FGF23 and Marchiafava-Bignami disease: Mineral and bone disorders(MBD) including abnormalities of serum calcium (Ca), phosphorus (P), parathyroidhormone (PTH), vitamin D, and fibroblast growth factor 23 (FGF-23), and alsoabnormalities in bone turnover and extra-osseous calcifications contribute to themorbidity and to poor outcomes in these patients3-5.