Considering the results of several GWAS, there is strong evidence of genetic regulation of iron metabolism, and mutations in transmembrane serine protease 6 (TMPRSS6) gene that encodes for an enzyme that regulates hepcidin involved in iron homeostasis, iron carrier transferrin (TF), and transferrin receptor-2 (TFR2) genes have been associated with iron deficiency [112]. This evidence concerns the gene TF and nutritional disorder.