Genotype can be simply defined as the genetic constitution of an individual organism.
This is different from your phenotype which is a description of your actual physical characteristics. It is imperative to know your genotype before you say “yes” to that handsome guy or to that beautiful lady whom you wish to spend the rest of your life with or if you are in a relationship in which there are chances of conception.
The problem to avoid with genotype compatibility for intending couples is the sickle cell disease (a recessive disorder)--a very serious medical condition with high prevalence rates in Africa south of the Sahara.
Types of Genotype
The genotypes in humans are AA, AS, AC, SS. They refer to the hemoglobin gene constituents on the red blood cells. AC is rare whereas AS and AC are abnormal.
Genotype Compatibility Chart
Study this table below carefully:
AA + AA = AA, AA, AA, AA (Excellent)
AA + AS = AA, AS, AA, AS, (Good)
AA + SS = AS, AS, AS, AS, (Fair)
AA + AC = AA, AA, AA, AC. (Good)
AS + AS = AA, AS, AS, SS, (Very Bad)
AS + SS = AS, SS, SS, SS, (Very Bad)
AS + AC = AA, AC, AS,SS. (Bad; Advice needed)
SS + SS = SS, SS, SS, SS, (Very Bad)
AC + SS = AS, AS, SS, SS, (Very Bad)
AC + AC = AA, AC, AC, SS. ( Bad; Advice needed)
Compatible genotypes for marriage are:
AA marries an AA. That’s the best compatible. That way you save your future children the worry about genotype compatibility.
AA marries an AS. You’ll end up with kids with AA and AS which is good. But sometimes if you’re not lucky all the kids will be AS which limits their choice of partner.
AS and AS should not marry, there is every chance of having a child with SS.
AS and SS shouldn’t think of marrying.
And definitely, SS and SS must not marry since there’s absolutely no chance of escaping having a child with the sickle cell disease.
The only thing that can change the genotype is the bone marrow transplant (BMT). It has been proven to be the only promising permanent cure to SS, SC, and CC; however, it is new, very expensive and cannot be done in any part of Africa. It also carries some risks.
Health tips are supplied by the AUN Health Center