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5.1 Case Study: Genes and Inheritance

Created by: CK-12/Adapted by Christine Miller

Case Study: Cancer in the Family

People tend to carry similar traits to their biological parents, as illustrated by the family tree. Beyond just appearance, you can also inherit traits from your parents that you can’t  see.

Rebecca becomes very aware of this fact when she visits her new doctor for a physical exam. Her doctor asks several questions about her family medical history, including whether Rebecca has or had relatives with cancer. Rebecca tells her that her grandmother, aunt, and uncle — who have all passed away — had cancer. They all had breast cancer, including her uncle, and her aunt also had ovarian cancer. Her doctor asks how old they were when they were diagnosed with cancer. Rebecca is not sure exactly, but she knows that her grandmother was fairly young at the time, probably in her forties.

Rebecca’s doctor explains that while the vast majority of cancers are not due to inherited factors, a cluster of cancers within a family may indicate that there are mutations in certain genes that increase the risk of getting certain types of cancer, particularly breast and ovarian cancer. Some signs that cancers may be due to these genetic factors are present in Rebecca’s family, such as cancer with an early age of onset (e.g., breast cancer before age 50), breast cancer in men, and breast cancer and ovarian cancer within the same person or family.

Based on her family medical history, Rebecca’s doctor recommends that she see a genetic counselor, because these professionals can help determine whether the high incidence of cancers in her family could be due to inherited mutations in their genes. If so, they can test Rebecca to find out whether she has the particular variations of these genes that would increase her risk of getting cancer.

When Rebecca sees the genetic counselor, he asks how her grandmother, aunt, and uncle with cancer are related to her. She says that these relatives are all on her mother’s side — they are her mother’s mother and siblings. The genetic counselor records this information in the form of a specific type of family tree, called a pedigree, indicating which relatives had which type of cancer, and how they are related to each other and to Rebecca.

He also asks her ethnicity. Rebecca says that her family on both sides are Ashkenazi Jews (Jews whose ancestors came from central and eastern Europe). “But what does that have to do with anything?” she asks. The counselor tells Rebecca that mutations in two tumor-suppressor genes called BRCA1 and BRCA2 , located on chromosome 17 and 13, respectively, are particularly prevalent in people of Ashkenazi Jewish descent and greatly increase the risk of getting cancer. About one in 40 Ashkenazi Jewish people have one of these mutations, compared to about one in 800 in the general population. Her ethnicity, along with the types of cancer, age of onset, and the specific relationships between her family members who had cancer, indicate to the counselor that she is a good candidate for genetic testing for the presence of these mutations.

Rebecca says that her 72-year-old mother never had cancer, nor had many other relatives on that side of the family. How could the cancers be genetic? The genetic counselor explains that the mutations in the BRCA1 and BRCA2 genes, while dominant, are not inherited by everyone in a family. Also, even people with mutations in these genes do not necessarily get cancer — the mutations simply increase their risk of getting cancer. For instance, 55 to 65 per cent of women with a harmful mutation in the BRCA1 gene will get breast cancer before age 70, compared to 12 per cent of women in the general population who will get breast cancer sometime over the course of their lives.

Rebecca is not sure she wants to know whether she has a higher risk of cancer. The genetic counselor understands her apprehension, but explains that if she knows that she has harmful mutations in either of these genes, her doctor will screen her for cancer more often and at earlier ages. Therefore, any cancers she may develop are likely to be caught earlier when they are often much more treatable. Rebecca decides to go through with the testing, which involves taking a blood sample, and nervously waits for her results.

