Greg and Olga Case Study about affected X genes

For the past couple of days in Biology we have been working on a case study of the couple: Greg and Olga. We had to create a pedigree and answer questions from the site. If you would like to read about this case study the link is posted below.

Case Study:
http://www.sciencecases.org/sickness_and_health/sickness_and_health.asp

Like I said above, we had to create a pedigree based on what Greg and Olga told us about their families. To take a look at the pedigree I've created please follow the link below.

Greg and Olga Pedigree:
https://docs.google.com/drawings/d/1FhE6MxCduJgiw27bxoyte5Diw0TkteDKBJBJ9MlS6tg/edit

After we created the Pedigree we had to answer questions. The questions were pretty easy to answer once the pedigree was finished. Below are the Questions from pages 1-4 and my answers. I've colored the questions in green and my answers in blue.

Questions:

1)   What would a pedigree of Greg and Olga’s families look like? Concentrate simply on family relationships and affected persons.

https://docs.google.com/drawings/d/1FhE6MxCduJgiw27bxoyte5Diw0TkteDKBJBJ9MlS6tg/edit 

2)   Do autosomal dominant disorders skip generations?

Yes. In Olga’s side of the family it skipped generations but in Greg’s side it skipped but his brother ended up with hemophilia insteas of mytonic dystrophy (MD).

3)   Could Greg or his mother be carriers of the gene that causes myotonic dystrophy?

It is possible that Greg’s mom could be a carrier for (MD) because her sister and brother contain a gene. Greg on the other hand probably not because neither his sister or brother contain the (MD) gene but his brother has the Hemophilia gene.

4)   Is there a possibility that Greg’s aunt or uncle is homozygous for the myotonic dystrophy (MD) gene?

There is a possiblitity that Greg’s aunt and uncle could be homozygous for containing the gene. Their parents don’t but they could.

5)   Symptoms of myotonic dystrophy sometimes don’t show up until after age fifty. What is the possibility that Greg’s cousin has inherited the MD gene?

Greg’s cousin has a 50% probability of having the MD gene since her mother carries it.

6)   What is the possibility that Greg and Olga’s children could inherit the MD gene?

The possibility that their child can inherit the MD gene is 0% because Greg is not a carrier of the MD gene and neither is Olga.

7)   What are the hallmarks of an autosomal recessive trait?

The hallmarks of an autosomal ressive trait are in almost every family member because both parents do not have the gene only one parent does.

8)   What does consanguineous mean? Why is this concept especially important when discussing recessive genetic disorders?

Consanguineous means having the same ancestry or descent; related by blood. This concept is important because Greg and Olga could carry the same gene without even knowing it.

9)   What is it about the inheritance pattern of factor VIII deficiency seen in Greg and Olga’s pedigree that point toward it not being an autosomal recessive trait?

The pattern of factor VIII (Hemophilia) skips a generation and in Greg’s family it was only contained by his brother.

10)               What are the characteristics of X-linked recessive inheritance?

The characteristics can sometimes be only found in males who have inherited a ressive X-link mutated from their mother.

11)               Why does a son never inherit his father’s defective X chromosome?

If the baby is going to be a son he can recive and X from his mother but in order to be a boy the son needs to receive a Y from the father because the male only carries XY and females carry XX. If the baby were to receive a defective X chromosome from his father then the baby would be a girl because the mom can only give and X.

12)               What is required for a woman to display a sex-linked recessive trait?

For a woman to display an X-linked recessive trait, she would need two mutant copies of the X-chromsome--one from both parents.

13)               Return to the pedigree drawn earlier for Greg and Olga; mark those persons who are carriers of the factor VIII deficiency gene.

The people who are marked for the Factor VIII definiency gene are the ones marked in yellow.

14)               What is the chance that Olga carries the gene for factor VIII deficiency? Calculate the probability that she will pass it to her offspring. Will male children be affected in a different way than female children?

Olga has a ¼ chance of carrying the gene of Factor VIII. Therefore she has a ¼ chance of passing it to her offspring. The male child has a 1/8 chance of being affected or of being a carrier. It is the same change for female children.

15)               What is the chance that Greg carries the factor VIII gene? Can he pass the gene on to his sons? His daughters? How will each be affected?

