COSY is a joint initiative of 11 partners and one patient association. It combines all the necessary skills to propose innovative tools in physiopathology, genetics, imaging and care reorganization.

Conjointly, we aim to re-define a new standard of care and to offer a unique multidisciplinary service organization dedicated to OS patients.


This work package will coordinate the entire project for all aspects of management and logistics. It will ensure that the project reaches its objectives and expected impacts and guarantee compliance with regulatory requirements.

Lead: Institut du cerveau (ICM)

Focused on genetic, this WP aims to develop a highly-sensitive sequencing gene panel in to identify mutations in genes belonging to the PIK3CA/AKT/mTOR pathway and identify new causative genes in the panel-negative patients using whole exome sequencing (WES). Finally, it will create in vitro functional assays to test the pathogenicity of novel variants.


This WP aims to decipher the physiopathology of these syndromes to offer precision and personalized medicine. On that account, WP3 will develop appropriate animal models, in addition to mutant PIK3CA tissue specific models, test novel pharmacological treatments in an approach of personalized medicine depending on the mutated gene, and unravel the molecular signature and putative biomarkers of OS by complementing the human data and animal models with in vitro analysis of cell lines.

Lead : Assistance publique – Hopitaux (AP-HP)

Describing the natural course of the disease is crucial to identify optimal disease management strategies. With the aim of doing so, this WP will be committed in creating a national registry, standardizing the medical care for OS patients, developing a biobank, and, finally, doing the follow up of PIK3CA-Related Overgrowth Syndrome patients treated with PIK3CA inhibitor (BYL719) under compassionate use program.

Lead : AP-HP

The overall objective is the reorganization of healthcare for OS patients in France. Thus, WP5 will be responsible for the creation of 4 multidisciplinary expert centers in France, for the dissemination of the standard of care for OS patients, established in WP4, and for the creation of a website dedicated to OS patients that will allow OS patients to have access to physicians and the exchange of medical information between patients and doctors.

Lead: Hospices Civils de Lyon – HCL

In order to transform the radiological diagnosis and follow up of OS patients, WP6 will comprises:

  • Standardization of radiological care for OS patients;
  • A complete description of the radiological natural history of OS (including brain plus other tissues) but also during treatment
  • An easy and new visualization tool to explore the composition, volume and shape of the malformations;
  • A new tool to explore and follow bone composition and deformation but also soft tissue composition and creating a 3D personalized virtual patient.

Lead: AP-HP

Overall, WP7 will be dedicated to the economical evaluation of the project and social improvement. To achieve this, WP7 will conduct a cost evaluation of the project and comparison with the current cost of cares will be conducted, implement strategies to improve the socialization and well-being of OS patients, specifically apply the model developed at Necker-Enfants Malades hospital called “La suite”, and launch a specific Human and Social Sciences (HSS) call to better understand individual, familial and psychosocial consequences of OS.

To ensure effective dissemination of the knowledge generated outside the consortium and manage intellectual property rights and the exploitation of the results, this WP will create and maintain a public website for informing the public of COSY activities, establish contact to relevant press and media channels, increase knowledge of relevant stakeholders and the scientific community, define a product development plan and a commercial strategy, and finally protect the results with appropriate IP strategy, and sequence the events of protection and publication.