There are also studies that have not found a correlation between BMIs and disease progression, but they may suggest therapeutic effects, especially effective control of bone destruction.18 Previous studies have confirmed that the levels of tPINP, β-CTX and β-CTX/tPINP ratio were significantly decreased in patients with MBD when treatment was effective.19 This evidence concerns the gene CYP27A1 and Marchiafava-Bignami disease.