Human Chromosome Webquest blog

These questions have been taken from a webquest I've been doing in Biology. I researched Narcolepsy and I think it's pretty interesting. I also looked at insomnia, but that isn't very important but it was neat to finally know what went on with it. Watch the Prezi!!!

Insomnia on Prezi

 *What disease did you choose and what gene is/genes are associated with this disease? I chose Narcolepsy to research. The prepro-orexin gene is associated with Narcolepsy.

*On what chromosome are these genes/is this gene located? The prepro-orexin gene is located on the chromosome 17q21-22.

·      When was the disease first reported in the scientific literature? In the 1990’s.

·      What are some of the clinical symptoms of this disease? Daytime drowsiness, cataplexy (sudden weakness of muscles), and occurrences of REM during wakefulness are the clinical symptoms of Narcolepsy.

·      What lab findings (gene function or biochemical data) are associated with the disease? Narcolepsy appears at random instead of being inherited. It was thought that the cause of narcolepsy was because the body’s immune cells were attacking neurons that secrete hypocretin.

·      What type of inheritance governs this disease? There is no specific inheritance that deals with this disease. Instead it is appears randomly.

In Sickness and Health!

In Biology we've been working on the sickness and health activity where we work at being genetic counselors. The following questions are each of the stages that i passed to finish the activity. Check out the website here.

Questions

1. Do autosomal dominant disorders skip generations? No because they need to have a female carrier. 
2. Could Greg or his mother be carriers of the gene that causes myotonic dystrophy? His mother could be a carrier but Greg could not because he is male.
3. Is there a possibility that Greg’s aunt or uncle is homozygous for the myotonic dystrophy (MD) gene? Yes.
4. 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? There is a 50/50 chance that Greg's cousin inherited MD. 
5. What is the possibility that Greg and Olga’s children could inherit the MD gene? There isn't a chance because Greg can not be a carrier without having symptoms of the disease. 

Questions

1. What are the hallmarks of an autosomal recessive trait? There are five hallmarks of autosomal recessive inheritance:
   1. Males and females are equally likely to be affected.
      
   2. On average, the recurrence risk to the unborn sibling of an affected individual is 1/4.
      
   3. The trait is characteristically found in siblings, not parents of affected or the offspring of affected.
      
   4. Parents of affected children may be related. The rarer the trait in the general population, the more likely a consanguineous mating is involved.
      
   5. The trait may appear as an isolated (sporadic) event in small sibships
2. What does consanguineous mean? Why is this concept especially important when discussing recessive genetic disorders? It means people coming from the same ancestor, this is important because if two people are related then it is more likely they will receive the disease.
3. 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 seems to stay mostly in boys, making women carriers. 

Questions

1. What are the characteristics of X-linked recessive inheritance? The characteristics are that they are only passed on to boys and the disease does not affect women.
2. Why does a son never inherit his father’s defective X chromosome? The mother has to pass on the gene to her son.
3. What is required for a woman to display a sex-linked recessive trait? She would have had to inherit it from her mother.
4. Return to the pedigree drawn earlier for Greg and Olga; mark those persons who are carriers of the factor VIII deficiency gene. Link to Picture
5. 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? There is a 50% chance that she will pass the VII deficiency to her children.
6. 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? There is a 25% chance that he will the gene onto his children. He wouldn't be able to pass the genes onto his children.

Questions

1. What is the second equation? 1 of 3,000
2. The incidence of cystic fibrosis in Hispanic Americans is 1/4500 while in African Americans cystic fibrosis is seen in 1 of every 15,000 births. What is the carrier frequency for each of these populations? 1 in every 3 women.
3. What is the probability of two Hispanic Americans having a child with cystic fibrosis, given that there is no history of the disease in either’s family? Zero percent.
4. Carol is an African American woman who does not suffer from CF. Both of her parents are healthy but her brother has cystic fibrosis. Carol is planning a family with her husband Marcus, who is also African American but who has no history of CF in his family. What is the probability of their having a child with CF? 50%

Questions

1. What are some of the risks and benefits of genetic testing as it relates to legal (not medical) issues? Risks of genetic testing are that the child could miss out on job opportunities or be prejudiced. Benefits are that they can catch the disease early on and help. 
2. Do you think an unintended consequence of genetic testing could be that people would be less liable to seek medical care out of fear that they could later be denied life or health insurance? What laws should be used to govern the use of genetic data of this type? Yes, that is a viable consequence. A law should be made to provide everyone with equal insurance rights. 

