The causes of male infertility are often systemic diseases, malnutrition, endocrine disorders, anatomical disorders of sperm transport, infections, and environmental toxins. In addition, about 11% of patients have an unknown cause. This is called idiopathic infertility. The most common symptoms are azoospermia and oligospermia. Molecular biology techniques have shown that male idiopathic infertility is associated with genetic factors, especially genetic factors on the sex chromosomes. Alterations or deletions in the order of DNA bases are called genetic defects. Gene defects can be either defects in whole genes or defects in points. Gene defects can be inherited either in a dominant manner; or in a recessive manner. There can be different exons. When an exon (Exon) is defective, the protein encoded is altered, which causes a significant change in the phenotype (Phenotype). When an Intron is defective, it is more subtle but can affect the amount of protein produced, thus reducing the ability to synthesize the starting DNA protein.