The goal of this observational study is to learn and assess muscle morphological and electromechanical properties in patients affected with Marfan syndrome (MFS) and Ehlers Danlos syndrome (EDS). the main questions it aims to answer are:

• To assess the ability to develop muscle strength;
• Muscle and tendon morphology involved in muscle contractions/relaxation;
• Neuromuscular functionality.

Participants will be take part in the study by performing a test for the assessment of the neuromuscular activity (voluntary muscle contractions) and undergoing a muscle ultrasound for the study of muscles and tendons.

Researchers will compare the two groups with a control group to see potential differences in the morphological and neuromuscular structures of syndromic patients.

MFS, with an autosomal dominant inheritance, can lead to the presence of pathological systemic/syndromic phenotypes. Despite the cardiovascular involvement is responsible for the high mortality and morbidity, the skeletal system and the muscular system also present alterations at the metabolic level.

Like MFS, Ehlers-Danlos Syndrome (EDS) is a rare autosomal dominantly inherited connective tissue disorder. EDS is caused by mutations that cause impaired collagen production, therefore of pathological phenotypes affecting connective tissues such as the integumentary system, the system skeletal system, the cardiovascular system and other organs and tissues. Joint dislocations, musculoskeletal pain, atrophic scarring, and severe scoliosis may occur in patients with EDS.

To date, there are no studies in literature assessing neuromuscular properties in patients with MFS and EDS.

However, the analysis of the musculo-tendon morphological and mechanical properties makes it possible to evaluate the muscle capacity especially in pathological conditions, where the morphology and tendon mechanics are altered, thus providing pivotal information on changes in the contractile capacity of the muscle.

Inclusion Criteria:

• Diagnosis of Marfan syndrome or Ehlers Danlos syndrome currently in follow-up at Cardiovascular Genetic Centre IRCCS Policlinico San Donato;
• Signed informed consent;

Exclusion Criteria:

• Previous muscle-tendon injuries in the lower and/or upper limbs;
• Presence of cardiac pacemaker;
• Epilepsia;
• Presence neurological disorders or circulatory diseases in the lower limbs;
• Pregnancy.

Primary care clinic