At the beginning of the 19th century, specifically on March 27, 1827, two of the companions of the famous German composer Ludwig van Beethoven discovered the day after his death a moving letter he wrote in 1802 to his brothers, in which he admitted that he suffers from a gradual loss of hearing and that his condition is hopeless, and if it were not for his art and that he still has a lot to offer to commit suicide, Beethoven asked his personal doctor, Dr. Johann Adam Schmidt, to announce the details of his illness to the public after his death.

Since then, Beethoven's health has been debated among scientists. Previously, researchers relied mainly on documentary sources including Beethoven's letters, memoirs, conversation books, doctors' notes, and an autopsy report, but no one had ever touched on genetic research to explain the causes of his illness.

An international team that included researchers from the University of Cambridge, the Beethoven Center in San Jose, the Beethoven Society, the University Hospital Bonn, and the Max Planck Institute for Evolutionary Anthropology conducted research revealing important information about Beethoven's health and cause of death, and published their findings in the journal Current Biology on March 22.

Tufts of Beethoven's hair sent to pianist Johann Andreas Stumf (Fizz.org)

Genetic analysis of Beethoven's hair strands

The researchers extensively analyzed Beethoven's genome from "native" strands of hair dating back to the last 7 years of his life and genetically identical to his ancestors to determine the causes of his disease and whether his genes were responsible for it.

The researchers studied 8 strands of hair said to belong to Beethoven, known by the names of those who received them from Beethoven in his lifetime as a souvenir: Müller, Berman, Halm Thayer, Mochels, Stumpf, Kramoulini Braun, Heller and Kessler. The researchers obtained these strands for study from public and private collections in the UK, Europe and the US.

The researchers have established that there are only 5 original strands, the most important of which is a strand that Beethoven sent to pianist Johann Andreas Stumf with a letter, where the strand was well preserved and genetically corresponded to living people and shared with Beethoven's origins.

On the other hand, the surprise was that the famous "Heller" strand, which was previously thought to belong to Beethoven, turned out to be a non-original strand belonging to a woman and not to the musician, and it was contaminated with lead, which led scientists to believe that Beethoven had lead poisoning, and that all his pain he suffered because of it.

Heller's strand that the researchers discovered belonged to a woman, not Beethoven (San Jose State University)

Beethoven's genetic predisposition to diseases

It is known that Beethoven suffered in his mid-twenties from a gradual loss of hearing, until he ended up suffering from deafness in 1818, but what many do not know is that he was suffering from excruciating intestinal pain, and he was exposed to two episodes of jaundice, a yellowing of the skin and eyes and is considered evidence of an acute liver disease that peaked months before his death at the age of 56 years.

The results of the research revealed that Beethoven was genetically predisposed to liver disease, and with regular drinking he developed cirrhosis of the liver, which led to a deterioration in his health, and this is a sufficient explanation for his acute liver disease.

On the other hand, the researchers were able to prove that Beethoven had hepatitis B virus infection, but it was not clear whether the disease was chronic, i.e. contracted at a young age (passed on from his mother during childbirth) or contracted as a result of a recent infection due to surgery or sexual contact.

Tristan Begg, first author of the study and a researcher at the University of Cambridge, said in a press release: "We have concluded from the conversation books Beethoven used during the last decade of his life - so that his friends and acquaintances could write down their side of the conversation - that he drank regularly, and although it was difficult to estimate the amounts he consumed, most of his contemporaries claimed that his consumption was moderate by the standards of the time. But now, his alcohol consumption was heavy and had the biggest impact on his liver."

The genome did not reveal the reason for Beethoven's design, but science is in rapid development and could one day reveal it (Associated Press)

Causes of Beethoven's deafness

Despite the great advances in medical genetics, the genetic causes of many diseases are not fully understood, especially in the case of multi-cause diseases, which combine genetic causes, and non-genetic causes that may contribute significantly to the development of the disease, and here the matter becomes more complicated, so researchers have not found a genetic cause responsible for Beethoven's hearing loss.

Dr Axel Schmidt, from the Institute of Human Genetics at the University Hospital Bonn, said: "Although we have not been able to discover the causes of Beethoven's deafness, genomics is rapidly evolving, and in the future we can identify those causes."

Similar to the results of hearing loss, the researchers found no genetic explanation for Beethoven's complaints about his stomach. However, they were able to refute the validity of some previous diagnoses, for example, ruling out the possibility that his stomach is lactose intolerant or has irritable bowel syndrome.

Johannes Krauss, a researcher at the Max Planck Institute for Evolutionary Anthropology, said: "We can't say for sure what caused Beethoven's death, but we can now confirm his genetic predisposition to liver disease and hepatitis B virus."

The study's first author, a researcher at the University of Cambridge, hopes that making Beethoven's genome sequenced available to researchers will one day answer remaining questions about the musician's health.