In reality, the human body is an extraordinarily complex and multistage system characterized by genetic malfunctions. Mutations in certain regions of DNA can cause pathological metabolic abnormalities or hereditary features realized through dysfunctional disorders. One such condition is sickle cell anemia, which has a genetic basis. Typically, the human blood contains the active protein Hemoglobin, which is several branched chains.
When the HBB gene located in chromosome 11 is damaged, the synthesis of normal hemoglobin A is disrupted, and instead, the body produces hemoglobin S, which changes the shape of red blood cells (HBB Hemoglobin). This, as is known, sickle cell anemia is inherited by autosomal recessive type: this type of inheritance means that for guaranteed disease, the patient’s genotype must be represented by two recessive alleles mutation itself localized not in the sex chromosome.
In the case of incomplete dominance, two forms of red blood cells in approximately equal numbers (Sickle Cell Anemia) are observed in the patient’s blood at once. However, the presence of elongated blood cells in the body does not mean that the individual is sick. In fact, such a patient is a carrier of a recessive gene, or in other words, a sickle cell trait, whereas sick people show a full symptomatic spectrum.
According to the proposed scenario, the man is a sick patient, while the woman is absolutely healthy and is not a carrier of the latent gene. Given the nature of the inheritance of sickle cell anemia, the scheme below can be considered. For instance, John’s genotype is homozygous and recessive for this trait, while the Ann’s genotype, on the other hand, is dominant. Then, their gametes’ fusion produces zygotes in which both the dominant and recessive alleles are present. This means that these parents’ children will not have the pathology, but they will be carriers of the gene. Therefore, their offspring may be susceptible to the disease, depending on the genotype of the future partner.
Work Cited
“Sickle Cell Anemia.” Cleveland Clinic, 2019. Web.
“HBB Hemoglobin Subunit Beta.” NCBI. 2021. Web.