With one Ludwig van Beethoven mystery likely solved, it's on to another one: why he spent his life in so much pain. It's a quest that led scientists to sequence his genome in a search for answers as to what may have caused his hearing loss, days-long bouts of diarrhea, and the liver disease that is thought to have killed him; their conclusions were published Wednesday in Current Biology.
NPR gives some historical context, reporting that the composer went so far as to ask his brothers in a 1802 letter to go public with his ailments upon his death; he was in his 30s at the time and died at 56. Tristan Begg, a biological anthropology PhD student at the University of Cambridge, details the challenges of sourcing enough of Beethoven's DNA, which initially hit a dead end when the three locks of hair he had to sequence turned out to come from three different people—with it unclear if any had belonged to Beethoven (one did). It was only later, when additional locks of hair were secured by a member of the American Beethoven Society, that the project came to life: Researchers ended up with five locks that hailed from the same European male and were "almost certainly authentic," per the AP.
Begg didn't find any genetic smoking gun when it came to Beethoven's hearing or GI issues (other than ruling out lactose or gluten intolerance). But a gene called PNPLA3 got Begg's pulse racing. "It would have roughly tripled his risk for developing the full spectrum of liver disease," says Begg, particularly if he was a chronic drinker as Beethoven was described as having been. Begg also found DNA from the hepatitis B virus—possibly transmitted to him at birth—which is a main cause of cirrhosis and liver cancer. Combined, they would have made things worse. "Whichever way you cut it, it really comes as no surprise he died of cirrhosis," Begg says.
But on top of the mystery, the researchers uncovered a secret: When they tested DNA from living "van Beethovens," scientists discovered the Y chromosomes (those passed down from the father's side) from the five men matched each other, but not the composer. This suggests there was an "extra-pair paternity event" (aka, an extramarital affair that produced a child) prior to Beethoven's birth. The New York Times speaks with study co-author Maarten Larmuseau, whose theory is that Beethoven's father was born to the composer’s grandmother via a man other than his grandfather. Larmuseau notes there are no records of Beethoven’s father having been baptized, and his grandfather and father had a strained relationship. (Read more Beethoven stories.)