The results from my parents' genealogical DNA tests are in!
My mom's maternal line, which can be traced back to Ireland, belongs to haplogroup H. This is not very surprising — half of Europe shares this type of mitochondrial DNA.
My dad's paternal line is more unusual (for Europe): haplogroup E1b1b.
My paternal grandfather was born in Sassinoro, Benevento Province, which is near Naples and slightly North of the orange area on the map. His father was born in Buenos Aires, Argentina to parents from Sassinoro. As far as we can trace back, their ancestors also lived in the village (pop. 635).
The DNA evidence suggests that my ancestors may have lived in southern Italy before the Romans or may have been more recent immigrants from Greece, Turkey, or North Africa.