Download Diagnose the Patient: Genetic Disorder

NAME: ________________________________________________________ Period: 5
Genetics Case Study: Diagnose the Patient
Part 1: Read patient M.J.'s history
Patient M.J. is a 19 year-old African-American male. M.J. reports feeling well most of the time, but
he also reports that odd events have been reoccurring recently. For instance, one day after a short swim
he became so tired that he could hardly move. He became short of breath and complained of pain in his
joints and muscles. He felt unusually weak and required bed rest lasting a few weeks. These symptoms
occurred repeatedly during his youth.
A family history reveals that M.J. has two brothers and three sisters. One of his sisters also suffers
from this condition. His uncle and his grandmother on his mother's side often had similar symptoms. His
grandmother died at the age of 25 years. His parents do not have this condition.
Questions:
1. List TWO (2) symptoms that this patient is suffering from.
2. Do you believe that this patient is suffering from a genetic disorder? Why or why not?
Part 2: Analysis of the patient's DNA
Hemoglobin (abbreviated as Hb) is a protein that is found in red blood cells. This protein is responsible
for transporting oxygen in the blood. The gene for hemoglobin production (HBB) is found on
chromosome 11. The gene of the patient was sequenced and compared to that of a healthy sample.
Task: Transcribe and translate the normal DNA and the patient's DNA. Use the amino acid chart on
the last page to find the amino acids encoded by this fragment of DNA.
Questions:
1. Amino acid sequence:
Normal: _______________________________________________________________________________________
Patient: _______________________________________________________________________________________
2. What is the type of mutation that has occurred in the base sequence of the DNA?
Part 3: Analyze the hemoglobin protein structure
The images below represent the 3D structures of hemoglobin (Hb) in a healthy person and in the patient.
Questions:
1. Describe how the patient's hemoglobin (Hb) differs from a health person's.
2. Suggest how this change in hemoglobin (Hb) structure might lead to a difference in the shape of the red
blood cells.
Part 4: Analyze a blood sample
Below are illustrations of a healthy individual's erythrocytes (red blood cells) on the left and the patient's
erythrocytes on the right.
Healthy Erythrocytes 
 Patient's Erythrocytes
Questions:
1. Describe how the patient's erythrocytes (red blood cells) differ from a healthy person's.
2. Suggest reasons why the patient felt some of his symptoms.
3. Use the Internet or other resources to research what disorder patient M.J. is suffering from. Give
reasons for your final diagnosis.
Amino Acid Chart for Translation