UW PHG Final Exam Prep

HW1: Let's say that we are interested in the effects that social distancing has on other disease infectious besides coronavirus. Let's say hypothetically that we compare the self-reported "having a cold" (caused by rhinoviruses or one of four human coronaviruses) while watching lecture #2 between previous years PHG301 courses (which happened NOT during social distancing), to the PHG301 students who are taking the course now while social distancing measures are being implemented. Calculate the RR (relative risk or risk ratio) of having a cold during social distancing as compared to during pre-social distancing measures, and say in a sentence or two what that number means? (You don't have to show your work but doing so makes it easier to assign partial credit.)

(3/119)/(84/695)= RR RR= 0.208 or 0.21 The relative risk of 0.21 in this case indicates that under social distancing, students self reporting had less than 1/2 the risk of reporting a cold compared to not having a cold. had around .21 times the risk*

HW3: For schizophrenia, the prevalence in the general population is 1.2%. However, 13% of the full-siblings of diagnosed individual go on to develop schizophrenia themselves. What is λS, the sibling relative risk ratio, and what does it mean in words?

0.13/0.012=10.83 Relative risk in this case is how much higher the risk of getting schizophrenia is if you are a sibling of someone who has schizophrenia. Within this calculation the RR of 10.83 means that there is an 983% increased risk in full siblings of developing schizophrenia than there is in the general population.

HW1: If the calculation 2874/7878=0.365 is done, what is that reporting?

A proportion

HW7: How is ancestry analysis related to GWAS?

Ancestry analysis is necessary as a prerequisite for GWAS to include ancestry in the model as a potential confounder

HW3: Extra credit: Evolutionary biologist J.B.S. Haldane famously said, "I would lay down my life for two [siblings] or eight cousins." Going by amount of DNA shared by descent, as J.B.S. was doing here, how many nieces or nephews (or a gender-neutral term for a children of a sibling which we do not have in the English language) do you think he would sacrifice himself for? You should assume full sibling relationship.

4

HW7: What is the corresponding -log(p) that you should require a statistical significant association to meet or exceed on the Manhattan plot, to chance a 0.05 chance a false positive somewhere overall in a study with a million SNPs being genotyped? Give your number as a decimal.

7.3 (with margin: 0.1)

HW4: If a study estimates a heritability of 0.75 for Crohn's disease, what does that mean?

75% of the variation in the Crohn's disease trait in the population is attributed to differences in genetics

HW6: Which of the following kinds of disease genes could we help identify the location of through linkage analysis?

A mendelian major effect gene that is X-linked

HW5: If a gene is located on the recombining, homologous tips of the X and Y chromosomes, it will have the following inheritance pattern?

Autosomal

HW5: What is the most likely mode of inheritance for the shown pedigree? 5

Autosomal dominant

HW5: What is the most likely mode of inheritance for the shown pedigree? 6

Autosomal recessive

HW4: When monozygotic twins are not concordant, this can be because of...

Both A and B (Epigenetic factors resulting in different gene expression from the same genome and Environmental influences )

HW4: What is a difference between monozygotic and dizygotic twins that might violate the underlying environment assumption of twin studies?

Both of the above

HW1: 1. There have been recent studies that have suggested that breast cancer might be linked to different amounts of alcohol consumption. In each study scientists collected information about the women such as their diet, exercise, race, and smoking habits. Two possible studies were conducted: Study 1 Scientists grouped women between 55 and 70 into two groups - those with breast cancer and those without. Each group was asked about how much and what type of alcohol they consumed daily. Study 2 Two groups were created -women of ages 40 - 50 who drink alcohol regularly (at least 3 times per week) and those who do not. These two groups were followed for 20 years and observed for the development of breast cancer. What is the outcome being investigated for both of these studies that would go on the columns of the 2x2 table?

Breast Cancer

HW2: A topic in the news is coffee-drinking. A Japanese study examined the association between coffee consumption and the risk of a particular kind of cancer (endometrial endometrioid adenocarcinoma, or EEA). The researchers first identified 107 women less than 80 years of age from two medical centers who had been diagnosed by cell staining to have EEA. From a cancer-screening program they also identified 214 women who did not have EEA, who were matched for age and for area of residence for the EEA patients. A questionnaire containing questions to determine past beverage consumption was administered, including questions about coffee consumption. What kind of study is this?