Factor VIII is carried by an X chromosome so there is no chance that Greg has the affected gene. He can not pass it to his son because he must pass a Y chromosome inorder to have a son. For his daughter, she can not be affected because he carries the unaffected X chromosome. 

Pedigree for Blue Skinned People

For the past week in Biology we have been working on pedigrees. Our first pedigree was the paper test. Our second pedigree is on the blue skinned people. We had to read through an article about them and figure out a pedigree for them. If you would like to read the article, I posted the link below. The article is quite interesting I urge you to take a peek.

http://abcnews.go.com/Health/blue-skinned-people-kentucky-reveal-todays-genetic-lesson/story?id=15759819#.T0fPt1G5Lao 

Anyway after reading the article I created what I think is their pedigree. I know the names of the parents and Benjamin's family but I'm sorry I did not know the children's names. If you would like to take a look at the created pedigree please follow the link below.

https://docs.google.com/drawings/d/1ij1o11PltDTQ1uXj930Bta-PwBHMmk-iZ53P59rgt7Y/edit

Family Pedigree

Below is a Family Pedigree chart that I made of my family that shows who are tasters. By using tasting paper. From the looks of the pedigree the tasting trait is most dominate in the females of my family. So I think it has more to do with the sex.

THE HUMAN GENOME AND GENETIC DISEASE WEBQUEST

In 2001, the Human Genome Project completed the sequencing of the entire human genome. A byproduct of this effort was the identification and mapping of more than 1,000 human disease genes. The large amounts of data generated by the Human Genome Project have been organized and made available to scientists and the general public via several databases. Online Mendelian Inheritance in Man (OMIM) is one example. OMIM is a catalog of human genes and genetic disorders developed for the World Wide Web by the National Center for Biotechnology Information (NCBI). The database contains information about the research history of the disease gene, inheritance patterns, a clinical synopsis of the disorder, and information about the molecular nature of the mutation or defect that leads to the disorder.

Activity

In this activity you will access the resources provided by the National Center for Biotechnology Information and research the details of a genetic disease using OMIM.

Part 1

Use your browser to go to

http://www.ncbi.nlm.nih.gov/

http://www.ncbi.nlm.nih.gov/

Under the section "Genetics and Medicine" choose "Genes and Disease."

Choose the section near the bottom titled Chromosome Map and read the introduction to chromosome mapping.

*What are the three main parts of a chromosome, as viewed under a microscope? 

      a.Three main parts of a chromosome when viewed under a microscope are two special chromosomes, X and Y, that determine our sex, special units of chromosomal DNA, and the center of each chromosome, centromere.

It will be handy to know these as you are looking at maps of chromosomes- these will be part of the “address” for each gene!

Select the X chromosome from the list of chromosomes on the right side of the page and read the summary of the genes found on the X chromosome.

*List at least four human diseases that have been mapped to the X chromosome.

      a.Hemophilia

      b.Alport Syndrome

      c.Menkes Syndrome

      d.Fragile X Syndrome

Click on the Map Viewer link at the very bottom of the page (Featured: Mapviewer)or click here:http://www.ncbi.nlm.nih.gov/mapview/

http://www.ncbi.nlm.nih.gov/mapview/

Notice that this database has information about the DNA and proteins for many species (including platypus!).

Choose the latest build for human (homo sapiens) chromosomes.

Select the X chromosome.

At this point you will be looking at the most current map of the known DNA sequences on the human X chromosome! And yes, its complicated  : )

You can browse through the map of the X chromosome if you wish, zooming in and out. You may find the “You are here:” diagram on the left side of the page to be handy (or not).

Perhaps an easier way to experience the map of the X chromosome is to do a search for one of the disease genes that you discovered earlier. Do that now using the search box above the chromosome map.

Once you get the results, click on the Map Element that looks most promising to you. This link will take you to a more detailed map of the X chromosome showing where the disease gene is located.

Click on one of the reference numbers for that gene to see if you can get some useful information about it (and there will be a lot of scientific nonsense, so keep digging or find a summary!)

*Read the summary section for that gene to find out what functions, processes, and components it is thought to be involved in (what’s it do?).  

Part 2

Hemophilia A

a.Function:  a deficiency of the blood clotting protein known as Factor VIII that results in abnormal bleeding.

b.Process: Mutation of theHEMA gene on the X chromosome causes Hemophilia A.

c. Components: X-linked disorders such as Hemophilia A are far more common in males. The HEMA gene codes for Factor VIII, which is synthesized mainly in the liver, and is one of many factors involved in blood coagulation; its loss alone is enough to cause Hemophilia A even if all the other coagulation factors are still present.

