Clue 1: Orient yourself
Who acts before the middle runner?
Use the labels and the picture's left-to-right, near-to-far, or before-and-after order. Name only what you can point to.
The question
How can breaks in different instructions end in the same kind of cleft?
Why it matters: Genetic results can change family counseling and research decisions. They must be interpreted without turning risk into destiny or an uncertain variant into a diagnosis. Today you practice the professional reasoning behind that work: IRF6 works in a regulatory network, so similar phenotypes can arise when different connected genes fail.
On your WebXam
Placing a gene in a regulatory network from patient and experimental clues
For life
One result can have many causes; the outcome alone never tells you which.
Principle: Many roads, one ending
Five principles we return to
Having it is not using it
Same instructions, different switches
Same look, different cause
Change one thing and watch
Boss or doorman?
Decides the result or only allows it
Held down, not gone
Remove the brake and it returns
Many roads, one ending
One result can begin many ways
Try the everyday version first
A relay team passes one signal through several runners
A relay depends on both running and passing the baton. Each handoff must occur before the next runner can continue the shared route.
Do not jump to the biology yet. Treat the picture as a small system. Track its parts, follow one change at a time, and keep more than one explanation open until the picture supplies a way to separate them.
Clue 2: Trace one change
Which handoff could stop the same finish?
Follow one object, stage, or path. Point to the first place where the situation changes instead of jumping to the ending.
Clue 3: Keep the cause open
Why would two different failed runners create similar outcomes?
List more than one explanation that still fits. Name the extra observation that would help you separate those possibilities.
Now inspect the illustration
Work from the visible evidence. A useful answer names the part of the picture that supports it and leaves unknown causes open.
- 1Who acts before the middle runner?
- 2Which handoff could stop the same finish?
- 3Why would two different failed runners create similar outcomes?
Tier 1 check
Finish with the everyday model
Use the everyday picture to answer today's question in plain words: How can breaks in different instructions end in the same kind of cleft?
You can complete today's required check without opening the technical details below.
Ready for the real names? Optional tier 2
Technical rules and limits
Rule 1: Name upstream and downstream relationships.
Rule 2: Different nodes can converge on one cell behavior.
Rule 3: Network redundancy can soften or redirect a failure.
Where the analogy stops: Gene networks branch, feed back, and vary by tissue, unlike a straight relay.
Carry the previous idea forward
A missense variant matters when its side-chain change disrupts a specific protein interaction or fold.
Today's technical takeaway
IRF6 works in a regulatory network, so similar phenotypes can arise when different connected genes fail.
Now map the same rules onto biology
Place p63, IRF6, GRHL3, and KLF genes in a network
Earlier runner
Upstream regulator
Baton handoff
Transcriptional regulation
Finish-line action
Epithelial differentiation and safe fusion
Educational illustration, not a clinical photograph or diagnostic result. Use the labeled evidence cards and claim ceiling.
Mateo's case file: evidence supplied in this lesson
GEN13-E1
p63 and TGF-beta signaling influence IRF6 expression or activity in oral epithelium.
Why it matters: IRF6 has upstream regulators.
GEN13-E2
IRF6 promotes GRHL3, KLF4, and KLF17-related differentiation programs.
Why it matters: IRF6 connects to downstream targets.
GEN13-E3
GRHL3 variants can also cause Van der Woude-like phenotypes.
Why it matters: Different network nodes can converge on similar outcomes.
Make the clinical decision
You are explaining a negative IRF6 test in a family with lip pits and clefting.
IRF6 sequencing is negative, but the phenotype remains strongly suggestive of the network.
AConsider other connected genes and broader testing.
BConclude the phenotype is impossible.
CInvent an IRF6 variant.
Choose the next genetic strategy and cite network convergence.
Evidence required
GEN13-E1 + GEN13-E2 Claim ceiling
You may broaden the candidate network. You may not diagnose a specific second gene without evidence.Go deeper Optional tier 3
Everything required for today is above. Open these only if you want the explainer, source trail, or download files.
The everyday model and Tier 1 check are the complete required path for this lesson.
Use these checks to keep your place. They are not turned in through the portal.
Check off as you finish
- Worked through the everyday picture and answered its three questions.
- Completed the Tier 1 check in plain words.
Turn in: Genetics lesson 13: Does IRF6 Work Alone?
Go to Schoology to turn this in.
Submit one PDF. Put your first and last name in the document header. Name the file: FirstName LastName - Assignment Title - YYYY-MM-DD.pdf.
Open Schoology PDF upload helpIf you cannot get in, see Mr. Mendoza. Do not skip the work.