Case-Control

HW6: Which of these markers is perfectly linked to the disease in the family from the previous question? (Note that an uninformative marker has been removed from the list.) Select all that apply.

D1S515 D1S2806

HW3: There are standardized notations for pedigrees that have been completely implemented in the major health history toolkits that cover all types of family building, including third-party assisted reproduction and half-sibling twins.

FALSE

HW1: The UW Seattle student body autumn quarter doesn't count as a population because the students are no longer in geographic proximity to one another (because some students are taking the class in other cities, states and countries).

False

HW1: The only multiplier used in rates in epidemiology is 100 for percentages.

False

HW2: Causes in epidemiology must be necessary and sufficient

False

HW2: If an odds ratio for the association between exposure and disease is statistically significant and much bigger than 1, this means that the exposure must be directly causing the disease outcome.

False

HW4: Everyone who has a recessive disease allele must always carry exactly the same nucleotide variant, so there's a simple genotype test for whether they have it or not.

False

HW5: Hallmarks of mitochondrial inheritance include only females being affected because only females have mitochondria.

False

HW5: It is always possible to infer genotype from phenotype.

False

HW7: Ancestry is synonymous with race.

False

HW4: The incidence of testicular cancer in Sweden is over double the rate in Finland. When Finns in their twenties move to Sweden, their testicular cancer risk remains at the Finnish level, but their sons have the Swedish testicular cancer rate. (This is true even if they marry Finnish women so the sons are ethnically 100% Finnish.) What does that mean?

Evidence for environmental etiology of early childhood exposure

HW4: An adoption study finds that adoptees who have at least one genetic (birth) parent with coronary heart disease were 1.5 times more likely to develop coronary heart disease themselves than adoptees without a genetic parent with CHD. However, adoptees with at least one adoptive parent with CHD were not at increased risk for developing the disease themselves. What does that mean?

Evidence for genetic etiology

HW3: Considering genetic relatives only, full siblings are first degree relatives, parents/children are first relatives, and grandparents/grandchildren are second degree relatives. (Answers may be used more than once or not at all.)

First, First, Second

HW3: Extra credit: the below item is on sale on Ebay as a "Bone cell Osteon Biology Science STEM" print-dress. (Listing still active at time of publishing this homework, for those who are a size small.) Assuming you watched the genetics tutorial lecture, you should disagree with the listing description. What's a better short description for the Biology Science STEM concept that is actually being showcased on this skirt?

Franklin's DNA Crystal

HW7: A customer who obtained different results from three different ancestry testing companies is upset, and wants his money back, because he thinks it's ridiculous that his y chromosome and mitochondrial DNA tests do not match up with the results he got for his autosomes. What do you say in response?

He shouldn't get his money back; these tests are reporting different information about different lineages of his ancestors

HW1: Do you think epidemiology is a science? Give a brief answer and explain why.

I do think that epidemiology is a science. I see epidemiology playing a large part in systematic approaches to collecting and analyzing data in large scale especially when it comes to diseases and transmission. I've had some experience in health care and medicine and I definitely think epi has unique thought processes and methodologies involved in its study.

HW1: A survey is conducted to investigate knee pain in senior citizens. It gets 7878 respondents and 2874 of them reported having had knee pain in the past month. Is this study looking at prevalence or incidence of knee pain?

Prevalence

HW2: You are excited to find a nice robust association! However, your classmate provides the criticism, "but what if the reason people aren't employed is because they're depressed?" This would be an instance of:

Reverse-time order

HW1: Match the kind of epidemiology with what it studies

Looks for patterns in disease distribution to generate hypotheses - Descriptive Epi Compares groups to test hypotheses about what might be causing/determining a disease - Analytic Epi studies how genes and environmental factors cause disease in human population and families - Genetic Epi

HW5: Complex traits are complex because:

Many different genes contribute to the final phenotype Environmental factors contribute to the final phenotype Interactions between genes and environment can contribute to the phenotype Gene-gene interactions can modify the final phenotype All of the above are reasons

HW5: What is the most likely mode of inheritance for the shown pedigree? 3

Mitochondrial

HW4: Briefly define p-hacking, why it's a problem and describe one potential solution.

P-Hacking is the manipulation of findings and subgroup analysis in order to find an association. This is an issue because it doesn't accurately illustrate the research and data it is depicting. It seems it is more so manipulating data so it shows what you want it to show to your audience. One solution to this method would be setting parameters to your study/research early so that you are manipulating data as you go. Set boundaries and stick to it.

