The main aim of this study is to evaluate the effect of cross linking on the elasticity of skin samples from patients with non-vascular Ehlers-Danlos Syndrome (hEDS or cEDS).

This is a single-center study based on skin biopsies. The skin biopsies will be taken at the non-vascular Ehlers-Danlos syndromes reference center at the Raymond Poincaré Hospital (Garches), by Dr. Karelle Benistan. This center regularly performs this type of biopsy as part of its routine care, and has set up a fibroblast bank for Genethon (Authorization for biological collection at Genethon: SED BACG n° DC-2021-4628).

Samples will be transported to the Centre de Recherche Saint-Antoine (UMR-S 938) where they will be processed, cut and placed on histological slides.

Atomic force microscopy analyses will be carried out at the Laboratoire de Réactivité de Surface (CNRS/Sorbonne University).

Inclusion Criteria:

• Patient aged 18 or over, having read and signed the consent form for participation in the study
• Patient with classic or hypermobile Ehlers-Danlos syndrome
• Regularly followed-up at the non-vascular Ehlers-Danlos Syndrome Reference Center at Garches Hospital.

Exclusion Criteria:

• Patient under court protection, guardianship or curatorship
• Pregnant or breast-feeding patient
• Patient not affiliated to the French social security system
• Impossibility of giving the subject informed information and/or written informed consent: dementia, psychosis, disturbed consciousness, non-French-speaking patient
• Contraindication to anaesthesia or allergy to local anaesthetic product