In a clinical study S. Rotondi et al. investigated whether a soluble form of Klotho could represent a marker of renal damage of CKD- (chronic kidney disease-) MBD (mineral bone disorder), indicative of the cross-talk between bone and kidney, and concluded that soluble Klotho could be considered an early marker of mineral metabolism impairment in renal disease. This evidence concerns the gene KL and Marchiafava-Bignami disease.