HW3: Having a family history is a risk factor for developing most diseases.

TRUE

HW3: Potential bias exists in family aggregation studies around patients/cases being more motivated to respond or better informed as a result of their disease status.

TRUE

HW3: For the pedigree shown, what is the relationship between individuals 3 and 4?

Siblings

HW2: Assuming that your result from the previous question reaches statistical significance, what does that number from the previous question mean about the relationship between exposure and disease?

The exposure is protective for the disease

HW4: Match the study with what calculations/information you get out of it. Not all answers must be used, answers may be used more than once, and there may be more than one correct answer - you only have to give one.

Twin studies - heritability Adoption of migrant studies - heritability Segregation analysis - statistics about which model is the best fit for the mode of inheritance Familial aggregation studies - odds ratio or RR association

HW5: What is the most likely mode of inheritance for the shown pedigree? 2

X-LINKED recessive

HW5: Note that a question like this will not be present on the final, it's fair game only because you have notes and instructor powerpoints to refer to. :) What is the most likely mode of inheritance for this pedigree, noting that Edith (I:2), Mary (II:2) and Alison (III:4) all had a number of recurrent late-term miscarriages and stillbirths, in addition to the children noted on the pedigree. (Those miscarriages/stillbirths were all male.)

X-linked dominant

HW5: What is the most likely mode of inheritance for the shown pedigree? 4

X-linked dominant

HW5: Sex chromosomes. . . .

are passed down differently from autosomes because they determine the biological sex of offspring

HW5: Obesity, like many complex human traits, is a _________ trait.

both (multifactorial and polygenic)

HW6: In the picture accompanying the previous question, the red arrows indicate (select all that apply)...

crossing over events took place during meiosis in their mother that individuals 53 and 55 represent recombination events which can help us narrow down the region of linkage

HW7: GWAS usually identifies....

multiple SNPs in linkage disequilibrium at each disease-involved location in the genome

HW6: Which of the following is true about the TAS2R38 gene?

the different common alleles in humans are separated from each other by multiple amino acid substitutions

HW4: Which of the following is true about twins?

there are twins that are neither dizygotic nor monozygotic

HW2: Which type of study design is best suited for each of the following scenarios?

Generating new hypotheses about disease distributions (not testing them) - Descriptive Epi Establishing causation with the greatest scientific validity, when ethically feasible to expose subjects and ample funding exists - Experimental Trial Being quick and cheapest to conduct - Cross-Sectional Study Looking at a very rare disease, to investigate many exposures - Case-Control study Following the incidence of disease resulting from exposure in correct time-order, when the exposure is not ethical to assign - Cohort Study

HW4: How can anyone (scientists, curious relatives, twins themselves) reliably tell whether twins are monozygotic, dizygotic full-sibling twins, dizygotic half-sibling twins, or sesquizygotic?

Genetic Testing

HW4: For the following genetic epidemiological questions, indicate the type of study that addresses it.

What is the disease, how is it distributed (in people, time, place)? - Descriptive Epi Does it cluster in families (or run in families)? - Familial Aggregation Is there a genetic effect (heritability)? - twin/adoption In what pattern is the disease inherited from parent to offspring? (I.e. is it passed on like there's one gene or many, dominant or recessive, autosomal or sex linked or other?) - segregation analysis

HW3: Pedigrees (graphical displays of family health history) and the data about genetic relationships that they display can be used in...

All of the above

HW3: In a study of familial aggregation, the risk of psoriasis (an autoimmune skin condition) was evaluated in first degree relatives of people with psoriasis, as compared to people who did not have a first degree relative with psoriasis, using a cohort approach. The RR was 5.5. Which, if any, of the following statements are NOT a correct interpretation of that RR in plain English?

All of the above are correct interpretations

HW3: Most clinicians have dedicated time to take a family health history and document it for you in a summary figure, so individuals don't need to collect their own.

FALSE

HW3: For the pedigree shown, what is the relationship between individuals 1 and 2?

Mating

HW5: PKU is an autosomal, recessive condition caused by mutations in the PAH gene. However, individuals only develop the trait when they are exposed to dietary phenylalanine. PKU is thus a _____ trait.

