How to Determine The Chances of Disease By ms. S. Brown

Warnings Is there a way to tell if someone is susceptible to disease? How? Is there a job specifically for this? http://lexfridman.com/blogs/thoughts/files/2012/12/Confused-Doctor.jpg

What is a Pedigree? Has anyone heard of pedigrees in terms of horses or dogs? Not just talking about dog food http://www.pedigree.com.au/imageGen.ashx?Compression=100&width=860&height=370&image=/media/1298/dogbreeds.png http://www.singingheartsfarm.com/news/ckeditor/filemanager/userfiles/Prince%20Momentus%20SF%2012-5-12_8934.jpg

Pedigree Pedigree is a chart of how traits are carried by a family Symbols: Boys: Girls: People who marry in are considered normal Colors mean they have the trait (not necessarily dominat/recessive) Potter Pedigree Harry is a wizard. His father, James, was a wizard and his mother, Lily, was a witch. Both of Harry’s dad’s parents had magical abilities; however, Harry’s mother’s parents did not nor does her sister, Harry’s Aunt, Petunia. Petunia is married to Vernon Dursley and they have a son, Dudley. None of the Dursleys have magical powers. Use shading to indicate genotype. Also, write the names and genotypes below each of the circles or squares. For those who only one allele is known, write the known allele and a question mark. Complete the pedigree on the back of this paper. CP Biology Usually pedigrees track disease What do you think of when you think disease? Disease has a negative connotation, but we can see that Magic is similar to a “disease” and it is just part of a factor of a person rather than the whole person. How can science terminology be used? In the case of pedigree, we are looking at how genes are passed from one biological parent to child according to X and Y chromosomes. These pedigrees are for specific contexts, as tracking disease. Thus, we look at the biological identity of a person; however, a person may not identify as their biological identity. Science terminology can be used to be objective and is looking at specific factors. Science terms are not supposed to be used to discriminate others. However, this has not always been the case. How has this not been the case? Why? This is due to who is in power in the science world. These pedigrees are for specific contexts, as tracking disease.

How to Draw a Pedigree My Family: Your Turn! 3 generations Just learning how to trace a family (no trait yet)

Pedigree Now pick a trait and color it in through the pedigree Eye Color in my Family: Who do you think gave you this trait? Is there a pattern? Show eye color for my family (brown versus blue) -> talk about how there is a pattern (autosomal dominant) but it can be spontaneous Autosomal dominant lead into Huntington Disease

Huntington’s Disease Neurodegenerative genetic disorder What does that mean? Affects muscle coordination and leads to mental decline Symptoms appear between ages of 30-50 years and worsen over a 10-25 year period Result of an addition mutation (CAG) Approximately 30,000 symptomatic Americans Fatal http://hdsa.org/what-is-hd/

Scenario 1: Huntington’s Disease This is a family with Huntington’s Disease What patterns do you notice? Does it skip generations? What is the ratio of affected children to not affected children in part II. I. 1 2 II. III.

Scenario 1: Huntington’s Disease Nevaeh and Jordan just got married and decided to have a baby together. However, Huntington’s Disease runs in both of their families. Jordan has Huntington’s Disease and is heterozygous. Nevaeh does not have Huntington’s disease and is homozygous. Draw the Punnett Square for original parents What is the likelihood their child will have Huntington’s Disease? Is Huntington’s Disease a dominant or recessive trait? What pattern would you see on the pedigree? What is dangerous about this inheritance pattern?

Scenario 1: Huntington’s Disease What is the genotype of parents? What is the genotypes of those with Huntington’s Disease? without Huntington’s Disease? I. 1 2 II. III.

Autosomal Dominant-Tricks of the Trait It does not skip generations There are no carriers Males and females have equal chance of being affected. There is about a ½ chance a baby will get the trait if one of their parents have this trait Normal siblings will not pass on the trait

Sickle Cell Disease Crescent blood cells Origin: Africa Malaria Resistance Affects about 90,000 to 100,000 Americans 1 in 500 Blacks or African-American Births 1 in 12 Blacks or African-Americans Show another side of sickle cell after talking about how it was a point mutation in earlier classes

Scenario 2: Sickle Cell Anemia This is a family with Sickle Cell Anemia What patterns do you notice? How is it different than Huntington’s Diseae I. II. III. IV.

Scenario 2: Sickle Cell Anemia MarÍa and Mateo are planning on having a child. They are each carriers for Sickle cell trait. What is a carrier? Carrier: anybody carrying the trait but not expressing it What are the chances their child will have sickle cell? Draw a Punnett Square How many children will have sickle cell out of 4?

Scenario 2: Sickle Cell Anemia What are the genotypes of parents In number III? What are these parents called? What is the genotype of the affected What are the possible genotypes of The unaffected children? I. II. III. IV.

Autosomal Recessive-Tricks of the Trait Skips Generation Males and Females are equally likely to be affected On average, the recurrence risk to the unborn sibling of an affected individual is ¼ If only one parent is a carrier, children will not be affected Usually no family history Look at III 2-3 versus 7

End of Day 1

Sex-Linked Traits What did we learn from this segment