Ho-2 is created due to a point mutation causing the substitution of histidine by aspartic acid. The other explanation is that there is an unequal crossing over between two α genes which explains the replacement of histidine by aspartic acid. This then led a deletion occurring within the chromosome housing Ho-2. This deletion removes the region where the N-terminus is located in the major α-chain and where the c-terminus is located on the minor α-chain. Deletion of the N-terminus inactivates enzymes and halting their ability to cut chains at certain areas, which inevitably damages the chain. Case studies Case studies were completed on some patients who carried the Hemoglobin Hopkins-2 genetic mutation by Samuel Charache and others. Researchers concluded after completing the studies that many of carriers of the mutation were asymptomatic to sickle cell and were overall quite healthy. Any medical issues that occurred had no correlation to sickle cell. These studies occurred in the 1970s. Fuller-Carr family There were five carriers of Hemoglobin Hopkins 2 in the Fuller-Carr family and ten double heterozygotes of Ho-2 and Hemoglobin S. All the carriers were in good health and had normal hematology test results. Out of those carrying hemoglobin S and Ho-2, none were anemic; but, a few of those studied displayed elevated reticulocyte counts. This is measured through a blood test that analyzes the speed of production of red blood cells by bone marrow and its release into the blood. There was no suggestion of symptomatic sickle cell anemia in the family. Unknown child There was a study on a three-year-old that was a carrier of the hemoglobin variant of Hopkins-2. The child had mild anemia and reticulocytosis, which is commonly seen in anemia. There were, however, no sickled cells found in the blood and they had no symptoms relating to sickle cell. There was also a reduced mean corpuscular volume (MCV), which is the average volume of red blood cell count. References Hemoglobins Disorders of globin and globulin proteins Mutation