Description
Case Study 2: Genetic Control of Cell Function and Inheritance
Marsha and Clement are both carriers of sickle cell anemia, a disease that is autosomal recessive. Their first child, Amelia, does not have the disease. Marsha and Clement are planning another pregnancy, but they are concerned about their second child having the condition. Clement’s father died from complications of sickle cell disease shortly before Amelia was born.
1. Draw a Punnett square to determine the likelihood of Marsha and Clement having a baby with sickle cell anemia. What is the chance the baby will be a carrier of the disease, just like the parents?
2. Marsha suggested to the nurse at the local family planning clinic that if the baby were a boy, he might have a higher risk of developing the disease, just like his grandfather. If you were this nurse, how would you respond?
3. When Amelia, who does not have sickle cell anemia, grows up and marries someone who does have the disease, how likely will her children have the disease?
Case Study Assignment Requirements:
1. **Likelihood of Marsha and Clement Having a Baby with Sickle Cell Anemia**:
Marsha and Clement are both carriers of sickle cell anemia, meaning they each have one normal hemoglobin gene (HbA) and one mutated gene (HbS). To determine the likelihood of their second child having sickle cell anemia, we can use a Punnett square:
– Marsha’s genotype: HbA/HbS
– Clement’s genotype: HbA/HbS
The Punnett square would look like this:
“`
HbA HbS
|——|——|
| HbA | HbA |
|——|——|
| HbS | HbS |
|——|——|
“`
From this Punnett square, we can see that there’s a 25% chance (1 in 4) that the baby will have sickle cell anemia (HbS/HbS), a 50% chance (2 in 4) that the baby will be a carrier like the parents (HbA/HbS), and a 25% chance (1 in 4) that the baby will have normal hemoglobin (HbA/HbA).
2. **Response to Marsha’s Concern**:
Marsha’s suggestion that a baby boy might have a higher risk of developing the disease, like his grandfather, is not accurate. Sickle cell anemia is an autosomal recessive genetic disorder, which means it is not linked to gender. Both boys and girls have an equal risk of inheriting the disease if both parents are carriers.
As the nurse, you should explain to Marsha that the risk of sickle cell anemia is determined solely by genetics and is not related to the baby’s gender. Each child, whether a boy or a girl, has the same risk of inheriting the disease if both parents are carriers.
3. **Likelihood of Amelia’s Children Having the Disease**:
If Amelia, who is a carrier (HbA/HbS), marries someone with sickle cell disease (HbS/HbS), we can calculate the likelihood of their children having the disease:
– HbA/HbS (Amelia) x HbS/HbS (Spouse with Sickle Cell Disease)
The offspring have a 50% chance of having sickle cell anemia (HbS/HbS) and a 50% chance of being carriers (HbA/HbS). The gender of the child does not affect these probabilities.
Please ensure you cite at least three references from peer-reviewed journal articles, textbooks, or evidence-based practice websites in your case study paper, following APA 7th edition format. Make sure your paper has at least four full pages of analytic content, double-spaced, excluding the cover and reference pages, and meets all other assignment requirements.
1. Punnett Square Analysis: To determine the likelihood of Marsha and Clement having a baby with sickle cell anemia, we need to understand their genotypes. Both Marsha and Clement are carriers (heterozygous) for sickle cell anemia. This means they each have one normal hemoglobin gene (HbA) and one mutated gene (HbS).
Use “A” to represent the normal hemoglobin gene (HbA) and “S” for the mutated hemoglobin gene (HbS). Their genotypes are:
Marsha: HbA/HbS Clement: HbA/HbS
Now, let’s create a Punnett square to determine the likelihood of their offspring’s genotypes:
So, there is a 25% chance that Marsha and Clement’s child will have sickle cell anemia (HbS/HbS), a 50% chance that the child will be a carrier like the parents (HbA/HbS), and a 25% chance that the child will have normal hemoglobin (HbA/HbA).
2. Response to Marsha’s Concern: Marsha’s suggestion that a boy might have a higher risk of developing the disease, like his grandfather, is not accurate. Sickle cell anemia is an autosomal recessive disorder, which means it is equally likely to affect both males and females. The risk of inheriting the disease is the same for all children, regardless of their gender.
As the nurse, you should explain to Marsha that the risk of the baby having sickle cell anemia is the same whether it’s a boy or a girl. The gender of the child does not affect the inheritance of this autosomal recessive condition.
3. Likelihood of Amelia’s Children Having the Disease: Since Amelia is a carrier of the sickle cell trait (HbA/HbS) and she marries someone who has the disease (HbS/HbS), we can use a Punnett square to determine the likelihood of their children having the disease:
There is a 50% chance that each of Amelia’s children with her spouse who has sickle cell disease will have the disease itself (HbS/HbS) and a 50% chance that they will be carriers (HbA/HbS).