Chapter Overview: Genetics

At the end of this chapter, you will find out Rebecca’s test results. By then, you will have learned how traits are inherited from parents to offspring through genes, and how mutations in genes such as BRCA1 and BRCA2 can be passed down and cause disease. Specifically, you will learn about:

• The structure of DNA.
• How DNA replication occurs.
• How DNA was found to be the inherited genetic material.
• How genes and their different alleles are located on chromosomes.
• The 23 pairs of human chromosomes, which include autosomal and sex chromosomes.
• How genes code for proteins using codons made of the sequence of nitrogen bases within RNA and DNA.
• The central dogma of molecular biology, which describes how DNA is transcribed into RNA, and then translated into proteins.
• The structure, functions, and possible evolutionary history of RNA.
• How proteins are synthesized through the transcription of RNA from DNA and the translation of protein from RNA, including how RNA and proteins can be modified, and the roles of the different types of RNA.
• What mutations are, what causes them, different specific types of mutations, and the importance of mutations in evolution and to human health.
• How the expression of genes into proteins is regulated and why problems in this process can cause diseases, such as cancer.
• How Gregor Mendel discovered the laws of inheritance for certain types of traits.
• The science of heredity, known as genetics, and the relationship between genes and traits.
• How gametes, such as eggs and sperm, are produced through meiosis.
• How sexual reproduction works on the cellular level and how it increases genetic variation.
• Simple Mendelian and more complex non-Mendelian inheritance of some human traits.
• Human genetic disorders, such as Down syndrome, hemophilia A, and disorders involving sex chromosomes.
• How biotechnology — which is the use of technology to alter the genetic makeup of organisms — is used in medicine and agriculture, how it works, and some of the ethical issues it may raise.
• The human genome, how it was sequenced, and how it is contributing to discoveries in science and medicine.

As you read this chapter, keep Rebecca’s situation in mind and think about the following questions:

• BCRA1 and BCRA2 are also called Breast cancer type 1 and 2 susceptibility proteins.  What do the BRCA1 and BRCA2 genes normally do? How can they cause cancer?
• Are BRCA1 and BRCA2 linked genes? Are they on autosomal or sex chromosomes?
• After learning more about pedigrees, draw the pedigree for cancer in Rebecca’s family. Use the pedigree to help you think about why it is possible that her mother does not have one of the BRCA gene mutations, even if her grandmother, aunt, and uncle did have it.
• Why do you think certain gene mutations are prevalent in certain ethnic groups?

Attributions

Figure 5.1.1

Family Tree [all individual face images] from Clker.com used and adapted by Christine Miller under a CC0 1.0 public domain dedication license (https://creativecommons.org/publicdomain/zero/1.0/).

Figure 5.1.2

Rebecca by Kyle Broad on Unsplash is used under the Unsplash License (https://unsplash.com/license).

Wikipedia contributors. (2020, June 27). Ashkenazi Jews. In  Wikipedia.  https://en.wikipedia.org/w/index.php?title=Ashkenazi_Jews&oldid=964691647

Wikipedia contributors. (2020, June 22). BRCA1. In Wikipedia . https://en.wikipedia.org/w/index.php?title=BRCA1&oldid=963868423

Wikipedia contributors. (2020, May 25). BRCA2. In  Wikipedia.  https://en.wikipedia.org/w/index.php?title=BRCA2&oldid=958722957

Human Biology Copyright © 2020 by Christine Miller is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License , except where otherwise noted.

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8.1: Case Study: Genes and Inheritance

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• Page ID 16760

• Suzanne Wakim & Mandeep Grewal
• Butte College

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Case Study: Cancer in the Family

People tend to look similar to their biological parents, as illustrated by the family tree in Figure \(\PageIndex{1}\). But, you can also inherit traits from your parents that you can’t see. Rebecca becomes very aware of this fact when she visits her new doctor for a physical exam. Her doctor asks several questions about her family's medical history, including whether Rebecca has or had relatives with cancer. Rebecca tells her that her grandmother, aunt, and uncle, who have all passed away, all had cancer. They all had breast cancer, including her uncle, and her aunt additionally had ovarian cancer. Her doctor asks how old they were when they were diagnosed with cancer. Rebecca is not sure exactly, but she knows that her grandmother was fairly young at the time, probably in her forties.

