A 15-Year-Old Boy Is Found to Have Unexplained Erythrocytosis on Routine

question 152

Multiple Choice

A 15-year-old boy is found to have unexplained erythrocytosis on routine laboratory analysis.  Evaluation of his immediate family shows that his father and sister also have elevated red cell levels.  Genetic sequencing of the β-globin gene is performed in the affected family members.  The results show a single base substitution at amino acid position 82 that replaces the normal lysine residue with methionine.  Further analysis shows that this amino acid replacement impairs the ionic interaction between the β-subunit and 2,3-bisphosphoglycerate.  As a result of this mutation, the patient's hemoglobin will be most similar to which of the following hemoglobin types?

• A)Hemoglobin A_1c
• B)Hemoglobin C
• C)Hemoglobin F
• D)Hemoglobin H
• E)Hemoglobin S

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Definitions:

Source Inspection

Controlling or monitoring at the point of production or purchase— at the source.

User-Based Definition

A user-based definition refers to the explanation or interpretation of a concept, term, or system based on the perspective or use case of the end-user.

Product-Based Definition

An approach that defines a product by its features, components, and attributes rather than its function or the customer need it satisfies.