This chapter sheds light on hepcidin, historical view of hepcidin, and the time of its discovery in the first section. Then this chapter gives information about the genetic aspect and the importance of gene knowledge of hepcidin in explaining many disorders in human beings, supported by illustration figures. The regulation of iron in the human body as an essential function of hepcidin is discussed in this chapter. Examples of the genes of hepcidin (HAMP and HFE) are highlighted in detail as they are essential in regulating iron as well as discussing the genetic mutations that occur in these genes and their medical and clinical impacts for many diseases such as thalassemia. Finally, the inherited disorders related to hepcidin that lead to genetic diseases are discussed.