The problem with DNA tests (most of them, as far as I know), is that they get their results by nationalities, not race. For example, one might get a 100% Norwegian result. But Norwegians aren't 100% Nordic. There is a little bit of Mongol ancestry there. Or 100% Serbian means little as Serbs aren't 100% Slavic. There is quite some Mediterannean and Turkish (which in itself contains Mongol) ancestry there. If they used racial terms (Slavic, Baltic, Celtic, Nordic, Mongol, Middle-Eastern, North African, sub-Saharran African, Aboriginal etc), they'd be more precise and conclusive.