Molecular Mutations on Human Sperm Y Chromosome and their Effects on Male Infertility
Abstract
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.
