Actually it turns out that I am as white genetically as I am Whyte nominally. My genetic heritage is summarised as follows:
With three grandparents born in Ireland to Irish families, and the fourth East Coast aristocracy (born in Philadephia, raised in Plainfield NJ, uncle was Taft's Attorney-General), it was always unlikely that I had much ancestry from outside north-west Europe. But I must admit I had hoped for more than 1.4%
Mitochondrial DNA: I'm in haplogroup V8, which is a little exotic as maternal lineages go. V in general accounts for only 4% of Europeans; it is particularly concentrated at two ends of the wider northeastern Atlantic space, the Saami of Finland and my friends the Saharawi of Western Sahara. The theory is that it was common among the population of Doggerland, now lost beneath the North Sea. Two famous people are known to share the V haplogroup with me - Benjamin Franklin and Bono.
V8 is noted rather cryptically as being "found in Sweden"; closer investigation reveals that this means three people were found to have it in Västernorrland. My great-grandmother lived to 98 (and her daughter turns 100 next month); her ancestry was Ulster Scots, as far as we know. My children will have their mother's mitochondrial DNA, but my brother, my sister and her daughter will all have inherited V8 from our mother.
Y-Chromosome: My paternal lineage is haplogroup G2a4 or G2a2b, a subgroup of haplogroup G which is found particularly in the Caucasus (appropriately enough I was in Tbilisi when I got the results).
Other things being equal, this should be the ancestral Whyte heritage; family lore is that we were descended from the Jutes who settled the Isle of Wight, and then came to Ireland in 1170-90, but I am not sure that current thinking about the etymology of the Isle of Wight really supports this.
However, my rather rare G2a4 or G2a2b subgroup does include one famous person who is therefore my direct male-line relative, even if we do not know his name: it is Ötzi the Iceman. Data seems sparse, but it seems to be concentrated more to the west than G as a whole. My brother and my son will have the same Y-chromosomes as me. We are the only male-line descendants of my great-great-grandfather - my father had just one sister, my Whyte grandfather was one of nine brothers (with six sisters!) but the other eight produced only one daughter between them, and my Whyte great-grandfather had two brothers, one of whom died young and the other had only daughters who survived to adulthood. The survival of these lineages can be very fragile.
Neanderthal ancestry: 2.7%, which is dead on the average for 23andMe users (in the 53rd percentile, apparently).
Long-lost relatives: Two other 23andMe users popped up sharing more than 1% of my DNA. One is a cousin of my American grandmother's who I'd already been in touch with years ago, whose grandmother was my great-grandmother's sister. The other appears to be a connection via the Ryans of Inch, one of whom married my Whyte great-grandfather. I may drop him a note.
Anyway, a fascinating look at what has made me what I am.