Nuovo S, Fuiano L, Micalizzi A, et al. - Researchers investigated a biomarker able to quantify the risk of progressive chronic kidney disease (CKD) among young children suffering from Joubert syndrome (JS). This study involved 93 Italian patients, in whom renal features were analyzed, including biochemical tests, ultrasound and 1-deamino-8D-arginine vasopressin test among children with decreased basal urine osmolality. Experts observed a subset of patients over time. They reported a rise in CKD frequency with age in patients with JS, and the observed frequency of CKD in these patients was higher than earlier documented. Experts concluded urine osmolality as an early sensitive quantitative biomarker of the risk of progression of CKD.