Rebecca’s doctor explains that while the vast majority of cancers are not due to inherited factors, a cluster of cancers within a family may indicate that there are mutations in certain genes that increase the risk of getting certain types of cancer, particularly breast and ovarian cancer. Some signs that cancers may be due to these genetic factors are present in Rebecca’s family, such as cancer with an early age of onset (e.g. breast cancer before age 50), breast cancer in men, and breast cancer and ovarian cancer within the same person or family.

Based on her family medical history, Rebecca’s doctor recommends that she see a genetic counselor because these professionals can help determine whether the high incidence of cancers in her family could be due to inherited mutations in their genes. If so, they can test Rebecca to find out whether she has the particular variations of these genes that would increase her risk of getting cancer.

When Rebecca sees the genetic counselor, he asks how her grandmother, aunt, and uncle with cancer are related to her. She says that these relatives are all on her mother’s side — they are her mother’s mother and siblings. The genetic counselor records this information in the form of a specific type of family tree, called a pedigree, indicating which relatives had which type of cancer and how they are related to each other and to Rebecca. He also asks her ethnicity. Rebecca says that her family, on both sides, are Ashkenazi Jews, meaning Jews whose ancestors came from central and eastern Europe. “But what does that have to do with anything?” she asks. The counselor tells Rebecca that mutations in two tumor-suppressor genes called BRCA1 and BRCA2, located on chromosome 17 and 13, respectively, are particularly prevalent in people of Ashkenazi Jewish descent and greatly increase the risk of getting cancer. About 1 in 40 Ashkenazi Jewish people have one of these mutations, compared to about 1 in 800 in the general population. Her ethnicity, along with the types of cancer, age of onset, and the specific relationships between her family members who had cancer indicate to the counselor that she is a good candidate for genetic testing for the presence of these mutations.

Rebecca says that her 72-year-old mother never had cancer, and nor had many other relatives on that side of the family, so how could the cancers be genetic? The genetic counselor explains that the mutations in the BRCA1 and BRCA2 genes, although dominant, are not inherited by everyone in a family. Also, even people with mutations in these genes do not necessarily get cancer — the mutations simply increase their risk of getting cancer. For instance, 55 to 65% of women with a harmful mutation in the BRCA1 gene will get breast cancer before age 70, compared to 12% of women in the general population who will get breast cancer sometime over the course of their lives.

Rebecca is not sure she wants to know whether she has a higher risk of cancer. The genetic counselor understands her apprehension but explains that if she knows that she has harmful mutations in either of these genes, her doctor will screen her for cancer more often and at earlier ages. Therefore, any cancers she may develop are likely to be caught earlier when they are often much more treatable. Rebecca decides to go through with the testing, which involves taking a blood sample, and nervously waits for her results.

Chapter Overview: Genetics

At the end of this chapter, you will find out Rebecca ’s test results. By then, you will have learned how mutations in genes such as BRCA1 and BRCA2 can be passed down and cause disease. Especially, you will learn about:

• How Gregor Mendel discovered the laws of inheritance for certain types of traits.
• The science of heredity, known as genetics, and the relationship between genes and traits.
• Simple and more complex inheritance of some human traits.
• Genetic Disorders.

As you read this chapter, keep Rebecca’s situation in mind and think about the following questions:

• What do the BRCA1 and BRCA2 genes normally do? How can they cause cancer?
• Are BRCA1 and BRCA2 considered linked genes? And are they on autosomes or sex chromosomes?
• After learning more about pedigrees, draw the pedigree for cancer in Rebecca’s family. Use the pedigree to help you think about why it is possible that her mother does not have one of the BRCA gene mutations, even if her grandmother, aunt, and uncle did have it.
• Why do you think certain gene mutations are prevalent in certain ethnic groups?

