Can stork bites be genetic?

My son & newborn daughter's dad has a stork bite on the back of his head/neck that never went away, my son was born with one in the exact same spot, and my now 3 week old daughter has one in the same exact spot also. My older daughter (not related to my other two children's father) does not have one, never did, and neither do/have I. Could they or are they genetic? It only seems to make sense to me, but everything I read said "not usually". Anyone out there have any similar stories or ideas?