Return to the Genes and Disease table of contents where you began this exercise (http://www.ncbi.nlm.nih.gov/books/NBK22183/).

Choose a topic from the menu at the left (Cancer, Immune System, Metabolism, and so on).

Read the introduction to the disease type you have chosen, then choose a specific disease to study.

Read the information about the disease you picked and use it to answer the following questions:

*What disease did you choose and what gene is/genes are associated with this disease?

      a.The disease that I chose is called Rett Syndrome. The genes that are associated with RTT are mutations in the gene MeCP2

*On what chromosome are these genes/is this gene located?

      a.Found on the X chromosome.

Use the link at the side of the disease page to go to the OMIM entry for the disease you chose.

*Read the text section and the clinical synopsis in the OMIM entry and answer the following questions:

• When was the disease first reported in the scientific literature?

·       Rett , a Viennese pediatrician, first described Rett syndrome after observing 2 girls who exhibited the same unusual behavior who happened to be seated next to each other in the waiting room. (Around 1966-1977)

• What are some of the clinical symptoms of this disease?

·       a period of clear developmental regression followed by limited recovery or stabilization. Other main criteria include loss of purposeful hand skills, loss of spoken language, gait abnormalities, and stereotypic hand movements. Although deceleration of head growth is a supportive feature, it is no longer necessary for diagnosis. Exclusion criteria include other primary causes of neurologic dysfunction and abnormal psychomotor development in the first 6 months of life.

• What lab findings (gene function or biochemical data) are associated with the disease?
• an MECP2 mutation, that resulted in decreased, but not absent MECP2 function.

• What type of inheritance governs this disease?

·       family recurrences of Rett syndrome comprise only approximately 1% of the total reported cases; the vast majority of cases are sporadic.

Independent Assortment Webquest

http://www.biology.arizona.edu/mendelian_genetics/problem_sets/dihybrid_cross/dihybrid_cross.html

Go through questions 1-9 of the tutorial. If you answer any question incorrectly, review the tutorial material and try again.

When you have completed this much of the tutorial, answer the questions below:

1. What type of gametes will be produced by a plant of genotype AaBb?

            a. The type of gametes that will be produced by a plant of genotype AaBb is AB,Ab,ab, and aB

2. What type of gametes will be produced by a plant of genotype aabb?

            a.the type of gametes that will be produced by a plant of genotype aabb would be ab.

3. List all the genotypes you would find among the offspring of an AaBb x aabb test cross.

            a.AB,ab,Aa,Bb,Ab,Ba

4. What is the expected phenotypic ratio of the offspring of an AaBb x aabb test cross?

            a.1/16

5. List all possible gametes from a trihybrid individual whose genotype is RrSsTt.

a.RS,ST,RT,rs,rt,st,St,Rs,Tr,Ts,Rt,Sr

Create-a-Baby Review

For the past two weeks in Biology we have been working on genetics. Today we were assigned to create a baby. We got a sheet of paper that has physical traits, for example: cheek dimples, eye shape, face shape...etc, and we had to partner up with a guy or a girl. If you were a girl you had to have a guy partner. If you were a guy you had to have a girl partner. Once we had partners we started to work on the worksheet handed out to us by the teacher. But since I was absent I ended up being partnered with another girl who was absent.


To the right is the worksheet we received to do this creative lab.



