All the information required to build every component of our body is carried by the DNA, a complex structure that is present in the cells of any living organisms. The DNA regions that control the formation of each specific element are called genes. In a human cell, there are approximately 30-35000 genes. If all the DNA of a single human cell were laid out in a linear fashion, it would reach 2 metres. However, cells are tiny and so the DNA has to be compacted in special units that are called chromosomes.
The majority of the genes usually carry a complete correct set of information. In some cases, however, errors can occur, which can results in severe diseases, collectively called genetic syndromes. Many of these have been well characterised, and the responsible faulty gene has been identified. The aim of our project is to introduce a functioning version of the faulty gene into cells that are grown in the laboratory, to correct the genetic problem. To do this we used a specialised system, based on the construction of artificial chromosomes. These are similar in structure and behaviour to the normal chromosomes that the cell already possess, but are composed of DNA elements that we choose. We have obtained artificial chromosomes in several different cell types (lung, kidney and brain derived), and we are now attempting to obtain them in stem cells. Stem cells are special cells that can be transformed into any specific cell type, and thus are especially interesting in view of the treatment of genetic syndromes.