Beethoven had the hepatitis B virus, as well as a genetic predisposition to cirrhosis, which, added to his high alcohol consumption, explains the liver failure that caused his death at the age of 56 in 1827. This is the conclusion It emerges from the analysis of the genome of five locks of hair attributed to the German composer, carried out by an international scientific team that today presents the results of its eight years of work in the journal Current Biology.

Researchers have not been able to clarify the cause of Beethoven’s deafness, which began in his youth and worsened over the years. Neither of the recurring gastrointestinal problems that afflicted him, although the analysis of his genome rules out that he was celiac and indicates a low probability of inflammatory bowel disease.

But they have discovered that he could have been an illegitimate child, since his Y chromosome is different from that of other men in his family. And that he did not suffer from lead poisoning, as deduced from a previous study of a strand that has turned out to be false.

It was Beethoven himself who asked that his deafness be made public after his death, recall the researchers in Current Biology. This motivated them to apply ancient DNA analysis techniques to eight locks presumably corresponding to the composer.

Five of them are from the same man, with ancestors from the same regions as Beethoven’s family, and with a level of DNA degradation that indicates they date back about two hundred years. This, together with the known details about the origin of the locks, “indicates that they are authentic with almost complete certainty,” Tristan Begg, first author of the work, from the Max Planck Institute for Evolutionary Anthropology in Leipzig, declared yesterday at a press conference. (Germany) and the University of Cambridge (United Kingdom).

Analysis of two other locks has not been able to confirm that they are authentic.

The one that is surely false is Hiller’s lock, the most famous of those attributed to Beethoven, which the young musician Ferdinand Hiller supposedly cut off after the maestro’s death and which, after an eventful story, ended up being sold for $7,300 in a auction at Sotheby’s in 1994. It has turned out to have two X chromosomes, indicating that it belongs to a woman.

The analysis of the locks considered authentic has revealed that Beethoven had the genetic alteration that most increases the risk of developing cirrhosis, located in the PNPLA3 gene. He had inherited this alteration from both his father and his mother, so he had it repeated in both copies of the gene.

In addition, the hepatitis B virus genome has been found in the so-called Stumpff lock, the one with the best preserved DNA of the five and which was cut shortly after the musician’s death. “Since the hair grows from the scalp, it means that he had the infection shortly before he died,” Johannes Krause, lead researcher on the project, from the Max Planck Institute for Evolutionary Anthropology, told the news conference.

The research does not clarify when Beethoven contracted hepatitis, but the fact that he suffered a first episode of jaundice in the summer of 1821 indicates that it may have been around this time, when he was 50 years old.

The genome does not provide new data on how much alcohol Beethoven drank. His conversation books – which he kept so he could have a written dialogue with his friends – indicate that “his alcohol consumption was very constant, although it is difficult to estimate the amount,” according to Tristan Begg. “It was probably an amount of alcohol that we know today is harmful to the liver.”

“We think that the liver disease that led to his death was the product of a combination of his genetic predisposition, his well-documented alcohol use, and hepatitis B,” said Markus Nöthen, co-author of the research.

Regarding the cause of his deafness, no genetic alteration has been found that could explain it. The hypotheses that it could be due to otosclerosis (a disease that affects the bones of the middle ear) or Paget’s disease (which also affects the bones) have not been confirmed or refuted. “We have only been able to sequence two-thirds of her genome with a high level of reliability; we cannot make any definitive statements at this time,” Begg explained. Beethoven’s genome data will be made publicly available so that if more deafness-related genetic alterations are discovered in the future, it can be checked whether she had any of them.

The most surprising result of the investigation is that the composer’s Y chromosome is different from that of five other men in the Beethoven family who have volunteered to participate in the project. All of them are descendants of Aert van Beethoven (1535-1609), who had four sons and one daughter. This means that, sometime between the late 16th century and Ludwig’s birth in 1770, a man from outside the Beethoven family introduced his Y chromosome into the family.

“If we know that there has been an out-of-pair event at some point in the seven generations before Beethoven, we cannot rule out that Beethoven himself was illegitimate,” Begg stated. “We are not saying that it was; We are just saying that it is a possibility that must be considered.”