Tuesday, September 23, 2008

A Genetealogy Dilemma - Any Ideas?

At the CGSSD meeting on Saturday, a lady in the audience posed this problem to the speaker, Barbara Bowling Gosink, an expert in DNA research:

"I don't know who my father is. He and my mother had relations in Naples, Italy back in the 1950's and I was born. I have no siblings. My mother did not tell me his name and there is no father's name on my birth certificate. Can DNA research help me?"

As I recall, the answer from Barbara was essentially "no" if the name is unknown and she has no male sibling from the same father. With a name and a male sibling, research could be done in Naples to find family members with the surname and they could be tested in hopes of finding a Y-DNA match. But she has no male sibling to test Y-DNA, and mitochondrial DNA is not passed from the father, so there is no hope of determining the father's identity.

Is all of that correct? Are there any other opportunities based on the whole genome of this woman, comparing the genome of her mother (assuming a sample is available), and determining the parts of her DNA she inherited from her father, then finding a match somehow with genomes of persons in Italy? That's a big order, but it might be possible at some time in the future. Perhaps there are sperm bank or criminal blood samples from the time period in Naples that could be compared.

Is that too far-fetched? Even for 20 years from now? I would appreciate any thoughts on how to help this woman with her search for her father.

I am in awe of the research that has gone into developing genetic genealogy over the past ten to twenty years. It is incredibly complex, and they have managed to reduce it to fairly simple terms and relatively low costs for Y-DNA and mtDNA testing.


Anonymous said...

She could get lucky. Say she has a rare hereditary trait from her father's side, and the Naples hospital has a researcher with a database.

But the most important thing is to ask aunts and uncles to tell everything they know.
They'd would not bring it up because it is awkward and are likely to assume that mother told everything already.
They probably remember things mother explained to them back then.
Don't forget the family physician either.

TheGeneticGenealogist said...

I just had someone ask this question at the FGS conference 3 weeks ago (same person, or a common occurrence?), so I’ll give the same answer I gave her. I agree that AS OF TODAY, there is little to no hope that the woman will discover the identity of her father. However, people always tend to think this situation will never be resolved because there is no Y-DNA to use. Of course, as we all know, the woman inherited 50% of her genome from her father. It is my hypothesis that somewhere in that DNA is a clue to her father’s ancestry which can ultimately be used to identify her father.

How will autosomal (non-sex chromosome) DNA reveal her father’s identity? As genomic sequencing becomes cheaper and cheaper, it will be possible to sequence an entire genome relatively cheap (first under $1,000, then eventually under $100). Undoubtedly, with this cheap technology, genealogical and medical organizations will use vast autosomal DNA and family chart databases to trace genes and mutations through genealogies. SMGF, for example, is already collecting both DNA (although it is currently limited to Y-DNA and mtDNA) and family charts, and I believe that they have plans to use autosomal DNA in the future.

Additionally, earlier this year a deadly mutation that leads to colon cancer was traced to an English couple that emigrated to the United States hundreds of years ago. Although not everyone with this mutation is descended from this couple, many are; thus, if you have the mutation, it is very possible that you are descended from this couple and this would provide a clue to your ancestry that could be explored with traditional genealogical research. With cheap sequencing we will be able to trace unimportant ‘quiet’ mutations through time and genealogies, just as scientists have already done with many dangerous mutations.

So how will all this help the woman identify her father? Someday in the very near future she will be able to query her genome against a database of genomes and ancestries. Just as a deadly colon cancer mutation can be linked to a certain family, it is likely that the woman has one or more random mutations in her genome that are linked to certain families. Using traditional genealogical research (to rule out inheritance of those mutations through her mother, for example) and genetic technology, she might be able to use that knowledge to identify possible sources of half her DNA.

Unfortunately, the scenario I posit requires two things which are not currently available: first, cheap and widely-available genomic sequencing; and second, one or more databases compiling autosomal DNA and genealogies which can be queried.

(Note also that this method would not require any DNA directly from the father or even any 1st or 2nd order relatives; yet another benefit).