Rough draft.This research track is under review with Dr. Atit's lab. Content and sequence may still change.
The Baby Mateo Case
Disease domainShared clinical backbone (the cleft team)Lesson 8 of 20Your seat: Epidemiologist
How Common Is Mateo's Cleft, and in Whom?
Discovery question
How common is a like Mateo's, and which babies does it happen to most?
💡 Mateo fits the single most common pattern in every category, which makes his cleft look common and patterned, not a rare random event.
The plan
Prerequisite check
Before this page, you should know
- is a small lower jaw; is the tongue falling backward; together they can cause .
- (PRS) is plus plus with a wide .
If not, review
Today's new idea is only
Mateo fits the single most common pattern in every category, which makes his cleft look common and patterned, not a rare random event.
Learn first
What you will learn
Goal: Students will read real epidemiology data and describe how prevalence varies by cleft type, sex, ancestry, and , then locate Mateo's profile within the most common pattern.
Know by the end
- is the number of affected babies per total births; orofacial clefting affects about 1 in 700 live births worldwide, so it is common, not rare.
- By type, lip and together (CLP) is most common at about 45%, with cleft palate only about 40% and cleft lip alone about 15 to 25%.
- By sex, lip with or without is about 2:1 male-to-female; by , outnumber about 4:1 and about 70% of unilateral clefts are left-sided.
- By ancestry, prevalence is highest in Asian and Amerindian groups, intermediate in European-derived, and lowest in African-derived; exact rates vary by study and no single verified Native American prevalence number is settled.
Learn first
Model: Cleft numbers across the population, and prevalence by ancestry
Real birth-prevalence and pattern data for orofacial clefts (from two reviews and a meta-analysis). How common overall: about 1 in 700 live births worldwide (about 1.5 per 1000), roughly 220,000 new cases a year. Most common type: lip AND together (CLP) about 45%, cleft palate only about 40%, cleft lip alone about 15 to 25%; pooled CLP prevalence is 0.45 per 1000 (95% CI 0.38 to 0.52). Sex: about 2 boys for every 1 girl for cleft lip with or without palate. : (one side) outnumber about 4 to 1; of one-sided clefts, about 70% are left-sided.
Prevalence by ancestry: highest in Asian and Amerindian (Native American) groups, often about 1 in 500 and up to about 4 per 1000; intermediate in European-derived groups, about 1 in 1000; lowest in African-derived groups, about 1 in 2500. Read these as levels (highest, middle, lowest), not as precise constants. The highest group is consistently Asian and Amerindian populations, but a single trustworthy Native American prevalence number is not settled in the literature, so that point is kept qualitative.
Do the work
Explore (work the model before reading on)
- Out of every 700 babies born, about how many have some kind of ? Is that what you would call rare?
- Mateo has a lip AND together. What share of all clefts is that type? Is it the most common, middle, or least common type?
- Mateo is a boy, his is on one side, and it is on the left. For each of those three features, look up whether it matches the more common pattern or the rarer one.
- Rank the three ancestry groups from most to least affected. What does it tell you that the rate can differ by roughly fivefold (1 in 500 versus 1 in 2500) between groups?
- A colleague says Mateo's must be a rare bad-luck . Using the features you checked, predict whether Mateo looks like a rare outlier or the most typical cleft patient, and what that implies about whether one rare broken gene is the likely cause.
- In one sentence, what pattern did your team find about where Mateo falls in the population data?
The plan
Guided notes
1
How common, overall
Model start: is affected babies per total births; clefting is about 1 in 700, which is common.
- Epidemiology is the study of how often a disease happens and in whom; the key measure here is .
- Orofacial clefting affects about 1 in ______ live births worldwide, so it is one of the most common birth differences, not rare.
2
Patterns by type, sex, and side
- By type, the most common single type is cleft lip and together, about 45%, which is Mateo's type.
- By sex, the ratio is about 2 to 1, ______ to female; by , about 70% of one-sided clefts are on the ______ side, and Mateo's is left.
