One Gene, Two Diseases
Genetics domain · Lesson 8 of 20 · Medical Interventions (MI), with PBS overlap
Today's goal: Students will connect mutation mechanism to phenotype, contrasting haploinsufficiency (truncating, milder Van der Woude) with dominant-negative action (DNA-binding-domain missense, more severe popliteal pterygium).
What a finished product looks like
This is a model of the work you should turn in. Use it to check your own: match the structure and the level of detail, do not copy it. Your wording should be your own.
Mechanism-to-disease note:
- Relative 1, R250X (a truncating/nonsense change spread across the gene): likely mechanism is haploinsufficiency; one copy makes no usable protein, so the cell runs on half-dose. Likely disease is milder Van der Woude syndrome.
- Relative 2, R84C (a missense in the DNA-binding domain): likely mechanism is dominant-negative; the full-length but broken protein pairs with the good copy and ruins the grip, dropping function below half. Likely disease is more severe popliteal pterygium syndrome.
Reasoning: mechanism predicts severity, because a dominant-negative protein actively interferes with the good copy while haploinsufficiency only removes one copy's output.
Also due today: Give one reasoning sentence per relative.
How this was built, step by step
The finished product above did not appear all at once. Here is the path from the question to the turned-in work, so you can follow the same steps.
- 1Start from today's question: Why does one gene cause two different diseases?
- 2Work the Model and the Explore questions to reason it out before writing anything.
- 3Pull the specific evidence the product needs from the reading and any database you used.
- 4Write it up in the required format: For two of Mateo's relatives' IRF6 results (R250X and R84C), name the likely mechanism ( or ) and the likely disease (milder VWS or more severe PPS), with one-sentence reasoning each.
- 5Check it against the rubric, then submit.
| Criterion | Proficient | Developing | Beginning |
|---|---|---|---|
| Complete | Every required part of the artifact is present and filled in. | Most parts are present, but one is missing or left blank. | Several parts are missing. |
| Accurate | The science and data are correct and match the evidence. | Mostly correct, with a small factual slip. | Key science or data is wrong. |
| Scientific reasoning (CER) | States a claim, backs it with specific evidence, and explains the reasoning. | Has a claim and evidence, but the reasoning is thin or missing. | Gives an answer with no evidence or reasoning. |
| Professional communication | Clear, organized, and labeled the way a clinician or scientist would write it. | Readable but disorganized or missing labels. | Hard to follow. |
| Submitted | Turned in the right way (Schoology for routine work) and confirmed. | Turned in, but in the wrong place or unconfirmed. | Not turned in. |
- CompleteProficient: Nothing is left blank: the model fills every part of "For two of Mateo's relatives' IRF6 results (R250X and R84C), name the likely mechanism (haploinsufficiency or dominant-negative) and the likely disease (milder VWS or more severe PPS), with one-sentence reasoning each.".
- AccurateProficient: Every number and claim matches the case evidence.
- Scientific reasoning (CER)Proficient: It names a claim, cites the specific evidence, and explains the reasoning, not just the answer.
- Professional communicationProficient: It is organized and labeled like a real chart note.
- SubmittedProficient: It would be turned in on Schoology and confirmed.
WebXam problem for today's skill
One exam-style question that uses exactly what you practiced today. Try it before you reveal the answer, then read why each choice is right or wrong.
Tap an answer to see the full explanation. Nothing is recorded or graded.