My point is that "where you were born" is a broader term than "the zip code where you were born." Obviously your zip code doesn't cause anything. But your zip code determines things like what the schools are like in the area, what the income demographics are like in the area, etc. When people say "where you were born determines where you end up" they're referring to that larger definition of "where you were born" not literally your zip code. That's what makes many versions of (4) collapse into (3).

Though I think your Tay-Sachs example is one that arguably does not.

Good parenting causes you to be born outside the southeast?