Saturday, November 05, 2005

New Scientist News - Anonymous sperm donor traced on internet

Anonymous sperm donor traced on internet

LATE last year, a 15-year-old boy rubbed a swab along the inside of his cheek, popped it into a vial and sent it off to an online genealogy DNA-testing service. But unlike most people who contact the service, he was not interested in sketching the far reaches of his family tree. His mother had conceived using donor sperm and he wanted to track down his genetic father.

That the boy succeeded using only the DNA test, genealogical records and some internet searches has huge implications for the hundreds of thousands of people who were conceived using donor sperm. With the explosion of information about genetic inheritance, any man who has donated sperm could potentially be found by his biological offspring. Absent and unknown fathers will also become easier to trace.

The teenager tracked down his father from his Y chromosome. The Y is passed from father to son virtually unchanged, like a surname. So the pattern of gene variants it carries can help identify which paternal line an individual has descended from and can also be linked to a man's surname.

The boy paid FamilyTreeDNA.com $289 for the service. His genetic father had never supplied his DNA to the site, but all that was needed was for someone in the same paternal line to be on file. After nine months of waiting and having agreed to have his contact details available to other clients, the boy was contacted by two men with Y chromosomes closely matching his own. The two did not know each other, but the similarity between their Y chromosomes suggested there was a 50 per cent chance that all three had the same father, grandfather or great-grandfather.
“Many have not told their families and never considered the implications of having a dozen offspring wanting to meet them”

Importantly, the men both had the same last name, albeit with different spellings. This was the vital clue the boy needed to start his search in earnest. Though his donor had been anonymous, his mother had been told the man's date and place of birth and his college degree. Using another online service, Omnitrace.com, he purchased the names of everyone that had been born in the same place on the same day. Only one man had the surname he was looking for, and within 10 days he had made contact.

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