The Defidiag Program

The DEFIDIAG Program takes place in a larger and more ambitious national initiative: The French Genomic Medicine 2025 Plan. This plan aims to construct a medical and industrial system to introduce genomic medicine into the care pathway and develop a national framework in this matter.

The France Genomic Medicine 2025 Plan

The France Genomic Medicine 2025 plan, released on June 22, 2016, aims to integrate genome sequencing routinely into clinical practice, as well as to develop a national genomic medicine sector in partnership with research and industry.

Genomic medicine: what are the issues?

  Genomic medicine is transforming the way in which disease progression is prevented, diagnosed, cured and prognostic. The stakes attached to it are therefore major. The entire medical field will in the future be impacted by sequencing the genome. Today, the two major classes of diseases already benefiting from these advances and immediately justifying the deployment of very high-level sequencing capabilities are rare diseases, which are in the majority of genetic diseases, and cancers, which correspond to to somatic genetic diseases, that is to say, restricted to tumor cells. Gradually, genomic medicine will extend to common diseases, since it makes it possible to consider the identification of individuals at risk who may benefit from preventive measures or to determine the appropriate drug based on the genetic characteristics of the individual, in order to to avoid sometimes serious side effects and to ensure optimal therapeutic efficacy.

France genomic medicine 2025: what goals?

  Given its challenges, genomic medicine is an area where competition between countries is strong. In order to prevent France from being technologically dependent on more advanced countries and to ensure the population has access to genomic medicine throughout France, the France Genomics 2025 plan aims to:  
  • to place France in the leading pack of large countries in the field of genomic medicine, aiming at the export of its know-how and the development of a medical and industrial sector of excellence;
  • implement a genomic care pathway with privileged access, common to all patients affected by cancer, rare disease or common disease (and, in the longer term, in new indications that have been validated).
The ethical dimension of the Plan is of paramount importance: it will make it possible to respond to the many questions raised by citizens and associations about consent for access and use of health data, anonymization of data with respect to data. third parties and the management of unwanted secondary or incidental discoveries.  

Defidiag, a pilot project for rare diseases

Defidiag, for Intellectual Disability Diagnostic, is the rare diseases pilot project of theFrance Genomic Medicine 2025 Plan and focuses on intellectual disability.     Among rare diseases, intellectual disability is the leading cause of consultation in pediatric genetic centers. It is estimated that 1 to 3% of the population is intellectually disabled, which would affect about one million French people.     It is a major cause of diagnostic wandering because hundreds of genes are involved in the pathology, which makes it difficult to identify the causes of the disease, necessary to adapt patient care and receive advice. genetics concerning the potential risks of genetic transmission useful to the whole family.     New molecular tools, such as high-throughput sequencing of the genome, which allows us to read all our genetic material, could lead to a significant improvement in the determination of the genes involved.  

The objectives of the study

  This multidisciplinary project, promoted by Inserm, involves specialists in genetics, epidemiology and medico-economic evaluation. It aims to demonstrate the feasibility of complete genome sequencing, as well as its effectiveness, first-line, in the determination of genes involved in intellectual disability. The results of the use of this new technique will be compared to those of the method currently used, known as the "French reference strategy", which is based on the search for the fragile-X syndrome, the analysis of chromosomes and the study of a group of 44 genes known to be involved in intellectual disability. 1275 patient.e.s as well as their two biological parents, more than 3000 people will participate in the study which will last 30 months.  

Expected benefits for patients and society

  While the reference strategy method results in diagnosis in 20% of patients, professionals hope to achieve a 60% diagnostic yield with full genome sequencing. This will allow more families to know more quickly the causes of the disease, to benefit in a shortened time from appropriate care and perhaps to prevent the occurrence of specific complications. An impact study will assess the reduction of diagnostic research costs and consider the conditions of care and reimbursement of this revolutionary technique for all French people.  

Publications of the DEFIDIAG Study Protocol

Articles describing the Defidiag protocol are published and available for further information.