Every human being has a unique DNA “fingerprint”. In other words, the genetic material of any two individuals can be clearly distinguished. Computational biologists at the Technical University of Munich (TUM) have now determined that the impact of these variations has been greatly underestimated. The new insights could importantly impact advances in personalized medicine.
Proteins are the machinery of life. Without them, no cell can function. About 20,000 different proteins are responsible for metabolism, growth and regeneration in the human body. The building blocks of proteins are the amino acids. These are assembled in the cell according to a defined blueprint contained in DNA.
An extensive study in which blood samples of 60,000 people were examined has shown that surprisingly wide variations exist between the proteins of healthy individuals: In two non-related individuals, on average 20,000 building blocks — i.e. amino acids — have differences known as SAVs (single amino acid variants). The MacArthur Lab in the USA has assembled about 10 million of these SAVs.
“Until now, many experts believed most of these variants to have no substantial impact upon protein function,” said Prof. Burkhard Rost, Chair for Bioinformatics and Computational Biology at TUM. This assumption is difficult to prove: Experimental studies cannot be carried out for such an enormous number of SAVs. In fact, relevant experimental data are available for fewer than 0.01 percent of the SAVs.
The TUM researchers have therefore developed a method that enables predicting the effects of the SAVs through computer simulations. Using data obtained in laboratory experiments, a program predicts the probable effect for the 99.99 percent of the SAVs about which nothing is known. “Along with statistical methods, we use artificial intelligence, and in particular machine learning and neural networks. That enables us to create models,” explained Yannick Mahlich, lead author of the study.