Many people think that primary phagocytic syndrome is a genetic problem and that a genetic test will diagnose it, and that if the genetic test does not reveal a problem, it is not primary phagocytic syndrome, but this is wrong. First, primary phagocytic syndrome was initially thought to have 6 genes associated with it, but now it has been expanded to 12 genes. At present, we do not know enough about the primary disease, and there may be some unknown genes that cause primary phagocytic syndrome beyond the 12 genes. Therefore, even if all 12 genes are tested, it is not possible to exclude primary phagocytic syndrome. In addition, the diagnosis of primary phagocytic syndrome after genetic testing requires a very specialized expert to interpret the report in order to reach a relatively correct conclusion, which many doctors do not have the ability to do now. Therefore, when a patient gets the genetic test report, it is best to get it interpreted by a specialist in genetics or a very experienced hematologist. For example, phagocytic syndrome is currently considered to be a recessive disorder, and all people have one sex chromosome from their father and one from their mother. In phagocytic syndrome, the diagnosis of primary phagocytic syndrome is made when both sex chromosomes are detected as faulty. When only the chromosome from the father is detected to be faulty and the chromosome from the mother is normal, can the diagnosis of this primary disease be made? Previously, it was thought not, but recently many foreign publications have reported that this condition can be diagnosed. Because this phenomenon is a heterozygous mutation, it can be diagnosed as primary phagocytic syndrome by testing the gene protein function, and by doing tests such as NK cell activity test and CD107. Moreover, it has been confirmed abroad from molecular biology protein function as well as signal of protein function transmission that primary phagocytic syndrome occurs when the above heterozygous mutation occurs. Therefore, it cannot be easily determined whether the disease is primary or not after doing genetic testing.