White blood cells (WBCs), red blood cells (RBCs), platelets and plasma. The most dominant out of the four is the RBCs. Red blood cells contain hemoglobin, a substance that carries oxygenated blood to all the tissues in the body.
The hemoglobin is divided into two parts, the Heme, and the globin. However, the part relevant to our study now is the globin parts.
The globin parts contain 2 alpha and 2 beta chains that are normally structured.
A problem arises whenever there is a protein substitution in any of the globin chains.
For example, if amino acid ‘A’ is normal, an error occurs when it is replaced by ‘B’ instead of the normal ‘A’.
This error in substitution of an amino acid is called thalassemia or hemoglobinopathy.
Genotype AA: At position 6 of both globin chains, the amino acid is GLUTAMATE
Genotype AS: At position 6 of the 1st globin chain, it is GLUTAMATE and at position 6 of the 2nd globin chain, the amino acid is VALINE
Genotype SS: At position 6 of both globin chains, the amino acid is VALINE
Genotype AC: At position 6 of the 1st globin chain is GLUTAMATE and at position 6 of the 2nd globin chain, you have LYSINE.
Sometimes, people ask about AS and AC genotype compatibility for marriage. However, an AC carrier is always advised not to marry an AS because there is a 1 in 4 chance of producing an SC baby. An SC is still a sickle cell disease but in a milder form than SS. Knowing your genotype before marriage is the key to avoiding genotype crises that may arise.
AC Genotype Symptoms
AC genotype is an abnormal hemoglobin produced because of the substitution of glutamate with lysine at the 6th position of the second beta-globin chain.
People with hemoglobin AC traits are phenotypically normal with no clinical symptoms.
However, those with hemoglobin CC may experience a mild degree of hemolytic anemia, borderline anemia, and splenomegaly but not as complicated as hemoglobin S. (2)
AC Genotype and Malaria Resistance
AC and AS genotype has been reported to have a lower risk of malaria parasites compared with AA genotypes.
This is in line with a publication made by the National Center for Biotechnology Information, where 452 children with different hemoglobin genotypes were monitored for one year.
This was done to determine the clinical malaria incidence of different hemoglobin genotypes. The results showed that HB AA has the highest risk of a malaria attack, while SS has the lowest. Below is the result: 73.2% AA; 15.0% AC; 8.2% AS; 2.2% CC; 1.1% CS and 0.2% SS. (3)
Sickle cells are real, it is imperative to know your genotype and your HB compatible before marriage to avoid genotype crisis that may arise and remember that prevention is better than cure.