Multi factorial

HW6: The markers which are transmitted along with the trait of interest in the family in the previous question:

Must be physically nearby the disease gene on the same chromosome

HW2: What is the answer you get when you calculate the number from the previous question? Correct!

O.42/0.416

HW1: Disease outcomes may be determined by which causes?

One or more of the above factors above acting together

HW3: If a trait is shown to have familial aggregation, what does that mean?

The trait could be attributed to either genetics OR environment

HW3: Which of the following is NOT a correct way to describe a RR of 0.66?

The risk is reduced BY two thirds.

HW1: I may discuss this homework/canvas quiz with my classmates, as long my final submission represents my own understanding and words. (This information is found in the syllabus.)

True

HW3: Familial aggregation studies can take both a case-control and a cohort study approach.

True

HW4: If unaffected people mating with each other have affected offspring, that suggests recessive inheritance of the trait.

True

HW5: To do a segregation analysis involves collecting the same data as familial aggregation studies (pedigrees and phenotypes), just analyzing them differently (fitting to different models of inheritance).

True

HW6: Which of the following is true about PTC taste ability? Check all that apply, noting that the answers are covered roughly in lecture order.

it is testing the ability to taste a synthetic chemical discovered in a lab accident it is relevant to goiter development in some environments it has been hitched to questionable eugenic messaging it is functionally related to more robust infectious disease in the innate immune response it is associated with decreased risks of colorectal cancer it is associated with decreased risk of neurological diseases like Parkinson's and schizophrenia it is associated with decreased pediatric cavities it is associated with increased longevity it is inversely related to ability to detect other foods as bitter it mediates cruciferous vegetable taste perception and influences diet it is associated with lower alcohol use and smoking it is associated with COVID disease progression is determined by the action of at least two genes but also environmental factors it is variable in almost all human populations it is one of the most studied traits in human genetics might be associated with a lower risk of BMI extremes, even if the genetic variants in the TAS2R38 gene aren't

HW6: Match the pedigrees with the mode of inheritance:

(hw6 q1) family a- mitochondrial family b- autosomal dominant family c- y-linked family d- x-linked recessive family e- x-linked dominant family f- autosomal recessive

HW6: What statement is correct logic about the inheritance pattern for the trait represented on the pedigree below? (Shaded individuals, both grey and black, are affected, but the darker shading is for individuals who enroll in the study.)

(hw6 q2) Autosomal because a father can transmit to some of his sons and daughters

HW6: For the pedigree shown, answer the questions below. 1. What is the best possible mode of inheritance for this pedigree, from a linkage study of a blood disorder? Note that individuals with a dot (rather than completely filled in) are designating unaffected carriers. X-linked recessive 2. Among those listed (only), which marker is perfectly linked to the disease? DXS8054 (the marker which has allele 2 on the disease haplotype in this family)

(hw6 q6) X-linked recessive DXS8054 (the marker which has allele 2 on the disease haplotype in this family)

HW6: For the pedigree of microcephaly (small brain) shown, answer the questions below. 1. What is the best mode of inheritance? (Note that the places in pedigree 1 where the lines are curvy is to be able to depict the consanguinity in this family: where two siblings in generation V are married to their first cousins and one sibling is married to a more distant cousin.) Autosomal recessive 2. Which markers are perfectly linked to the disease in both of these families? D8S1798, D8S277, D8S1819 3. There are multiple genes surrounding the marker(s) you selected in the previous question. How do you best identify which one is the disease gene? Sequencing looking for homozygous variants near these markers 4. Let's say the LOD scores from these two families put together are less than -4 at markers D8S504 and D8S1824. What does that mean? The disease gene is excluded from being at those markers 5. What does it mean that the LOD score is 5.75 for markers D8S1798, D8S277 and D8S1819? Probability of these markers being linked to the disease gene is more than 100000 times greater than the probability of being unlinked

(hw6 q7) 1- Autosomal recessive 2- D8S1798, D8S277, D8S1819 3- Sequencing looking for homozygous variants near these markers 4- The disease gene is excluded from being at those markers 5- Probability of these markers being linked to the disease gene is more than 100000 times greater than the probability of being unlinked

HW7: You are a principal invesigator designing a GWAS to study your favorite health-related trait. Choose which of these QQ plots would be most desirable to obtain at the end of your GWAS study, to show that you had obtained meaningful results (SNPs associated with your trait of interest) with a minimum of bias or confounding.

