There are several emerging genetic conditions among adolescents and adults. This chapter deals with few common genetic conditions of the adolescents and adults such as cancer genetics: familial cancer, inborn errors of metabolism, blood group alleles and hematological disorders, genetic hemochromatosis, Huntington\'s disease and metal illnesses. It was found that breast cancer, ovarian cancer, multiple endocrine neoplasia, li-fraumeni syndrome, Tarcot syndrome, familial adenomatous polyposis and familial retinoblastoma have basis in heredity. This chapter also discusses the meaning, genetic causation, clinical manifestation, management including nursing management of the inborn errors of metabolism, hematological disorders (Hemolytic disease of new-born, G 6 PD deficiency disease, hereditary spherocytosis, thalassemia, sickle cell anemia, Black diamond anemia, hemophilia, von willebrand disease, congenital amegakaryocytic thrombocytopenia), genetic hemochromatosis, Huntington\'s disease and mental illness. It is presents the comprehensive therapeutic approaches and nursing managements for the genetic disorders.