If a child is born of drow and high elf parents, Would they be a mix of both besides just physical appearance?

If a child is born of drow and high elf parents, Would they be a mix of both besides just physical appearance? Or would they be one or the other in terms of race? I think it could be either – my sense based on the mythology of elves is that the elf would take on one of the two forms

— Mike Mearls (@mikemearls) March 6, 2018