Pedigrees

Nothing flashy, but a quick review of inheritance followed by a silent tutorial on how to use/read a pedigree. Remember a few vocabulary that we discussed:

Autosomal chromosome– this is referring to your body chromosomes
Sex chromosome – this is referring to your sex chromosomes (X & Y for humans)
Dominant – this is referring to an allele for a trait that can mask a recessive trait (typically shows in every generation)
Recessive – this is referring to an allele for a trait that is masked by a dominant trait (typically skips a generation)

Gregor Mendel & Punnett Squares

The following video clip reviews how to create and fill out Punnett squares. Now we like to use letters that represent what we are looking at and they should always be the same for dominant and recessive. When we write heterozygous allele pairs, they should always have the dominant allele written first.

If you want to go a little furthur and review some of the concepts from today (before we make it more complicated next class) watch the following lesson.

Genetics Practice Problems

The following websites have some practice problems covering all types of genetics.

http://www.cpo.com/tn/downloads/LSN_Skillsheet_11_2C.pdf
http://biology.clc.uc.edu/courses/bio105/geneprob.htm

The second half of the second page we have not covered all of and some of it we will not cover, so keep that in mind.

EXTRA CREDIT: Why Pedigrees & Family Trees Matter…

You know I do not provide many opportunities in the way of extra credit, but I thought this would be a good one. If you ever questioned the value of studying and learning about pedigrees, genetics, inheritance, etc. This webquest will help you to learn that family medical histories can inform you about your risk of developing a chronic disease. You will also discover that lifestyle modifications can help to reduce your risk. Below is a worksheet taken from Teach.Genetics at the University of Utah that will lead you on a WebQuest dealing with Using Family History to Improve Your Health. Complete this worksheet for extra credit.
http://teach.genetics.utah.edu/content/health/history/HealthFamilyWebQuest.pdf

If you would like to take this one step further and look at your own family health history, there is a link to materials for your own family health history search (includes both English & Spanish forms).
http://teach.genetics.utah.edu/content/health/history/What’s%20Your%20Story.pdf

Acute myeloid leukaemia genes’ role discovered

By James Gallagher
Health reporter, BBC News

Three groups of mutations which cause acute myeloid leukaemia, a cancer of the white blood cells, have been identified by scientists.

The researchers suggest their work on mice, published in Nature Genetics, could lead to new treatments.

Two thousand people in the UK are diagnosed with acute myeloid leukaemia each year.

The charity Leukaemia and Lymphoma Research said the study offered invaluable insight.

Immature
During the illness, the bone marrow, which produces blood cells, starts to churn out immature white blood cells.

This changes the balance of the blood.

The white blood cells are not properly developed so they cannot fight infection and there are too few red blood cells to carry oxygen around the body.

The disease can be fatal within weeks if left untreated.

The research group at the Wellcome Trust Sanger Institute investigated how this form of leukaemia arises because they say there had been little progress in developing new drugs.

Three groups
The most common mutation implicated in the cancer is to the Npm1 gene.

By switching this gene on in blood cells in mice, the researchers were able to show that it boosted the ability of cells to renew themselves, which is a sign of cancer. Yet only a third of mice went on to develop leukaemia.

The researchers concluded other mutations must also play a part.

They randomly mutated genes in mice, with a technique known as insertional mutagenesis. By looking at mice which developed cancer, they could then trace which mutations were involved.

They found two additional types of mutation. One affects cell division and growth, while the other modifies the cell’s environment.

Dr George Vassiliou, consultant haematologist from the Wellcome Trust Sanger Institute, said they had “found critical steps that take place when the cancer develops. Identifying the biological steps in turn means we can look for new drugs to reverse the process.”

He told the BBC: “Getting new drugs to patients could take decades, but what can happen sooner is using drugs which are already on the shelf, but in a more targeted way.”

Dr David Grant, scientific director at Leukaemia & Lymphoma Research, said: “New designer drugs which target specific genetic mutations are proving increasingly effective in the treatment of blood cancers.

“This is a very important study as it offers an invaluable insight into the role of the most common form of mutation found in acute myeloid leukaemia. It explains how it develops and the other genetic factors that drive the leukaemia’s growth.

“It offers a potential model for the development of new drugs for this terrible disease in the future.”