How was DNA Used to Verify the Identity of Osama bin Laden
May 1st, 2011 marks the final chapter in a manhunt that has consumed many in the U.S. Intelligence Community
It has been reported that DNA Testing has provided a "99.9% certainty" that the person shot to death in Abbottabad Pakistan was Osama bin Laden. As with any high profile news story, the media has exploded with theories and speculation about the possibility DNA testing is capable of producing definitive results in such a short period of time.
As our laboratory performs the same relationship testing on over 60,000 samples per year, we clearly understand that with proper preparation, DNA identification is possible in a time frame of less than 6 hours.
There is considerable speculation, which has spawned numerous phone calls this week regarding the probable nature of testing. One of the issues other than timing is, "Who did they compare it to?" It has not been disclosed at this point, but considering the result of 99.9% and available relatives, one would assume a siblingship. Osama bin Laden's father had 54 children with 22 wives. Osama was the only child Alia Ghanem had with his father, which rules out full siblingship. However, there is obviously a host of half siblings that could be used to determine half siblings. Osama is also thought to have fathered 26 children.
It has been asked if the Intelligence Community may have had his full profile from a variety of touch DNA samples. If bin Laden's full profile was known, you would have a much higher probability than 99.9%. It is unknown how many siblings or other relatives were used in the family reconstruction. The number needed in order to reach the reported degree of certainty would depend on several factors, most importantly the commonality of any unusual features in bin Laden's genetic makeup. "If he had very rare alleles (gene variants), one family member might be enough to get certainty," John Butler, a leading expert on forensic DNA analysis at the National Institute of Standards and Technology (NIST), told Innovation News Daily, "If he has a common genetic profile, you might need more relatives".
The use of Y-STR testing, and comparison with male members of the patrilineal line would be able to tell if the decedent was one of many half brothers, cousins and so on, but would not provide definitive evidence of his identity. It would however, help narrow things down. Y-chromosome testing was used in lineage determinations with cases such as Thomas Jefferson and Saddam Hussein. It has been reported that DNA had been collected from a half sister of Osama bin Laden who had died in Massachusetts. It is likely that DNA has over time been collected from other relatives. Using the same test kits which contain the 13 CODIS STR (Short Tandem Repeats) loci, plus many others, family reconstruction is possible. NIST has developed a long list of discriminating STR loci that can be used to boost the confidence of kinship statistics.
If bin Laden's relatives can be persuaded to provide DNA samples for identification, the kinship probabilities could strengthen from the already highly compelling evidence. ABC News has reported that U.S. Officials had asked bin Laden relatives for DNA samples after they thought he may have been killed in a missile strike last February. If bin Laden's mother, now known as Hamida al-Attas, could be persuaded to provide a DNA sample, the probability of relatedness could improve exponentially. However, combining the existing DNA probabilities with the additional probability of a 6 foot four inch tall Arab man, in a compound in Abbottabad the probability of identification is strong.
May 1st, 2011 marks the final chapter in a manhunt that has consumed many in the U.S. Intelligence Community
It has been reported that DNA Testing has provided a "99.9% certainty" that the person shot to death in Abbottabad Pakistan was Osama bin Laden. As with any high profile news story, the media has exploded with theories and speculation about the possibility DNA testing is capable of producing definitive results in such a short period of time.
As our laboratory performs the same relationship testing on over 60,000 samples per year, we clearly understand that with proper preparation, DNA identification is possible in a time frame of less than 6 hours.
There is considerable speculation, which has spawned numerous phone calls this week regarding the probable nature of testing. One of the issues other than timing is, "Who did they compare it to?" It has not been disclosed at this point, but considering the result of 99.9% and available relatives, one would assume a siblingship. Osama bin Laden's father had 54 children with 22 wives. Osama was the only child Alia Ghanem had with his father, which rules out full siblingship. However, there is obviously a host of half siblings that could be used to determine half siblings. Osama is also thought to have fathered 26 children.
It has been asked if the Intelligence Community may have had his full profile from a variety of touch DNA samples. If bin Laden's full profile was known, you would have a much higher probability than 99.9%. It is unknown how many siblings or other relatives were used in the family reconstruction. The number needed in order to reach the reported degree of certainty would depend on several factors, most importantly the commonality of any unusual features in bin Laden's genetic makeup. "If he had very rare alleles (gene variants), one family member might be enough to get certainty," John Butler, a leading expert on forensic DNA analysis at the National Institute of Standards and Technology (NIST), told Innovation News Daily, "If he has a common genetic profile, you might need more relatives".
The use of Y-STR testing, and comparison with male members of the patrilineal line would be able to tell if the decedent was one of many half brothers, cousins and so on, but would not provide definitive evidence of his identity. It would however, help narrow things down. Y-chromosome testing was used in lineage determinations with cases such as Thomas Jefferson and Saddam Hussein. It has been reported that DNA had been collected from a half sister of Osama bin Laden who had died in Massachusetts. It is likely that DNA has over time been collected from other relatives. Using the same test kits which contain the 13 CODIS STR (Short Tandem Repeats) loci, plus many others, family reconstruction is possible. NIST has developed a long list of discriminating STR loci that can be used to boost the confidence of kinship statistics.
If bin Laden's relatives can be persuaded to provide DNA samples for identification, the kinship probabilities could strengthen from the already highly compelling evidence. ABC News has reported that U.S. Officials had asked bin Laden relatives for DNA samples after they thought he may have been killed in a missile strike last February. If bin Laden's mother, now known as Hamida al-Attas, could be persuaded to provide a DNA sample, the probability of relatedness could improve exponentially. However, combining the existing DNA probabilities with the additional probability of a 6 foot four inch tall Arab man, in a compound in Abbottabad the probability of identification is strong.
Article from Chromosomal Laboratories.
No comments:
Post a Comment