FiltersDone

Question type

Essay

Multiple Choice

Short Answer

True False

Matching

Exam 10: Hemoglobinopaties: Qualitative Defects

Show Answer

Share

---

All types

Filters

Study FlashcardsPractice ExamLearn

Question 1

Essay

Review LaterAdd Note

Review Later

Explain how methemoglobin is formed, and how its presence impacts oxygen delivery.Be sure to include oxygen affinity in your answer.

Correct Answer

verified

Methemoglobin is formed by oxidation of ferrous iron to ferric iron in the hemoglobin molecule.As a result, it cannot effectively transport oxygen, due to poor oxygen affinity.Patients with this abnormal hemoglobin will have cyanosis and shortness of breath as a result of poor oxygen transport.

Question 2

Essay

Review LaterAdd Note

Review Later

Patients with sickle-cell disease and those with sickle-cell trait differ greatly in clinical presentation.List at least two features in clinical presentation, and explain why they differ.

Correct Answer

verified

Patients with sickle-cell disease report...

View Answer

Show Answer

Question 3

Multiple Choice

Review LaterAdd Note

Hemoglobinopathies are detected by which laboratory method?

Use this case to answer the following questions: A 2-year-old black male was being evaluated at the County Clinic for swollen hands and feet that were extremely painful. Upon physical examination, the child was found to have a fever and hepatosplenomegaly, and was physically small for his age. The child was of Jamaican descent. Patient history revealed that the child was normal for his birth weight, but since then, he was consistently underweight and undersized for his age group. Family history was not readily available. The physician had the child admitted to the hospital for workup and ordered the following CBC. $\begin{array}{ll}\text { TEST } & \text { RESULTS } \\\text { WBC } & 16.6 \times 10^{9} / \mathrm{L} \\\text { RBC } & 2.53 \times 10^{12} / \mathrm{L} \\\text { HGB } & 7.5 \mathrm{gm} / \mathrm{dL} \\\text { HCT } & 21.4 \% \\\text { MCV } & 84.6 \mathrm{fl} \\\text { MCH } & 18.9 \mathrm{pg} \\\text { MCHC } & 35.0 \mathrm{~g} / \mathrm{dL} \\\text { RDW } & 18.9 \\\text { PLT } & 511 \times 10^{9} / \mathrm{L}\\\text { Differential: }\\\text { Polys } & 84 \% \\\text { Stabs } & 10 \% \\\text { Lymphs } & 5 \% \\\text { Eos } & 1 \% \\\text { NRBCs } & 12\end{array}$ -Hemoglobinopathy results from a genetic abnormality of which structure within the hemoglobin molecule?

Hemoglobin C disease has altered solubility properties similar to hemoglobin S disease.What accounts for this altered solubility?

In Hemoglobin C disease how does the mutation affect the hemoglobin molecule?

If a patient had hemoglobin S and hemoglobin A identified by electrophoresis and a positive hemoglobin solubility test, what is the most likely condition of the patient?

In hemoglobin C disease, the life span of the cell is decreased to what length?

How is methemoglobin detected in the laboratory?

Both hemoglobin D and G migrate with which hemoglobin on alkaline gel electrophoresis?

Electrophoresis at an acid pH using a citrate agar gel separates what hemoglobin variants that travel together on cellulose acetate at pH 8.6?

Disease that results from a molecular defect in hemoglobin synthesis in RBCs is termed:

Use this case to answer the follwing questions: During a discussion of RBC indices, a medical technologist of Cambodian origin mentioned that her own red cells were small in a CBC per?formed two years earlier in a routine physical. A more recent CBC showed the following results. $\begin{array}{ll}\text { TEST } & \text { RESULTS } \\\text { WBC } & 9.3 \times 10^{9} / \mathrm{L} \\\text { RBC } & 6.11 \times 10^{12} / \mathrm{L} \\\mathrm{HGB} & 13.0 \mathrm{~g} / \mathrm{dL} \\\mathrm{HCT} & 41.8 \% \\\text { MCV } & 69.6 \mathrm{fL} \\\text { MCH } & 22.5 \mathrm{pg} \\\text { MCHC } & 31.0 \mathrm{~g} / \mathrm{dL} \\\mathrm{RDW} & 15.8 \\\mathrm{PLT} & 351 \times 10^{9} / \mathrm{L}\\\text { Differential }& \text { Within normal limits }\\\end{array}$ -What reflex test is most appropriate to investigate these results?

Other than hemoglobin S, name two abnormal hemoglobins that produce a positive sickle solubility test.Explain how they could be differentiated from HbS.

The peripheral blood smear contains a normocytic, normochromic morphology with marked reticulocytosis.The hemoglobin solubility test is positive.What confirmatory test should follow?

A patient has a positive sickle solubility test.Further investigation reveals hemoglobin of 8.5 g/dL.What can be done to confirm these findings? Explain your answer.

What is the purpose of treating sickle-cell patients with hydroxyurea?

Which of the following has the highest prevalence worldwide?

Use this case to answer the following questions: A 2-year-old black male was being evaluated at the County Clinic for swollen hands and feet that were extremely painful. Upon physical examination, the child was found to have a fever and hepatosplenomegaly, and was physically small for his age. The child was of Jamaican descent. Patient history revealed that the child was normal for his birth weight, but since then, he was consistently underweight and undersized for his age group. Family history was not readily available. The physician had the child admitted to the hospital for workup and ordered the following CBC. $\begin{array}{ll}\text { TEST } & \text { RESULTS } \\\text { WBC } & 16.6 \times 10^{9} / \mathrm{L} \\\text { RBC } & 2.53 \times 10^{12} / \mathrm{L} \\\text { HGB } & 7.5 \mathrm{gm} / \mathrm{dL} \\\text { HCT } & 21.4 \% \\\text { MCV } & 84.6 \mathrm{fl} \\\text { MCH } & 18.9 \mathrm{pg} \\\text { MCHC } & 35.0 \mathrm{~g} / \mathrm{dL} \\\text { RDW } & 18.9 \\\text { PLT } & 511 \times 10^{9} / \mathrm{L}\\\text { Differential: }\\\text { Polys } & 84 \% \\\text { Stabs } & 10 \% \\\text { Lymphs } & 5 \% \\\text { Eos } & 1 \% \\\text { NRBCs } & 12\end{array}$ -Based on these findings, what test would be the logical next step?

Thalassemias are produced as a result of: