Alexander Gardner via Wikimedia Commons // Public Domain
Alexander Gardner via Wikimedia Commons // Public Domain

Did Abraham Lincoln Have a Genetic Mutation?

Alexander Gardner via Wikimedia Commons // Public Domain
Alexander Gardner via Wikimedia Commons // Public Domain

Abraham Lincoln's life has provided material for scores of historians. But one aspect of his history is being investigated by a very different kind of expert: geneticists. Lincoln’s appearance and medical history have some convinced that he had a condition called Marfan syndrome.

Marfan syndrome is one of a family of connective tissue disorders—that is, conditions that affect the glue that holds the body together. It affects many body systems and can be quite serious, but its most obvious signs are external: an unusually tall, lanky stature; and long limbs, hands, and feet—and if that doesn’t describe Abraham Lincoln, nothing does. 

The condition affects about 1 in every 5000 people, but because the syndrome is frequently inherited, many of the people who have it are related. And when one person is diagnosed, physicians frequently start looking at that person’s ancestry. Such was the case of a 7-year-old boy diagnosed in 1964. The diagnosing physician, a man named Harold Schwartz, had traced his patient’s family tree back more than 200 years, all the way to Mordecai Lincoln II, Abraham’s great-great-grandfather. 

Two years before Schwartz’s discovery, a doctor named A.M. Gordon developed a similar theory, which he published in the Journal of the American Medical Association. Schwartz added his new evidence to the academic literature, and the debate began in earnest.

Opponents of the theory argued that Lincoln had never shown any other symptoms of the condition. He had no heart problems, no lung issues, no eye trouble, and no overtly loose joints. He was 56 years old when he was assassinated, which would have been a pretty decent lifespan for anyone in those days. (Medicine has made great progress in its investigation of Marfan syndrome since Lincoln’s day. While there is no cure, the syndrome is treatable, and people who have it can expect to lead long, full lives.) And besides, the nay-sayers said, if Lincoln inherited the condition from his paternal great-grandfather, how do we account for his mother's looks?

This artist may have taken the resemblance a little too far. Painting by Lloyd Ostendorf via Wikimedia Commons // Public Domain

By most accounts, Nancy Hanks Lincoln was the spitting image of her son, with long limbs and a sad, melancholic face. A minister who was a friend of the family described her as “quite tall…bony, angular, lean…She had long arms, large head, with the forehead exceedingly broad … with chest sunken.” Nancy died at the age of 34, either from “milk sickness” or “wasting disease,” depending on which records you read. Whether there were other elements involved in her death, we’ll likely never know.

Her son is another story. Scientists discovered the gene associated with the condition in the 1990s, which suggested to them that genetic testing was possible, as long as you had a sample of someone’s DNA.

As it so happens, we’ve got that. Historians have preserved a number of grisly artifacts from the night of Lincoln’s assassination, including locks of hair, skull fragments, and even his blood, which soaked into his surgeon’s shirt sleeves.

Once scientists realized that they could potentially test the former president's DNA, a second question arose: Should they? In the 1990s, the National Museum of Health and Medicine created a committee of geneticists, lawyers, and forensic scientists, and left the decision up to them.

Those in favor of proceeding argued that, as an American hero, Lincoln could be a beacon and an inspiration for people living with the condition today. Addressing the committee, one person with Marfan syndrome said, “The fact that Lincoln may have had Marfan syndrome shows those of us that we too can contribute something of value to society … It’s time that all people, especially medical ethicists, realize that having the Marfan syndrome is not shameful, it’s just darned inconvenient.”

Those against emphasized how private Lincoln was in life, and stressed that to conduct medical tests on him without his consent would be a huge invasion of that privacy.

The committee eventually decided that, had he been alive, Abraham Lincoln would have consented to testing if the results could have helped other people. Unfortunately, their decision was moot. Additional Marfan-related genes had been discovered during their deliberations, and a definitive diagnosis would not really be possible.

Did Abe Lincoln have Marfan syndrome? We still don’t know for sure. But even without an answer, the debate about Abraham Lincoln’s appearance continues to raise public awareness of a condition affecting thousands of Americans.

