Renal and Vascular Phenotypic Characterization of Patients With Enamel Renal Syndrome Due to a Pathogenic Variant of the FAM20A Gene and Pathophysiological Study of Ectopic Calcifications

In the research, the investigators will characterize the renal and vascular damage and look for factors favoring the formation of calcification induced by enamel renal syndrome. Patients will undergo four investigations, as part of their routine care, to assess their renal impairment. Each investigation will require a day in the Physiology Department of the George Pompidou European Hospital. The 4 tests are designed to

• precisely measure your renal filtration capacity,
• evaluate your body's calcium and phosphate regulation,
• evaluate your capacity to regulate the elimination of water from the body
• assess your body's ability to regulate "acid" intake. As part of the research, an additional 20 ml blood sample and a urine sample will be taken during the other samples taken as part of routine care. Healthy volunteers will undergo blood and urine tests, dental X-rays and renal ultrasound. For healthy volunteers, the aim of the dental X-ray and renal ultrasound is to check that there are no dental or renal abnormalities, so as to rule out not only email-rein syndrome, but also any dental or renal abnormalities that might resemble it. The aim of blood and urine sampling is to measure various molecules that promote calcification or inhibit the calcification process, so as to be able to compare results obtained in healthy subjects with those obtained in patients with enamel renal syndrome. Each healthy subject will be selected to be matched by age and sex to each of the patients included in the study.