Eugenics!

The definition of eugenics is the following. (Taken from dictionary.com.)

–noun ( used with a singular verb )
the study of or belief in the possibility of improving the qualities of the human species or a human population, especially by such means as discouraging reproduction by persons having genetic defects or presumed to have inheritable undesirable traits(negative eugenics)  or encouraging reproduction by persons presumed to have inheritable desirable traits (positive eugenics).

For the past week or so we’ve been working on eugenics. It’s interesting to think that people used to be sterilized (neutered) because of a defect that had a possibility of being passed on in a mother or father’s chromosome. I think this is a little bit unnecessary because sometimes certain genes aren’t passed on. There is always a chance that the child won’t receive a gene for brown eyes if the mother’s eyes are dominantly blue and the father’s eyes are brown with a recessive gene for blue eyes.

A little history on eugenics now, yes? Eugenics originates in America after the Civil War. During reconstruction many immigrants were moving in. There was a decline of births in elite families and an incline in poor families. Social Darwinism was on the incline also. It basically says “survival of the fittest” and it was taken from there that the elite were the fittest. It was decided that because much money was spent on the “degenerate” poor, sterilization would be the best option for the survival and betterment of our race. They based a lot of their work on IQ tests and behavior, such as criminal activity, prostitution, and social standing. Richard Dugdale did research on a family of 700 of these degenerates. He thought that the degeneration may have been based on poor environment, but when the degenerate family was mixed with an elite family, the “degenerate” genes were passed on. From there, increased marriage restrictions occurred, and the 8th of the 18 suggestions of dealing with these types of genes was euthanasia. People were sterilized unfairly, people like Carrie Buck, who was put in a home for the “feeble-minded” with her mother, both were accused of being promiscuous and imbeciles. Carrie’s seven month daughter was also labeled feeble-minded, although later grades showed the opposite. Hitler’s eugenics seem much crueler, as he sterilized thousands of Jews and Gypsies, preferring a blond and blue eyed race. But the United States also preformed involuntary sterilizations on criminals in prisons. I can’t determine which could be worse, as they’re both involuntary. But I believe Hitler took his too far. Way too far.

I really don’t agree with eugenics, like Punnett said at the first meeting of international eugenics in 1911, “Except in very few cases, our knowledge of heredity in man at present is far to slight and far too uncertain to base legislation upon.”

They really didn’t know enough about a person’s genetic structure to be allowed to kill or neuter said person. I don’t believe that in any way should it be justified by a few defects that may not even be passed on. A few days ago, I tested my mother and sister with the little strips Mr. Ludwig handed out. They could (much to my glee) taste them. My mom said that it was a decent taste, but I think that may have been the result of her previous gum chewing. I didn’t warn my sister about what I was giving her and got a wonderful reaction from her. I had the same reaction. What does it mean? Would it have meant back in the day that we needed to be sterilized? (Just so you know what I’m talking about, it means “neutered”.) People were sterilized for the silliest reasons. At one point, it was believed that you could have a predisposition to be a criminal if you father was due to a gene that could be passed on. I heard once that you have a predisposition to like broccoli. I guess that makes sense seeing as how half the population hates vegetables. What if we sterilized people who didn’t like broccoli? I suppose it would cut down on the amount of picky children but what if all those people had  gene that made the body more susceptible to cancer cures? What if they could stop radiation? Then it’d be horrible to make sure they didn’t have any children.


Take a look at the eugenics archive to see what I'm talking about :).