Boyfriend suspects he has higher chance of having a son?

Patient: In my boyfriend’s family there had been 5 generations of just males. He therefore suspects that he might have a condition where he can only produce male sperm – does this exist? I know this sounds ridiculous but I’m just curious.

Symptoms: 5 generations of males?

Doctor: Hello,There is no such condition and likelihood as the male sperm has both X and Y alleles. There is equal likelihood that any one of them would fertilise the X allele ovum making it either XX ( FEMALE) or XY( male) FETUS. So, it is a natural selection and there is no such entity as to that it is genetically related , it is purely a matter of natural selection.I hope i have answered your query,wishing you good health,regards