3
By ancestry and the breadcrumb
- Prevalence is highest in Asian and Amerindian groups, intermediate in European-derived, and lowest in African-derived; exact rates vary by study.
- Mateo matches the most common type, sex, , and side, which behaves like a common trait shaped by many small influences, not one rare broken gene.
Explore
Reading the Research
What to read
Read the title and the abstract only, not the whole paper. Dixon MJ, et al. 2011. Cleft lip and palate: genetic and environmental influences. Nat Rev Genet. [PMID:21331089]
Why this source matters
This is the published evidence behind today's idea: Mateo fits the single most common pattern in every category, which makes his cleft look common and patterned, not a rare random event.
Words to unlock first
epidemiologybirth prevalenceincidencesex ratiolaterality
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
You do not need the methods or statistics yet. If a sentence is about lab technique or math you have not learned, mark it and skip it.
Your output
Write one claim-evidence sentence: what this source claims, and the one piece of evidence that backs it up.
Where this fits
Tested on (Ohio WebXam)
Genetics of Disease · 072130
PLTW lesson
MI · Disease domain · Biomedical Innovations (BI), public-health and prevalence study design
WebXam domain
Bio-Molecular Technology
Evidence to produce
Write one plain-language paragraph for Mateo's parents answering how common a cleft like his is and whether he is a rare exception or a typical case, citing at least two specific numbers, plus one honest caution that exact ancestry rates vary between studies and a precise Native American figure is not settled.
Lab / skill
Clinical backbone (cleft team) · Clinical backbone (cleft team)
Explore
Vetted readings for this lesson
- Dixon MJ, et al. 2011. Cleft lip and palate: genetic and environmental influences. Nat Rev Genet. [PMID:21331089]
- Vyas T, et al. 2020. Cleft of lip and palate: A review. J Family Med Prim Care. [PMID:32984097]
- Salari N, et al. 2022. Global prevalence of cleft palate, cleft lip and cleft palate and lip. J Stomatol Oral Maxillofac Surg. [PMID:34033944]
The plan
Track your progress today
Check these off as you work through the lesson, then submit. This tells Mr. Mendoza how you're doing so he can help the class. It does not replace turning in your producible.
Use the code Mr. Mendoza gave you, not your name. Saved on this device.
Check off as you finish
- Read the Model and answered the Explore questions.
- Filled in the guided notes in my own words.
- Defined the new vocabulary with an example.
- Built the producible: Write one plain-language paragraph for Mateo's parents answering how common a cleft like his is and whether he is a rare exception or a typical case, citing at least two specific numbers, plus one honest caution that exact ancestry rates vary between studies and a precise Native American figure is not settled.
- Wrote my Claim, Evidence, and Reasoning exit ticket.
Pick your period and code first.
Check yourself
Exit ticket (Claim, Evidence, Reasoning)
- Claim: Mateo's is best described as a ________ (rare / typical) cleft.
- Evidence: The four population features I checked were ________, and each one matched the ________ (more common / rarer) pattern.
- Reasoning: A condition this common and this patterned across whole populations is unlikely to be ________, which points us toward studying many small influences rather than one rare event.
How this is graded (rubric)
For: Write one plain-language paragraph for Mateo's parents answering how common a cleft like his is and whether he is a rare exception or a typical case, citing at least two specific numbers, plus one honest caution that exact ancestry rates vary between studies and a precise Native American figure is not settled.
| 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. |
How the model answer scores against this rubric
- CompleteProficient: Nothing is left blank: the model fills every part of "Write one plain-language paragraph for Mateo's parents answering how common a cleft like his is and whether he is a rare exception or a typical case, citing at least two specific numbers, plus one honest caution that exact ancestry rates vary between studies and a precise Native American figure is not settled.".
- 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.
Explore
Where this leads: careers
Epidemiologist Public-health analyst Biostatistician
What's next: Mateo's fits the single most common pattern, which means it is not rare and not random. So what actually caused it: his genes, something in the pregnancy, or both?