This narrative review aims to give an overview of the genetic basis, linked with melanoma development, of alterations in STX17, ASIP and MITF genes, a description of the clinical and pathological differences between naevus, dermal melanoma, dermal melanomatosis and anaplastic malignant melanoma, as well as a description of the role of the different diagnostic tools, mainly fine needle aspiration, histopathology and immunohistochemistry. The gene discussed is STX17; the disease is melanoma.