Bet you haven’t seen one of these in a while (that’s probably mostly because I’m super behind in this class.) A web quest! In this one, we researched a certain type of genetic disease and used the website below to research it. This site gets really in-depth so we had to only scratch the surface.
“THE HUMAN GENOME AND GENETIC DISEASE
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 the National Center for Biotechnology Information
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? 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!
-The three main parts of a chromosome, as viewed under a microscope, are the centrosome, short arm (p) and long arm (q). These can be used to identify locations on the chromosomes.
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.
-Menkes Syndrome
-Alport Syndrome
-Hemophilia A
-Immunodeficiency with hyper IgM
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/
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, it’s 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 does it do?).
Part 2.
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 or genes are associated with this disease?
-I chose breast and ovarian cancer because my great grandmother has conquered this disease twice in her life time. The two genes associated with these cancers are BRCA1 and BRCA2.
*On what chromosome is this gene(s) located?
BRCA1 is located on chromosome 17 while BRCA2 is located on chromosome 13.
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 (earliest citation)?
- In scientific literature, the first ever disease reported of breast cancer was in 1757 from a 19-year old diagnosed in her right breast.
- What are some of the clinical symptoms of this disease?
- Some clinical symptoms of breast cancer are soft tissue sarcomas, Li-Fraumeni syndrome, Cowden syndrome, and Peutz-Jeghers syndrome.
- What lab findings (gene function or biochemical data) are associated with the disease?
- Most commonly, mutations of the androgen receptor gene on the X chromosome and mutations in the RAD51 gene have been associated with breast cancer.
- What type of inheritance governs this disease?
- Based on scientific literature reports, families have a particular tendency for early-onset and bilateral breast cancer.
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