(hw7 q3) d

HW7: On the following Manhattan plot, which you generate for your study, which association(s) would you be excited about having identified? 1. Select the gene name(s) FTO and TCF7L2 . Note that the -log(p) value for the gene FTO is 7.5. 2. If you wanted to see if there was truth to of the other peaks in the Manhattan plot NOT identified by you in the previous answer, what could you do? Add more subjects (cases and controls) to increase power 3. Below is another Manhattan plot for a classmate's GWAS genotyping 1 million SNPs. (Note: the highest Y value of any point on this plot is below 7.) How would you best interpret it? I'd not be very excited - nothing meets the cutoff for significance.

(hw7 q5)- two pics 1- FTO and TCF7L2 2- Add more subjects (cases and controls) to increase power 3- I'd not be very excited - nothing meets the cutoff for significance.

HW7: Going back to check out the genotype quality for the SNPs you identified as relevant, which would be the more desirable clusterplot that would create confidence in your genotyping and allow you to conclude that you had a result you could publish?

(hw7 q6) e

HW3: What number do you get from the previous question?

2.27

HW1: From the previous question, how would you describe the calculation 598 new cases/31000 students/3 months of autumn quarter, or 0.006 cases/student/month. or 300 cases/100k students/fortnight?

A rate

HW5: Why does your teacher not have you look at your own and classmates' cheek cells with stains to see inactivated X chromosomes in females and a lack of inactivated X chromosomes in males?

Because sex chromosome aneuploidies are fairly common and that might be upsetting to find out, and biological sex isn't always the same as gender and outing people would be rude

HW2: Expanding upon the study information given in the previous question, there were 571 participants that had historically eaten a high fiber diet, and 86 of them had restricted airways. There were 309 interviewees who had historically not eaten a high fiber diet, and 92 of them had restricted airways. For this study, can you calculate a RR (0.5)? If so, calculate it (1 pt) and say if the exposure is protective or a risk factor (.5 pt). If not, explain why you are not able to (1 pt) and what you should calculate instead (.5 pt).

Cohort studies CAN calculate a RR! Your number should be something along the lines of 0.50586309297234, meaning that those who ate a high fiber diet were only half (or 0.51x) as likely to have restricted airways as those who did not eat a high fiber diet.

HW2: Your instructor reads this paper and says, "Well, everyone I know who is eating a high-fiber diet rich in fruits and vegetables is also really preoccupied with being healthy in other ways, like exercising regularly. What if it's the exercise that is truly causative in improving lung health?" What explanation does this suggest for the association found?

Confounding

HW2: You are interested in whether underemployment is a risk factor for depression, but as an undergraduate student you are limited in funds, so you decide to conduct a study by simply conducting a phone/internet survey in which people self-report the exposure (underemployment) and outcome (depression) at that point in time. What kind of study is this?

Cross Sectional

HW7: What kind of study would be best/cheapest way to identify the genetic risk alleles for a common disease, which you believe (from segregation analysis) to be polygenic in nature?

GWAS

HW1: For the following list of activities that an epidemiologist might perform, decide which part of the definition of epidemiology is being addressed: distribution, determinants, or application. Hint: you might want to think about whether something is descriptive epidemiology (then it is describing the distribution of the disease), analytic epidemiology (then it is trying to discern the determinants of the disease), or guiding health services/programs (then it is an application of epidemiology to improve public health).

Graph the number of cases of congenital syphilis by year for the country - Distribution Compare frequency of brain cancer among anatomists (who are exposed to many chemical exposures professionally, i.e. stains and fixatives) with frequency in general population - Determinants Recommend that close contacts of a child recently reported with meningococcal meningitis receive Rifampin - Application

HW3: You are equally closely related with a first cousin as with a...

Great-grandparent

HW4: An article you found for discussion section is reporting a number that the authors describe as "the proportion of variation in a trait that is attributable to variation in genetics". The article gives a number that's between 0 and 1. However, the article doesn't actually give a specific term for this test statistic, so a fellow student is confused about how this number relates to class concepts. You help your fellow student and explain that the study is giving the...

Heritability

HW2: A cohort study of 880 study participants that came out earlier this week looked for an association between exposure to a high-fiber diet (as measured by a survey) and then following up over time on lung problems as measured by airway restriction.

In this study, LUNG PROBLEMS is the disease outcome and HIGH-FIBER DIET is the exposure?