Attributions

• Caelius and Valerius family tree by Ann Martin , licensed CC BY 2.0 via Flickr
• Text adapted from Human Biology by CK-12 licensed CC BY-NC 3.0

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Genetics Case Study: Diagnose the Patient

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This task is heavily based on the work of others and is credited at the end.

For more excellent case study resources for science, visit the National Center for Case Study Teaching in Science .

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Interactive Case Study for The Search for a Mutated Gene

• Biotechnology
• Genetic Disease
• Experimental Design

Resource Type

• Interactive Videos

Description

This video case study explores the approaches scientists used to identify a mutation that causes retinitis pigmentosa (RP), a progressive disease that leads to blindness.

RP results in the deterioration of the retina and loss of vision. Some cases of RP are inherited and caused by mutations in one of several different genes. Many mutations that cause RP have been identified. But when scientists tested the DNA of the patient featured in this video, Sam, they did not find any of these known mutations. The video follows physician-scientist Edward Stone as he tried to uncover the mutation that causes Sam’s RP.

This video incorporates embedded questions at automatic pause points, where students are asked to make predictions, construct explanations, and analyze data. After answering all the questions, students can view their answers in a “Report” that can be printed. They can also add further explanation to each answer in the Report if their thinking has changed. The video can also be shown without embedded questions using "Presentation Mode." 

The “Resource Google Folder” link directs to a Google Drive folder of resource documents in the Google Docs format. Not all downloadable documents for the resource may be available in this format. The Google Drive folder is set as “View Only”; to save a copy of a document in this folder to your Google Drive, open that document, then select File → “Make a copy.” These documents can be copied, modified, and distributed online following the Terms of Use listed in the “Details” section below, including crediting BioInteractive.

Student Learning Targets

• Formulate a hypothesis to explain how a mutation in a gene would affect the function of a cell and an organism.
• Describe the possible steps involved in identifying a disease-causing gene mutation in a patient.
• Predict how replacing a mutated gene with a functioning copy of that gene will affect the phenotype of a cell and/or organism.
• Explain how the identification of disease-causing mutations can be used to develop medical treatments.  

Estimated Time

genetic disease, genomics, model organism, mutation, retinitis pigmentosa (RP), tRNA

Primary Literature

DeLuca, Adam P., S. Scott Whitmore, Jenna Barnes, Tasneem P. Sharma, Trudi A. Westfall, C. Anthony Scott, Matthew C. Weed, et al. “Hypomorphic mutations in TRNT1 cause retinitis pigmentosa with erythrocytic microcytosis.” Human Molecular Genetics 25, 1 (2016): 44–56. https://doi.org/10.1093/hmg/ddv446 .

Terms of Use

<p>Please see the <a href=" https://www.hhmi.org/terms-of-use&quot ; target="_blank">Terms of Use</a> for information on how this resource can be used.</p>

Accessibility Level (WCAG compliance)

Version history, curriculum connections, ngss (2013).

HS-LS1-1, HS-LS3-1, HS-LS3-3; SEP6

AP Biology (2019)

IST-1.K, IST-1.P, IST-2.E, IST-4.A; SP1, SP3

IB Biology (2016)

Vision and change (2009).

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Biology Teaching Resources

Resources for Teaching Genetics

Genetics includes the study of heredity, or how traits are passed from parents to offspring.   The topics of genetics vary and are constantly changing as we learn more about the genome and how we are influenced by our genes.

Inheritance Patterns and Punnett Squares

Notes and Slides on Mendelian Genetics – basic lesson to introduce genetics and probability

Simple Genetics Practice  – using mendelian genetics and Punnett squares

Peas, Please – practice setting up squares for basic Mendelian traits in pea plants ( Key, TpT )

How to Solve Dihybrid Crosses – step by step guide on setting up 4×4 squares and determining ratios

Advanced Bunny Genetic Crosses with two traits – also includes fruit fly genetics Bunny Genetics 2 – basic crosses, rabbits have gray or white hair, black or red eyes

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Genetics Practice Problems – crosses involving guinea pigs, goats, and pea plants; monohybrid and dihybrid crosses

Explore the Genetics of Corn Snakes – dihybrid crosses with corn snakes, color is polygenic

Blood Disorder Genetics – a worksheet with genetics problems that relate to specific disorders:  sickle cell anemia, hemophilia, and Von Willebrand disease.

