If a man is found to have no sperm in the ejaculate (Azoospermia) it may be necessary to look more closely with a blood test at the male genetic profile. Rarely men will carry a genetic abnormality affecting sperm production.
Important genetic conditions that can affect sperm production are best discussed with a fertility or genetics specialist. The genetic tests likely to be performed, if you are found to have no sperm in the ejaculate, are a karyotype, a Y-microdeletion and a cystic fibrosis screen.
Cystic Fibrosis is a genetically inherited condition that causes lung disease primarily but it can also cause male infertility. Some men are born with this condition but are also noted to have absence of the vital pipe connected to the testes, so sperm do not reach the ejaculate. A cystic fibrosis blood test screens for the condition when there is no sperm in the ejaculate.
Chromosomes are found in every cell in our bodies and they carry the DNA that makes us who we are. If there are abnormal numbers or structures of chromosomes this can affect fertility. A karyotype blood test looks at our chromosomes and it searches for abnormal numbers or structures of chromosomes. A missing gene on the Y-chromosome can also be checked for with these tests and is checked for as this is known to affect sperm production in some cases. A fertility specialist can discuss genetics tests with you in more detail.