This worksheet we used shows the genotype and phenotype of the baby it also shows the genotype of the parents. Genotypes are the genetic makeup of an organism or group of organisms with reference to a single trait, set of traits, or an entire complex of traits, for example a girls gender is portrayed as xx and a guys gender is portrayed as xy or xyy, that is a genotype. The phenotype is the observable constitution of an organism. For example you see a girl and she, of course, looks female. An easier way to explain phenotype is the visible trait of a person. For example let's say you have freckles and you know you have freckles. A person sees your freckles and can tell that you have them. The genotype would either be Ff or FF. You would not know the genotype unless you get yourself tested. The big "F" represents the dominant trait, the trait that will have the higher probability of getting passed down to your kid/kids. The little "f" represents the recessive trait, the trait that has a lesser probability of being passed down.
Now let's take a look at the worksheet. The worksheet had many phenotypes for me and my partner work with. We had to either decide if we had the trait or not. For example my partner has small lips and I have big lips. Since my partner had small lips he had to write down "ll" and since I had big lips, I had to flip a coin to see what I needed to right down. I had two choices; one choice: "LL" or "Ll." I chose heads for "LL" and tails for "Ll." I flipped the coin and it landed on heads. I had to write down "LL." Once my partner and I got our genotypes we now had to figure out what our baby's geno and pheno type would be. Since I had the dominant "L," I pass one of those on. My partner has two little "l's"so he passes on a little "l." The baby ended up with "Ll" as the genotype.  The baby's phenotype is "big lips." We continued to do the same thing until we got to the hair color, skin color and eye color. Once we got to the hair color and that we had to do things a little differently. Every bodies skin, hair and eye color are made up of two genes instead of one. We started with hair color and since both our hair was brown we needed to flip a coin to see what genes we got. We had two choices, they are: "Rr SS" or "Rr Ss." Heads was "Rr SS," tails was "Rr Ss." I  flipped the coin first and it ended up "Rr SS." My partner flipped the coin and it ended up "Rr Ss." Now we had to flip for the baby. We flipped for each gene and the baby ended up with "Rr Ss," the baby had brown hair. We continued to do the same with skin and eyes. Once we finished all the geno and pheno types, we had to now draw the babies. I'll show you a picture of my baby I had to draw.

Since we were short one time me and my partner didn't name our baby this is her in her teen years.As for a name i'll call her Kira.

Once we finished the baby lab on the back of the worksheet we had to answer questions and find definitions. 

Below are the word we had to define and below them will be the questions we had to answer. 

Genetics Vocabulary:

Chromosome: Any of several thread-like bodies. 

Codominant: having both alles expressed equally in the phenotype of the organism.

Diploid: Having two similar complements of chromosomes.

Haploid: Pertaining to a single set of chromosomes.

Meiosis: Part of the process of gamete formation.

Recombination: The formation of new combinations  of genes, either naturally, by crossing over or independent assortment. 

Questions:

1) What was the probability  that you and your partner would produce a boy? A girl? 

         The probability of it being a boy was 50-50 because I was xx and my partner is xy. I think the probability will be the same for the girl as well. 

2) Explain how it is possible for your baby to have a visible trait that neither you nor your partner have.

          I could of had a dominant and recessive gene and he could have had two dominant genes, giving the baby the visible trait. 

3) If you and your partner repeated this exercise and produced another imaginary baby, do you think it would look just the same as the one you produced already? Explain.

         No the second child would look different because each kid has different genes than the other.

4) A women who is heterozygous for the chin dimple trait (Cc) marries a man without a chin dimple (cc). What are the possible genotypes (not visible) and phenotypes (visible) of their children. 

           The baby's genotype will be either cc or Cc, meaning they can have it or they won't have it.  

5) What is the probability that the man and women discussed in the preceding paragraph will have a baby with a chin dimple?

           There is about a 50-50 chance of their children receiving the chin dimple or not receiving the chin dimple because the mom is heterozygous.

6) A man and a women who are both heterozygous for two traits, the cheek dimple and the chin dimple traits, get married. What is the probability that they will have a baby that has cheek dimples, but not a chin dimple? 

          The probability of having a cheek dimple and not a chin dimple is about even since the parents are both heterozygous and neither one of them is homozygous. 

7) What is the probability that a man with dark blonde hair and a women with red hair will have a baby with brown hair?

          For the baby to have brown hair the chances are about 75-25 because the man has dark blonde hair and the mom had red. Using a punnet square helps figure this out more.  I used "Bb" to represent dark blonde. I used "Rr" to represent red. As you can the the child had a 75% probability of having brown hair. If you look at the top left corner, those are two dominant genes and below that one ( bottom left)  had only one dominant gene. Same with the one on the top right. The bottom right is two recessive genes meaning the baby or child is less likely to receive that set of genes. 

BR		Rb
	Br	rb

I hope you enjoyed our little lab on babies and genetics, I sure did!

Eugenics Essay

For Biology we had to do a research project about eugenics and write an essay below is the link to read my essay.

https://docs.google.com/document/d/1SRPJplT-UrIqVN9SWWAUAKWTgp07hYTTSYrNCyNLFVk/edit