Sperm formation is regulated by the genes on chromosomes and any defects on these regions can lead to problems in sperm formation, development and differentiation.
Genetic diseases may also negatively affect the sperm formation due to different mechanisms. That is why couples should be informed and suggested to take chromosome analysis and alike tests, unless the reason behind infertility has been identified.
If any genetic disorder is determined, then couples should be informed about possible risks and the things what they are expected to do prior and during the pregnancy period.