Heredity Wordsearch – fill in the blank, find the words on a puzzle, basic vocabulary

Genetics Review Guide – focus on vocabulary, Mendel’s crosses, and practice genetics with Punnett squares

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Heredity Simulation – use popsicle sticks to show how alleles are inherited

Variations on a Human Face – toss a penny to determine the features of a face, such as freckles, dimples; then draw that face.

Paper Pets – another simulation using paper models with traits for eyes, nose, mouth, and hair.

Codominance, Multiple Alleles, and Sex-Linkage

Codominance and Incomplete Dominance – practice genetics on roan cows and pink flowers

Cow Genetics – roan coloration and horns, also includes a two-trait cross

Slides and Notes on Sex-Linked Genes

Fruit Flies and X-Linked Traits –  practice crosses that involve sex-linkage; fruit flies and calico cats

Sex Linked Traits – students practice doing crosses; tortoiseshell cats, colorblindness, and eye color in fruit flies

Drosophila (Fruit fly) Simulation – use a simulator to run crosses with flies to determine phenotype ratios and perform chi square analysis

Calico Cats and X Linked Traits – more practice with sex-linked traits, see also advanced version that goes into tortoiseshell vs calico

Why Are There No Male Calico Cats – case study and slide presentation that explore X inactivation and coat color in cats

Epistasis in Labrador Retrievers – explore the black (B_E_) , yellow (B_ee) , and brown (bbE_ ) color patterns in dogs

Sexy Chickens – inheritance patterns in birds, using the ZW sex determination concept

Blood Type Genetics – practice with blood type crosses and other ABO type alleles, multiple allele traits

Multiple Allele Traits in Chickens – shows how combs are inherited (rrpp x RRpp)

Frizzle Frazzled Chickens – incomplete dominance in feather types, with double dominant being unhealthy

How Do Genes Determine Skin Color? – this case study uses presentation slides to explore a real-life scenario where a Nigerian mother has two very fair skinned children.  

Design-a-Species – using the rules of inheritance (Mendel), create an organism; with dominant and recessive traits, multiple allele traits, and codominance

Genetics Project – Create a species and show how its traits are influenced by genetics

Genetics Overview for AP Biology – summarizes the various types of crosses students may encounter on the AP test

Genetics and Statistics

Hardy-Weinberg Problem Set – statistical analysis, using HW equation and some dragons

Hardy Weinberg Simulation – track an allele in population by simulating how parents pass alleles to offspring

Corn Genetics and Chi Square – statistical analysis, using preserved corn and counting kernels

Albino Corn Genetics – grow corn, 3:1 albino ratio, lab report analyzes F1, F2 crosses

Chi Square Modeling Using Candy  – count the number of each color in a bag to determine if they occur in equal proportions

Drosophila Virtual Lab – choose fruit fly parents and analyze offspring in this virtual lab

Genetics of Wisconsin Fast Plants – grow plants from seeds and analyze phenotype; perform chi square analysis

Human Genetics

Case Study – Cystic Fibrosis Mutations

Cystic Fibrosis and Cell Membrane Transport

SRY not SRY – case study on the sex determining region of the Y chromosomes

Case Study – How Do Genes Determine Skin Color

Analyzing Human Pedigrees

• Explore Inheritance Patterns of Sickle Cell Anemia
• Practice Pedigrees on Human Genetic Disorders
• Analyzing Human Pedigrees for AP Biology (includes sex linked traits)
• Exploring Autosomal Dominant Traits

Human Genetics Overview

Your Genes Your Choices  – this is a more involved group assignment where groups read scenarios about genetic testing and ethics involved.

