Can sids come back in the same family?

In some families. The medical literature has reported that an occasional familial risk has been noted. In one case i know of, a mother found that she and her husband were first cousins without their prior knowledge.First cousin marriages are at risk of both partners carrying the same recessive gene. I think that this is uncommon if not rare.
Unlikely if ever. Unfortunately, this rare event has sometimes been found to represent child abuse rather than a genetic event.One such family had 3 losses before mothers mental illness was uncovered and previous "familial" sids speculation ended. It could happen, but is is important for every infant death to be thoroughly evaluated.