Is primary phagocytic syndrome caused by genetics? It is currently believed that primary phagocytic syndrome is the result of something wrong with the gene itself, and there is a clear genetic correlation. Some people wonder if it is possible that an acquired genetic change could lead to the development of phagocytic syndrome. Theoretically this possibility exists, but there is no clear understanding or diagnosis. In addition, many people wonder if the absence of a family history of the syndrome is not a primary phagocytic syndrome. The answer is no. In fact, consanguineous marriage can lead to primary phagocytic syndrome in the next generation. Because many family members carry faulty genes, when consanguineous marriages occur, pure mutations (i.e., mutations in both alleles of a pair, such as AA or aa type) occur, which means that consanguineous marriages can change heterozygous mutations (mutations in only one of the alleles, such as Aa type) into pure mutations, with the father carrying the faulty gene and the mother carrying the faulty gene, all of which are eventually passed on to the child . As a result, the father, mother, and the rest of the family may not develop the disease, but the child has primary phagocytic syndrome. Therefore, consanguineous marriage is a very important issue in asking about the family history of phagocytic syndrome. We now have two patients in our hematology department who have been diagnosed with primary phagocytic syndrome by knowing that the parents were consanguineously married. If we say that the first baby had phagocytic syndrome, can the second baby also get the disease? Theoretically, it is possible, but the second child may not always have the disease and genetic screening is needed to determine this.