Genetic Science Ethics  – survey as a group ethical questions involved genetics (cloning, gene therapy..)

Name the Gene – Explore Genes with BLAST – submit gene sequences to determine the related human trait

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41 5.1 Case Study: Genes and Inheritance

Created by: CK-12/Adapted by Christine Miller

Case Study: Cancer in the Family

People tend to carry similar traits to their biological parents, as illustrated by the family tree. Beyond just appearance, you can also inherit traits from your parents that you can’t  see.

Rebecca becomes very aware of this fact when she visits her new doctor for a physical exam. Her doctor asks several questions about her family medical history, including whether Rebecca has or had relatives with cancer. Rebecca tells her that her grandmother, aunt, and uncle — who have all passed away — had cancer. They all had breast cancer, including her uncle, and her aunt also had ovarian cancer. Her doctor asks how old they were when they were diagnosed with cancer. Rebecca is not sure exactly, but she knows that her grandmother was fairly young at the time, probably in her forties.

Rebecca’s doctor explains that while the vast majority of cancers are not due to inherited factors, a cluster of cancers within a family may indicate that there are mutations in certain genes that increase the risk of getting certain types of cancer, particularly breast and ovarian cancer. Some signs that cancers may be due to these genetic factors are present in Rebecca’s family, such as cancer with an early age of onset (e.g., breast cancer before age 50), breast cancer in men, and breast cancer and ovarian cancer within the same person or family.

Based on her family medical history, Rebecca’s doctor recommends that she see a genetic counselor, because these professionals can help determine whether the high incidence of cancers in her family could be due to inherited mutations in their genes. If so, they can test Rebecca to find out whether she has the particular variations of these genes that would increase her risk of getting cancer.

When Rebecca sees the genetic counselor, he asks how her grandmother, aunt, and uncle with cancer are related to her. She says that these relatives are all on her mother’s side — they are her mother’s mother and siblings. The genetic counselor records this information in the form of a specific type of family tree, called a pedigree, indicating which relatives had which type of cancer, and how they are related to each other and to Rebecca.

He also asks her ethnicity. Rebecca says that her family on both sides are Ashkenazi Jews (Jews whose ancestors came from central and eastern Europe). “But what does that have to do with anything?” she asks. The counselor tells Rebecca that mutations in two tumor-suppressor genes called BRCA1 and BRCA2 , located on chromosome 17 and 13, respectively, are particularly prevalent in people of Ashkenazi Jewish descent and greatly increase the risk of getting cancer. About one in 40 Ashkenazi Jewish people have one of these mutations, compared to about one in 800 in the general population. Her ethnicity, along with the types of cancer, age of onset, and the specific relationships between her family members who had cancer, indicate to the counselor that she is a good candidate for genetic testing for the presence of these mutations.

Rebecca says that her 72-year-old mother never had cancer, nor had many other relatives on that side of the family. How could the cancers be genetic? The genetic counselor explains that the mutations in the BRCA1 and BRCA2 genes, while dominant, are not inherited by everyone in a family. Also, even people with mutations in these genes do not necessarily get cancer — the mutations simply increase their risk of getting cancer. For instance, 55 to 65 per cent of women with a harmful mutation in the BRCA1 gene will get breast cancer before age 70, compared to 12 per cent of women in the general population who will get breast cancer sometime over the course of their lives.

Rebecca is not sure she wants to know whether she has a higher risk of cancer. The genetic counselor understands her apprehension, but explains that if she knows that she has harmful mutations in either of these genes, her doctor will screen her for cancer more often and at earlier ages. Therefore, any cancers she may develop are likely to be caught earlier when they are often much more treatable. Rebecca decides to go through with the testing, which involves taking a blood sample, and nervously waits for her results.