HW1: Say we look at the UW dashboard for COVID to look at new cases of COVID-19 disease during the previous quarter, and we discovered that 598 students enrolled through the Seattle campus contracted COVID-19 during autumn quarter. (We did not count students who started the quarter with a preexisting COVID19 case, or who had it earlier in the year but recovered.) Would looking at these new cases that arose be looking at incidence or prevalence?

Incidence

HW2: The Doll and Hill case-control study we talked about in class investigated the smoking history of patients hospitalized in London for lung cancer as well as age-matched controls who were hospitalized for other causes. If we use their overall results (both genders grouped together) to calculate an odds ratio, as we did in class, we get an odds ratio (OR) of 3.0. What is the best, most complete interpretation of what this OR means, in English? (Note: one of these interpretations is using language that is more directly describing an RR. Since the OR often approaches the RR for rare diseases, such that they might not be numerically very different, that is not unreasonable, but it is not the BEST answer.)

Lung cancer patients were 3 times more likely to have been smokers than patients hospitalized for other causes

HW4: If monozygotic twins have a concordance of 28% for Irritable Bowel Syndrome, and dizygotic twins have a concordance of 27%, what does that suggest? (Note that these are real numbers from an actual study, and if asked to describe the meaning of the 1% difference I would say they are very similar.)

Mostly Environmental etiology

HW4: If monozygotic twins have a concordance of 96% (super close to 1!) for recurrent childhood ear infections, and dizygotic twins have a concordance of 51% what does that suggest? Note these are real numbers so you will need to decide which of these is the BEST model to explain the data, not the most perfect one.

Mostly Genetic Etiology

HW5: Which of these is a mode of inheritance that we look for on pedigrees?

None of the above; Y chromosomes are hemizygous and mitochondria are all inherited from one parent, so it doesn't make sense to think about multiple alleles together for those genes

HW2: Of the 107 women with EEA, 29 drank multiple cups of coffee on an average day. Of the 214 women without EEA, 101 drank multiple cups of coffee on an average day. For this study type, what is the appropriate calculation to measure the strength of association between coffee intake and EEA?

OR

HW3: The role of family history as a risk factor of coronary heart disease was explored in a study of 121 female survivors of a recent heart attack and 130 control women (selected to be good matches for the survivors in age, ancestry, and neighborhood residence). Each woman was asked whether she had first-degree relatives (parents or siblings) who had occurrence of CHD. Here is the collected data: Survivors of recent heart attack Control women Total Family history of CHD in first degree relative (parent/sibling) 21 11 32 No family history of CHD in first-degree relatives 100 119 219 Total 121 130 251 subjects What calculation is appropriate to do to assess the role of family history as a risk factor given this study design?

Odds Ratio

HW3: For the pedigree shown, what is the relationship between individuals 1 and 4?

Parent-Child

HW2: A hypothetical study is seeking to look at the exposure of noise pollution and its impact on the disease of heart disease. Heart disease No heart disease High levels of noise pollution 232 648 Low levels of noise pollution 315 1008 What is the relative risk (or risk ratio) for heart disease in high levels of noise pollution as compared to areas of low noise pollution? Please give the answer to at least two decimal places, like 1.00 (rounding is okay), and then say in your own words (in plain English) what it means.

RR= 1.11 The relative risk of 1.11 means that there is a 11% increased risk of heart disease when there is high levels of noise pollution.

HW7: When a strong, statistically significant association between a SNP and disease is identified via GWAS, and confirmed by multiple independent, well-designed studies (good quality control measures, good control choices, lack of population stratification), what conclusions should be drawn?

The actually causative SNP might be in linkage disequilibrium (very very close on the same chromosome) with the causative variant

HW1: The INTERPHONE study looked at cell phone use among more than 5,000 people who developed brain tumors and a similar group of people without tumors. Overall, the study found no link between brain tumor risk and the frequency of calls, longer call time, or cell phone use for 10 or more years. There was a suggestion of a possible increased risk of small tumors, in the 10% of people who used their cell phones the most. But this finding was difficult to interpret because of some people reporting implausibly high cell phone use.

What is an exposure being tested in this study? (Note there may be multiple correct answers) - Cell Phone Use What is the disease outcome? Brain tumor

HW5: What is the most likely mode of inheritance for the shown pedigree? 1

Y-linked