I suppose that's fair. Trivial literature review shows that there's nothing remotely resembling a discrete "SIDS gene", and that while there probably are genomic variations that can pose a subtle elevation of risk, that risk can't be evaluated outside the context of a given infant's environment and its effect on the likelihood of any such risk to materialize into SIDS proper. That genomic risk is so subtle that it can't even be quantified in the case of an individual infant; it's only discernible via broad whole-genome studies, and even their comprehensiveness and interpretation remains an open question [1].
So, in short, the framing of your prior comment, in which it can be cultural or it can be genetic, fails to capture the current best understanding - which is that it very probably is both cultural and genetic, and very probably as much or more the former than the latter.
The snark probably isn't all that justified, I grant. But I don't like the attitude of genetic essentialism toward which your prior formulation gestures. That kind of thinking is fully a century out of date at this point, and the extent of harm it's done in the world during and since its heyday strikes me as ample reason to regard it with suspicious distaste. In another context I doubt I would give it such a curt and pithy response, but I think a higher than usual epistemological standard is fair here, and the research I've just summarized for you is literally a single Google search away.
On the other hand, to construct that Google search requires that one know the term "GWAS" and what it means, so perhaps I've treated you a bit more harshly than you deserved. Still only a bit, though, I think; the kind of genetic essentialism I decry might have seemed reasonable a century ago, but these days it's sloppy thinking at best.
Worse, that same imputation of clear and discrete gene-level variation in complex, often behavioral, traits, across whole human populations, without any reproductive isolation to make such an idea even barely plausible even in a case where we're talking about traits that might potentially be primarily gene-linked - we call that "eugenics", a pseudoscience whose utter epistemological baselessness and staggering moral hazard are at this point I think clearly enough understood as to require no enumeration for anyone with even a rudimentary sense of history - at least I hope they are! If I'm wrong about that, we're all in for a deal of horror.
In any case, I suppose I've committed the error of expecting someone to know more than perhaps was reasonable, so I'll apologize for that. What you said deserved a critical response, rather than the glib one I initially gave it. I hope I've improved somewhat on that initial response here.