Chapter Overview: Genetics

At the end of this chapter, you will find out Rebecca’s test results. By then, you will have learned how traits are inherited from parents to offspring through genes, and how mutations in genes such as BRCA1 and BRCA2 can be passed down and cause disease. Specifically, you will learn about:

• The structure of DNA.
• How DNA replication occurs.
• How DNA was found to be the inherited genetic material.
• How genes and their different alleles are located on chromosomes.
• The 23 pairs of human chromosomes, which include autosomal and sex chromosomes.
• How genes code for proteins using codons made of the sequence of nitrogen bases within RNA and DNA.
• The central dogma of molecular biology, which describes how DNA is transcribed into RNA, and then translated into proteins.
• The structure, functions, and possible evolutionary history of RNA.
• How proteins are synthesized through the transcription of RNA from DNA and the translation of protein from RNA, including how RNA and proteins can be modified, and the roles of the different types of RNA.
• What mutations are, what causes them, different specific types of mutations, and the importance of mutations in evolution and to human health.
• How the expression of genes into proteins is regulated and why problems in this process can cause diseases, such as cancer.
• How Gregor Mendel discovered the laws of inheritance for certain types of traits.
• The science of heredity, known as genetics, and the relationship between genes and traits.
• How gametes, such as eggs and sperm, are produced through meiosis.
• How sexual reproduction works on the cellular level and how it increases genetic variation.
• Simple Mendelian and more complex non-Mendelian inheritance of some human traits.
• Human genetic disorders, such as Down syndrome, hemophilia A, and disorders involving sex chromosomes.
• How biotechnology — which is the use of technology to alter the genetic makeup of organisms — is used in medicine and agriculture, how it works, and some of the ethical issues it may raise.
• The human genome, how it was sequenced, and how it is contributing to discoveries in science and medicine.

As you read this chapter, keep Rebecca’s situation in mind and think about the following questions:

• BCRA1 and BCRA2 are also called Breast cancer type 1 and 2 susceptibility proteins.  What do the BRCA1 and BRCA2 genes normally do? How can they cause cancer?
• Are BRCA1 and BRCA2 linked genes? Are they on autosomal or sex chromosomes?
• After learning more about pedigrees, draw the pedigree for cancer in Rebecca’s family. Use the pedigree to help you think about why it is possible that her mother does not have one of the BRCA gene mutations, even if her grandmother, aunt, and uncle did have it.
• Why do you think certain gene mutations are prevalent in certain ethnic groups?

Attributions

Figure 5.1.1

Family Tree [all individual face images] from Clker.com used and adapted by Christine Miller under a CC0 1.0 public domain dedication license (https://creativecommons.org/publicdomain/zero/1.0/).

Figure 5.1.2

Rebecca by Kyle Broad on Unsplash is used under the Unsplash License (https://unsplash.com/license).

Wikipedia contributors. (2020, June 27). Ashkenazi Jews. In  Wikipedia.  https://en.wikipedia.org/w/index.php?title=Ashkenazi_Jews&oldid=964691647

Wikipedia contributors. (2020, June 22). BRCA1. In Wikipedia . https://en.wikipedia.org/w/index.php?title=BRCA1&oldid=963868423

Wikipedia contributors. (2020, May 25). BRCA2. In  Wikipedia.  https://en.wikipedia.org/w/index.php?title=BRCA2&oldid=958722957

Human Biology Copyright © 2020 by Christine Miller is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License , except where otherwise noted.

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Case Studies: Genetics & Heredity

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The Anti-Cancer Fight with the Wellness Menu

By Michelle Sue, Kenneth W. Yip

No Longer Long in the Tooth

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Can We Risk It Again?

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Those Who Wish to Sing Always Find a Song

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To Pick a Peck of Orange Peppers

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Metabolic Mayhem

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Computers and Micronutrients

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The Dutch Hunger Winter

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