Inclusion Criteria:  Patient aged 18 years or older Male or female patient Patient followed in the investigating department for familial NEM2A C634R (multiple endocrine neoplasia type 2) with or without pheochromocytoma Patient affiliated to or benefiting from a social security scheme Patient having given his non-opposition to participate in this study Patient who has given his consent for the genetic analysis carried out in the framework of the study Patient able to understand the purpose of the study  Exclusion Criteria:  Protected persons (articles L1121-5, L1121-6 and L121-8 of the Public Health Code): pregnant or breastfeeding women, persons deprived of their liberty, under guardianship or curator Patients unable to understand the purpose of the study and the information note