FGF23 and chronic kidney disease: For instance, polymorphisms in fibroblast growth factor 23 (FGF23), a hormone that regulates phosphate and Ca homeostasis, have been related to VC in CKD patients71 Modification effects on the relationship of Mn levels in urine with the risk of dyslexia in children were suggested by rs27072 in the SLC6A3 gene, which may reduce the affinity of the dopamine transporter for Mn, increase the intracellular accumulation of Mn, and thus ultimately modulate its neurotoxic effects.