Tony Karumba, AFP/Getty Images
The World's Last Male Northern White Rhino Has Died, But Could He Still Help Save the Species?
Tony Karumba, AFP/Getty Images
Tony Karumba, AFP/Getty Images

Following age-related complications, Sudan the northern white rhinoceros was euthanized by a team of vets in Kenya at 45 years old, CNN reports. He was one of only three northern white rhinos left on earth and the last male of his subspecies. For years, Sudan had represented the final hope for the survival of his kind, but now scientists have a back-up plan: Using Sudan's sperm, they may be able to continue his genetic line even after his death.

Northern white rhino numbers dwindled from 2000 in 1960 to only three in recent years. Those last survivors, Sudan, his daughter Najin, and granddaughter Fatu, lived together at the Ol Pejeta Conservancy in Kenya. Each animal had physical issues making it difficult for them to breed, and now with Sudan gone, a new generation of northern white rhinos looks even less likely.

But there is one way the story of these animals doesn't end in extinction. Before Sudan died, researchers were able to save some of his genetic material, which means it's still possible for him to father offspring. Scientists may either use the sperm to artificially inseminate one of the surviving females (even though they're related) or, due to their age and ailments, fertilize one of their eggs and implant the embryo into a female of a similar subspecies, like the southern white rhino, using in vitro fertilization.

"We must take advantage of the unique situation in which cellular technologies are utilized for conservation of critically endangered species," Jan Stejskal, an official at the Dvur Kralove Zoo in the Czech Republic where Sudan lived until 2009, told AFP. "It may sound unbelievable, but thanks to the newly developed techniques even Sudan could still have an offspring."

Poaching has been a major contributor to the northern white rhino's decline over the past century. Rhinos are often hunted for their horns, which are believed to have medicinal properties in some Asian cultures. (Other people just view the horn as a sign of wealth and status.) Procreating is the biggest issue threatening the northern white rhinoceros at the moment. If such poaching continues, other rhino species in the wild could end up in the same situation.

[h/t CNN]

A Year in Space Changed How Astronaut Scott Kelly's Genes Behaved

After spending 342 consecutive days onboard the International Space Station from 2015 to 2016, astronaut Scott Kelly now holds the record for longest single space mission by an American. But his "One-Year" study with NASA was about more than breaking records: Its purpose was to show how prolonged time in orbit would effect Kelly's genetic makeup compared to that of his identical twin brother on Earth. Now, following recent evaluations of the two men, it appears that Scott Kelly's gene expression was significantly altered by his time in space, reports.

NASA announced the most recent findings from its Twins Study ahead of a more comprehensive paper combining the work of multiple teams of researchers that is slated for later in 2018. Like his brother Scott, Mark is also an astronaut, making the pair the only twin astronauts in history. So when NASA was looking for a way to study the long-term effects of space life, the siblings were a perfect fit.

As Scott was sending tweets and blowing bubbles on the ISS, Mark stayed on Earth to serve as the control. Biological samples taken from both subjects before, during, and after the space flight showed some dramatic differences. According to an investigation conducted by Susan Bailey of Colorado State University, Scott's telomeres, the protective "cap" at the ends of chromosomes that shorten as we age, got longer in space. The telomeres began shrinking back to preflight levels, however, a few days after Scott's return to Earth. Scott was subjected to regular exercise and a restricted diet aboard the ISS, so the new lifestyle may explain the sudden telomere boost.

Other genetic differences stuck around even months after landing. "Although 93 percent of genes' expression returned to normal post-flight, a subset of several hundred 'space genes' were still disrupted after return to Earth," acccording to a NASA press release. About 7 percent of Scott's genes may show longer-term changes, included the genes associated with DNA repair, immune health, bone formation, hypoxia (an oxygen deficiency in the tissues) and hypercapnia (excessive carbon dioxide in the bloodstream).

A long list of factors, like radiation, caloric restriction, and zero gravity, may have contributed to the results. NASA plans to use these findings to develop countermeasures against these effects, which will be essential if the agency plans to send humans to Mars, a journey that could take three times as long as Scott Kelly's ISS mission.


Editor's note: We updated the headline and one line of this story to more accurately reflect the research findings. We apologize for the error. 


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