Beethoven had the hepatitis B virus, as well as a genetic predisposition to cirrhosis, which, added to the high consumption of alcohol, explains the liver failure that caused his death at the age of 56 in 1827. It is the a conclusion that emerges from the analysis of the genome of five strands of hair attributed to the German composer, carried out by an international scientific team that yesterday presented the results of 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. Nor of his recurrent gastrointestinal problems, although the genome analysis rules out that he was celiac and indicates a low probability of inflammatory bowel disease. But they have discovered that he may have been an illegitimate child, as his Y chromosome is different from that of other men in the family. And that he did not suffer from lead poisoning, as was inferred from a previous study of a flake that turned out to be fake.

It was Beethoven himself who requested that his deafness be made public after his death, researchers remember. This motivated them to analyze the genome of eight flakes presumably corresponding to the composer.

Five of the flakes 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 are about 200 years old. This, together with known details about the origin of the flakes, “indicates that they are authentic with almost total certainty”, Tristan Begg, first author of the work, from the Max Planck Institute for Evolutionary Anthropology in Leipzig and the University of Cambridge.

The analysis of two more flakes has not been able to confirm that they are authentic. What is definitely fake is the Hiller flake, the most famous of those attributed to Beethoven, which the young musician Ferdinand Hiller supposedly carved after the master’s death and which, after a turbulent history, ended up being sold for $7,300 at auction at Sotheby’s in 1994. It turned out to have two X chromosomes, indicating that it is female.

The analysis of the five authentic flakes revealed that Beethoven had the genetic alteration that most increases the risk of 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 genome of the hepatitis B virus has been found in the so-called Stumpff flake, the one with the best-preserved DNA of the five, which was cut shortly after the musician’s death. “It means he had the infection shortly before he died,” said Johannes Krause, principal investigator of the project, from the Max Planck Institute for Evolutionary Anthropology. The research does not clarify when Beethoven contracted hepatitis, but the fact that he had a first episode of jaundice in 1821 indicates that it could have been around that time, when he was 50 years old.

The genome does not provide new information about how much alcohol Beethoven drank. His conversation books, which he made to be able to have a written dialogue with his friends, indicate that “his alcohol consumption was very constant, but it is difficult to estimate the amount”, according to Tristan Begg. “We think that the liver disease that led to his death was a product of the combination of his genetic predisposition, his well-documented alcohol consumption and hepatitis B,” said Markus Nöthen, co-author of the research.

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