Optional legacy technical materials Open only if you want the original notes, vocabulary, artifact, and CER work
Before this page, you should know
- predicts a 's folded 3D shape from its amino-acid sequence; the IRF6 model is AF-O14896-F1.
- A swaps one amino acid for a different one; every amino acid has a with its own size and charge.
If not, review
Today's new idea is only
IRF6 does not work alone: it is one node in the p63 to IRF6 to GRHL3 network, which is why two patients can have the same from breaks in different genes of the same circuit.
Goal: Read a from patient and experimental clues, and place IRF6 in the p63 to IRF6 to GRHL3 axis with KLF4 and KLF17 .
Know by the end
- A is a set of genes that switch one another on and off to run a process.
- A is a that turns other genes on or off; IRF6, GRHL3, and p63 are all factors.
- p63 (TP63) is and keeps IRF6 switched on in the ; IRF6 hands the signal to KLF4 (mouse) and KLF17 (zebrafish).
- GRHL3 is a partner of IRF6 in the same pathway, because either one failing causes the same Van der Woude phenotype.
1
Upstream, downstream, partners
Model start: A is a gene whose switches other genes on. A gene that acts earlier and controls another is ; a gene that acts later and receives the signal is .
- p63 (TP63) is near the top and keeps ____ switched on in the .
- IRF6 hands the signal to ____ (mouse) and KLF17 (zebrafish).
- Because either IRF6 or GRHL3 failing causes Van der Woude, they are ____ in the same pathway, not a single point of control.
2
Why one disease can have several genes
- Two patients can have the same from breaks in ____ genes of the same circuit.
- means more than one gene can cover a similar job, so losing one is partly ____.
Everything you need for today is on this page. These links are optional.
What to read
Read the short plain-language explanation written for this lesson. Plain-language explainer for this lesson
Why this source matters
This explanation gives you the background for today's idea without making you decode a research paper: IRF6 does not work alone: it is one node in the p63 to IRF6 to GRHL3 network, which is why two patients can have the same from breaks in different genes of the same circuit.
Words to unlock first
Reading moves
- Skim the title and abstract first to get the gist.
- Circle the one sentence that states the main claim.
- Box the evidence the authors give for that claim.
- Mark one sentence that confuses you, and move on.
Stop point
Stop after the final 'Use it now' section. The research citations are available separately for advanced readers.
Your output
Write one claim-evidence sentence: state the main idea, then name the example or evidence that supports it.
Where this fits
Tested on (Ohio WebXam)
Genetics of Disease · 072130
PLTW lesson
MI · Genetics domain · Gene regulation and transcription factors
WebXam domain
Molecular and Genetic Technology
Evidence to produce
Mateo's first IRF6 test came back normal, but his clinical features still strongly suggest a periderm-network problem. As the systems geneticist, write the lab's next-step order: list two or three other genes from this network to sequence, and for each give a one-line reason based on whether it sits upstream of, alongside, or downstream of IRF6.
Lab / skill
Medical Interventions (MI) · AP Biology
Everything required for today's decision is already in the case file and plain-language explainer. The links below are original papers and database records for teachers and advanced readers, not assigned student reading.
- Claim: IRF6 is one node in a network, not a lone cause of clefting (agree or disagree).
- Evidence: Some Van der Woude patients have a in ____ instead of IRF6, and ____ is needed to keep IRF6 switched on.
- Reasoning: and relationships let different genes cause the same outcome, so a break ____ in the same circuit can look like a broken IRF6.
How this is graded (rubric)
For: Mateo's first IRF6 test came back normal, but his clinical features still strongly suggest a periderm-network problem. As the systems geneticist, write the lab's next-step order: list two or three other genes from this network to sequence, and for each give a one-line reason based on whether it sits upstream of, alongside, or downstream of IRF6.
| 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 through the route named under Submit here and confirmed. | Turned in, but in the wrong place or unconfirmed. | Not turned in. |
How the model answer scores against this rubric
- CompleteProficient: Nothing is left blank: the model fills every part of "Mateo's first IRF6 test came back normal, but his clinical features still strongly suggest a periderm-network problem. As the systems geneticist, write the lab's next-step order: list two or three other genes from this network to sequence, and for each give a one-line reason based on whether it sits upstream of, alongside, or downstream of IRF6.".
- 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 attached to your class form or handed in, and confirmed.
What's next: We placed IRF6 in a network with p63 above it and GRHL3 and the KLFs alongside and below. But a network of genes is just instructions. What does this network actually make the cells of the do so the lip and can physically close? We chase that next.