By: Dr. Gildardo Fco. Zafra de la Rosa.

Before deleterious mutations, the cell has an efficient repair system through the pathway Repair by Homologous Recombination (HRR), which allows you to repair mutations of the double-stranded, by activating a complex molecular mechanism that includes a team of genes, within which are found mainly BRCA1/2, ATM, PALB2, and RAD51; however, when there is a mutation in any of the genes of this pathway, is set to a Deficiency in the Homologous Recombination (HRD).

Defects in the repair occur accumulation of mutations with subsequent malignization cell. It is interesting the fact that these mutations leave molecular signatures, whether they correspond to events in germ cells, as do occur in somatic cells.

When the DNA damage is increased, as occurs in the alterations of the molecular structure, given by rearrangements, deletions/duplications (Indels) or loss of heterozygosity (LOH), it results in genomic instability.

The genomic instability and DNA damage remain in the cell, leaving Scars of the Genome that may be interpreted as indicators of patterns of specific mutations and may be useful as probes, genomic quantitative.

Currently there are programs that use algorithms with ability to analyze, panel sequencing, the origin and evolution of the damage to the DNA.

With these tools not only can ascertain the alterations in the present, but also what happened in the past and infer the prognosis of the patient.