Does the royal baby deserve genetic privacy? Revelations about the British princeling's ancestry should remind us that DNA testing is no big deal.

• Author: Bailey, Ronald
• Position: Columns

IN JULY, much of the world was thrilled by the birth of George Alexander Louis to the couple William Arthur Philip Louis Mountbatten-Windsor and Catherine Elizabeth, nee Middleton. The newborn stands third in line to be monarch of the rump remains of the British Empire. Given the celebrity of his parents and lineage, George Alexander Louis can expect little in the way of privacy. Even for his genes.

In June, the London Times published a front-page scoop unearthing "the Indian ancestry of William." Turns out the person second in line to the throne has a surprisingly multiethnic heritage.

The Times story was based on some genealogical and genetic sleuthing by the genetic testing company BritainsDNA. The company's scientists traced out the genealogy of Diana Spencer--the royal baby's deceased grandmother--and found that six generations back one set of Princess Di's ancestors consisted of an East India Company merchant named Theodore Forbes and his wife Eliza Kewark.

Kewark was a native of the Indian city of Surat, where her family identified its ethnic heritage as Armenian. To make a long story short, one of the couple's children, a daughter, moved to Scotland, married a local, had kids, and so on down the generations, all the way until little George.

BritainsDNA's research identified a couple of distant relatives who, like Diana, are direct matrilineal descendants of Eliza Kewark. The two were tested, and indeed they carry Eliza's rare version of mitochondrial DNA. Mitochondria, the tiny power plants inside cells, have their own small and distinctive set of genes, which are inherited mostly unchanged from a person's mother. Eliza's R3ob haplogroup has been found so far only in people living in South Asia. If the cousins carry that type of mitochondria, then so too would Diana and her children.

Other tests indicated that the genetic makeup of the cousins was also about 0.3 percent to 0.8 percent South Asian. The rest of their DNA was of European origin.

George Alexander Louis inherited his mitochondria from his mother and so does not carry Eliza Kewark's R3ob version. Nevertheless, the folks at BritainsDNA suggested that it's "very likely" William's progeny will carry at least a trace of subcontinental DNA.

More likely not. There's a big difference between genealogical ancestry and genetic ancestry. Ten generations back, a person has 1,024 genealogical ancestors, but given the vagaries of genetic recombination and sexual reproduction it is...