1. What does it mean that AZF gene microdeletion on Y chromosome is negative?

The chromosome Y, which determines male sex, is the carrier of genetic material. There are 23 pairs of human chromosomes (i.e. 46), 22 of which are autosomes, the same for men and women; the remaining pair are sex chromosomes, the female chromosome is composed of two identical chromosomes, written as XX, the male chromosome is composed of an X chromosome and a Y chromosome, written as XY, and the Y chromosome is determined by the male sex.
According to the statistics of the World Health Organization, 10% of couples in the world suffer from infertility, and male infertility accounts for about half of them, and more than 30% of them are caused by genetic abnormalities. Microdeletion of Y chromosome is the main genetic factor of male infertility.