Chronic Kidney Disease : Role of Biological Factors and Apolipoprotein L1 Encoding Gene (APOL1)

Inclusion Criteria: * Patients 18 y and older, of both sexes, Afro Caribbeans * Living in Guadeloupe * Having been informed of objectives and constraints of the study and who have given their written consent. * For patients with CKD : at stage 4 (GFR \< than 30 ml / min / 1.73m2.), whatever the etiology of CKD, associated pathologies and treatments, * For patients with normal renal function : serum creatinine \< 10 mg/l. Exclusion Criteria: * Patients 18 y and older, of both sexes, Afro Caribbeans * Living in Guadeloupe * Having been informed of objectives and constraints of the study and who have given their written consent. * For patients with CKD : at stage 4 (GFR \< than 30 ml / min / 1.73m2.), whatever the etiology of CKD, associated pathologies and treatments, * For patients with normal renal function : serum creatinine \< 10 mg/l.