Human Genetic Variation
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Activity 3 - Molecular Medicine Comes of Age - return to student activities home high school student taking notes
Overview New Data  

Transcripts for Activity 3 Videos

Video 1 - Team Coordinator
Video 2 - Physiologist
Video 3 - Molecular Biologist
Video 4 - Biostatistician
Video 5 - New Data

Video 1 - Team Coordinator

This is Lucy.

This is Michael checking in.

Good morning. This confidential communication is addressed to all of the AXR staff working on the bronchodilator project.

As you know, the X-9 bronchodilator represents a new product line for us, one the directors are keenly interested in. The preliminary test results on the drug's effectiveness are inconclusive. Approximately half of the 270 children tested reported significant or noticeable relief from their wheezing, but the rest reported no effect at all.

What's going on here?

To make this drug marketable, we needed to find exactly who it is effective with and why. It's your job to find a pattern, if there is one.

Video 2 - Physiologist

The boss has asked me to give the team some background on this product.

Asthma is a respiratory problem that affects about 3 to 5 percent of people sometime in their lives. Most asthma is caused by an allergic reaction to foreign substances in the air, such as pollen, dust, or pet hair.

During an asthma attack, the smooth muscle and the small tubes inside the lungs contract. This contraction causes troubled breathing. A bronchodilator is a drug that relaxes the muscles, making it easier to breathe again. Ideally, a bronchodilator should work quickly and uniformly for everyone, with no side effects.

Video 3 - Molecular Biologist

Sometimes it's useful to look at what we've learned in similar situations with other drugs.

One of our competitors produced a drug for treating Alzheimer's disease, which was effective with some people but not with others. Their research showed that this drug was effective with people who had one of two forms of the ApoE gene but was not effective with people who had a third form of the gene.

People with the E2 or E3 form of the gene responded well to treatment with this drug. But people with the E4 form of the gene did not respond well. This discovery suggests a way for us to know in advance which patients the drug would be effective with.

Video 4 - Biostatistician

My job has been to analyze the results of the preliminary trials on X-9.

We gave either X-9 or a placebo to a group of randomly selected children who suffer from asthma. Each child completed a survey rating the amount of relief they felt after using the treatment.

The results were promising because they showed that X-9 did help some children.

Now we need to determine what it is that causes the drug to be effective with some children but not others.

Does gender make a difference? Does it matter whether or not the child has a pet, or is it something else that makes the difference?

Video 5 - New Data

We've been studying how X-9 works and have discovered that it binds to a particular type of muscle protein. Different people have different forms of this protein depending on the genes for this protein that they inherit from their parents.

One form of the gene causes the amino acid arginine to be located at position 16 of the protein, and another form of the gene causes the amino acide glycine to be located there instead.

As the table shows, this difference in genotype and the resulting difference in protein structure may explain why X-9 is effective with some people but not others.

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