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The first practical test of DNA fingerprinting involved a two year struggle by Christiana Sarbah and her son, Andrew,
to prove to the Home Office in England that they were, indeed, mother and son. The ordeal began in 1983 when Andrew, then
13, arrived in England after a long stay in Ghana with Christiana's estranged husband. Immigration officials held him at Heathrow
Airport, claiming his passport was forged, or that a substitution had been made. Only after intervention by Member of Parliament
Martin Stevens was Andrew allowed to stay at his family's home in London.
Workers at the Hammersmith Law Centre, which provides legal aid to the under-privileged, amassed huge amounts of evidence,
including photographs and statements by family members. Various tests to determine genetic characteristics showed that Christiana
and Andrew were almost certainly related. However, the tests could not determine whether Christiana was his mother or merely
an aunt (Christiana has several sisters in Ghana). The photographic evidence and depositions were rejected at an immigration
hearing, but deportation was delayed pending an appeal.
After reading in the local newspaper about a scientific discovery that could prove maternity, Centre workers contacted
Alec Jeffreys at Leicester University, and asked him to take on the case. Jeffreys accepted, believing it would be an ideal
test of the DNA fingerprint technology he had recently developed. Jeffreys used DNA extracted from blood samples from Christiana,
Andrew, an unrelated individual, and Christiana's three undisputed children: David, Joyce, and Diana. Using his multilocus
probe, Jeffreys produced the DNA fingerprints. He compared the banding patterns of all the individuals.
One of the possibilities that was difficult to disprove using other methods was that Christiana was, in reality, Andrew's
aunt – a sister of his true mother. Alec Jeffreys showed that Andrew's DNA fingerprint contained about 25 bands that
were inherited from his mother. The possibility that Christiana is the "true" mother's sister and yet share 25 bands with
her (and Andrew) is one in 600,000.
Although Andrew's father's DNA was not available, Jeffreys reconstructed the father's DNA fingerprint from bands present
in Christiana's three other children, but absent in Christiana. About half of Andrew's bands match bands in the father's compilation
and the remaining bands were all present in Christiana's fingerprint. The possibility of this happening by chance is less
than one in a trillion.
The Home Office accepted the DNA fingerprint evidence, and allowed Andrew to stay in England with his mother and siblings.
The Home Office also announced that it would not contest future immigration cases if similar DNA evidence were available.
To read the actual newspaper article, printed in 1985, about Andrew Sarbah click on the link below, go to
human identification, then family, then read the article.
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