Question on Sperm fertility?

Question

If 2 parents of a male child are related by a great great grandfather, or a great great great grandfather, will the male child's sperm of the 2 parents be fertile?

Answer 1

i don't see why they wouldn't. do you mean because of in-breeding and mutations?  because in that case they're still fertile, it's just the chances of  mutations are increased. but that far back in the gene pool is far from that scenario. that mostly occurred with royal families who were trying to keep the family bloodline "pure"