Genes

Genes are the carriers of characteristics. What does this mean, and why is genetic research so important with regard to COPD?

With the regularity of a clock, the media report on the discovery of the gene for disease X or condition Y. This is consistently followed by the announcement that that particular discovery brings a cure or at least better treatment of the disease within arm’s reach. However, what is a gene, actually, and what do genes have to do with disease and how can the discovery of a gene help cure disease?

Genes are the carriers of genetic characteristics: hair colour and blood type are examples. Such characteristics occur because the body’s cells contain proteins that determine different characteristics.

Proteins are important substances in every living cell. Not only do they provide shape and solidity, they are also the tool of the cell with which it can exercise its tasks. Proteins determine the characteristics of a cell and, therefore, of the entire organism as well. New proteins are constantly being produced in every cell: in order to replace ‘worn out’ proteins, or because there is a (temporary) need for extra proteins.

The information on how proteins must be produced is recorded in the DNA, the hereditary material that is present in every cell. This DNA consists of two strings that are intertwined. Each string has a length of approximately two metres and consists of some three billion building blocks. The sequence in which these are situated after each other in the DNA is the key to the production of all the different proteins.

The DNA is comprised of four different types of building blocks. A set of three building blocks forms the code for one part of a protein. A single protein consists of a few dozen up to hundreds of parts linked in a chain.

The building blocks, which together contain the entire ‘recipe’ for the production of one protein, form a gene. In total human DNA is estimated to comprise some 30,000 different genes. In each cell, only those genes are used for proteins that are needed in the cell at that moment.

Differences in characteristics (such as blood groups) occur when a gene exists in several forms. One form of the gene contains the recipe for blood group A, the other the recipe for blood group B.

(Hereditary) diseases can occur if the sequence of the DNA building blocks within a gene begins to deviate, for example due to radiation or the effects of harmful substances. Building blocks are located in the wrong place, incorrect building blocks can be built into the gene, ordisappear from it. Because of these errors, the proteins are produced too long, too short, or not at all. Subsequently, the cells lack a properly functioning protein, they go off track, as it were, and a disease can occur.

By investigating which errors in genes are responsible for the occurrence of a certain disease, we can obtain important information about the disease and its possible treatment. If we know which gene contains an error, we can determine which protein deviates and how this can be corrected.

The COPACETIC study is attempting to track down as many genetic errors as possible that are significant to the occurrence of COPD. The more of these that become known, the more possible it will be to predict how susceptible someone is to the harmful effects of smoking and will therefore suffer from COPD. Research into the deviant function of proteins can, in addition, yield more knowledge about what goes wrong in the cells of the lungs when COPD occurs.