Scientists say Tutankhamun died of malaria
CAIRO // It was a mundane case of malaria - not murderous royal intrigue or a dashing fall from a chariot - that likely killed the Ancient Egyptian boy king, Tutankhamun, more than 3,000 years ago, according to a new genetic study released yesterday.
But if the medical realities behind the death of Egypt's best-known king were anything but exotic, the science that led to yesterday's discoveries pioneered new methods in the multidisciplinary field of paleogenetics and may eventually lead to the emergence of a new field called molecular Egyptology. Never before, said scientists involved in the project, have such complete genetic samples been recovered from ancient Egyptian mummies.
"I never thought we could have the DNA of a mummy dating back 3,000 years ago," said Zahi Hawass, the secretary general of Egypt's Supreme Council of Antiquities, who spoke to reporters in downtown Cairo's Egyptian Museum yesterday. "But we did." The results of two years of genetic inquiry into the boy king's lineage, health history and cause of death were published yesterday in the Journal of the American Medical Association. The study by a joint group of German and Egyptian scientists also determined the familial relationships among 11 royal mummies from the New Kingdom period of Ancient Egyptian history and offered important new insights into Tutankhamun's own health and family history.
The results paint a detailed genetic portrait of one of one of ancient history's most enigmatic figures. Contrary to the idealised popular impressions of the charmed boy king, who ruled from the age of nine until his death at age 19 in 1323BC, yesterday's study depicts a frail young man who suffered from multiple life-threatening illnesses and probably walked with a cane because of his club foot. Scientists confirmed yesterday that Tutankhamun's less-than-regal aspect may have come from faulty genes: his mother and father were also brother and sister. While such a pairing was probably not considered incestuous among ancient Egypt's ruler-deities, it might have given Tutankhamun a deficient immune system that led to an early death. Sophisticated genetic tests revealed evidence of malaria tropica, a particularly nasty strain of the mosquito-borne tropical disease.
And while much of the new information will only add to the long-dead king's pop icon stature, scientists involved in the project said their study has "showed the feasibility of gathering data on Pharaonic kinship and diseases" from genetic samples in a way that may help unravel future mummy mysteries. "DNA fingerprinting as a technique has been used before for identifying the Romanov family, for example. It has been applied in contemporary forensic science to identify disputed paternity cases and solve criminology and forensic cases," said Yehia Gad, a professor of molecular genetics at Cairo's National Research Center, who said he and his team were able to see "full fingerprints" or DNA profiles for each of the mummies they studied.
"For mummies, this is the first time that this has been achieved and this is building on recent technological advances in the forensic sciences. The technology now has become much more powerful than before to identify and analyse minute traces of human tissues or forensic samples." The mummies are not the oldest corpses to come under the geneticists' microscope, but they are perhaps the least convenient, said Prof Gad. Most ancient human bodies from which scientists have taken such thorough genetic data were neatly encased in ice for millennia before they were discovered.
Not so for the dead inhabitants of Egypt's dusty deserts. To examine the mummies, scientists had to confront the "mixed blessing" of ancient embalming techniques, said Prof Gad. While ancient Egyptian priests were able to chemically preserve human tissue for thousands of years, their methods left genetic material damaged and compromised. In order to isolate the mummies' DNA - the nucleic acids that form the unique blueprints for all living organisms - geneticists had to separate the ancient preservative resins from their tissue samples.
Prof Gad declined to describe how his team separated the resins because the methods are pending publication in peer-reviewed journals. But after millennia of gradual decay and the recent removal of toxic embalming fluids, the Egyptian and German scientists were left with only tiny genetic samples, analysis of which would not have been possible without recent technological advances, said Carsten Pusch, a geneticist at Germany's University of Tübingen.
These days, most genetic testing is all but routine, said Dr Pusch, who likened the procedure to cooking a meal with the help of a recipe. But the small sample sizes from ancient mummies meant that the biologists had to improvise. Conventional genetic studies of the sort used in paternity tests and crime labs typically "amplify" or duplicate a given genetic sample using a process known as polymerase chain reaction (PCR). Innovations in PCR technology allowed Dr Pusch and his team to isolate tiny fragments of undamaged genetic material in the mummies and duplicate them to a level that was suitable for conventional genetic testing.
"There is no comparable work available. There was nothing that we could go and cross-check with other colleagues, talk to them and combine our experiences. We were left alone," Dr Pusch said, adding that he warned his team members that their two years of labour might yield little to no workable data. "This is indeed some kind of pioneering work. I know everybody likes to use phrases like this because it sounds great, but in this case it's definitely true."
Published: February 18, 2010 04:00 AM