Effective safety system and risk anticipation
The Genetic Disease National Observatory

 Constantly improving the health quality of disseminated genetic profiles

Genetic diseases (gene mutations, chromosome anomalies) are natural risks involved in gene recombination at fertilization. These anomalies cause developmental disorders or diseases. Every population harbours genetic diseases. They are usually extremely rare, which makes them difficult to detect and explains why they generally go unnoticed.

While massive use of a few elite studs via insemination makes it possible to disseminate significant genetic improvements, it can also contribute to the rapid spreading of such genetic diseases within a population. The economic consequences for livestock breeders and sub-sectors can be tremendous.

Analyzing the genetic history of some breeds clearly demonstrates this is not just a theoretical risk. In the 1990s, the Holstein breed went through 2 fairly serious crises linked with the dissemination of genetic diseases (BLAD and CVM in the progeny of the US bulls Osborndale-Ivanhoe and Bell).

 A specific national epidemiological surveillance system

The first observation stages of appearance, clinical characterization and sampling of genetic diseases are the most difficult to implement as they require substantial coordination and the field-intervention of a variety of actors.

To control and block dissemination, the actors involved in French selection programmes decided to set up a national epidemiological surveillance system at the beginning of the 2000s in order to provide early detection and descriptions of genetic diseases, as well as to discover their genetic determinants.

Since 2002, this specific epidemiological surveillance is managed by the National Genetic Disease Observatory, under the aegis of the INRA [French national institute for agronomics research] and the Institut de l’Elevage, which work closely with the UNCEIA [French national federation of selection-industry businesses], Races de France [French breeds association], the Ministry for Agriculture, the SNGTV [French national society of technical veterinary groups], and more recently with veterinary schools.

 Efficiency boosted by genotyping

The operation of the national genetic disease observatory is first and foremost based on having sub-sector actors (genetic consultants, artificial insemination technicians, livestock breeders, veterinarians, etc.) provide statements and phenotype descriptions for any physical anomaly observed either at birth or later in life.

The analysis of thousands of statement records in the national database makes it possible to begin by specifying the seriousness and dissemination level of each detected anomaly.

For the cases that are most frequent and have the highest impact, research programmes relying on genotyping the specimens involved make it possible to confirm or infirm the genetic determination of the disease. Genomics tools have made substantial progress over the last few years and now enable geneticists to isolate the problem gene with growing rapidity.

A diagnostic DNA test that makes it possible to differentiate sick specimens, carriers and non-carriers, is the only effective tool in a proactive policy aimed at eradicating diseases within a population. If necessary, carrier bulls are then prematurely removed from selection programmes.

In order to continue and improve on the efforts made, a new phase of development of the observatory’s national information system was launched in 2010. It will ultimately enable the overhaul of the national database, statement recording via the internet, the opening of a photographic library to provide visuals of anomalies, etc.