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Cell divison and cancer

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Gene mutations and cancer

The information in DNA is carried in the sequence of bases. Changes, or mutationmutation
A change in the arrangement or amount of genetic material in a cell.
s, in just one or two bases can scramble the information and mean that the gene does not work properly. If this mutation is in a gene that controls cell divisioncell division
The process by which a parent cell divides into two daughter cells.
it can trigger the uncontrolled replication of that cell. This faulty gene is copied to all the new cells and so the uncontrolled growth continues. The cells form a tumour.

The information in DNA is carried in the sequence of bases. Changes, or mutationmutation
A change in the arrangement or amount of genetic material in a cell.
s, in just one or two bases can scramble the information and mean that the gene does not work properly. If this mutation is in a gene that controls cell divisioncell division
The process by which a parent cell divides into two daughter cells.
it can trigger the uncontrolled replication of that cell. This faulty gene is copied to all the new cells and so the uncontrolled growth continues. The cells form a tumour.

Genes and DNA

To find out more about DNA, genes and mutationmutation
A change in the arrangement or amount of genetic material in a cell.
s click on the links:

Genes and DNA

Gene mutations

Researchers are starting to understand the genetic basis of many cancers. This allows improvements in diagnosis, medicines and treatments. It is even becoming possible to see which people may be more likely to develop certain types of cancers.

Dna1mut

Cancers linked to known genetic markers

Cancer is quite rare, especially in people under the age of 60. However, some cancers appear to 'run in families'. Researchers have found that certain mutated genesmutated genes
Genes where the sequence of DNA has changed.
, passed from parents to their children, can dramatically increase the chance of developing a particular cancer. Inheriting the faulty gene does not guarantee that the person will develop cancer but it appears to increase the chance that they will.

Genetic tests can be made to see if a person has inherited a mutated gene that makes them more likely to develop cancer. Some genes, such as P53, are associated with a range of types of cancer, others are specific to just one type.

Cancer Examples of genes associated with specific cancers:
Breast cancer BRCA1, BRCA2
Ovarian cancer BRCA1, BRCA2
Prostate cancer BRCA2, HPC1, HPC2, HPCX
Melanomamelanoma
A tumour which arises from pigment-containing cells, especially in the skin.
(skin cancer)
CDKN2A, MITF
Stomach CDH1 (E-cadherin)
Bowel cancer MSH2, MSH6, MLH1, APC

Using the information

There are ethical issues around genetic screening. The results can tell a person if they are at a higher than normal risk of developing cancer, but what should be done with this information?

Would you want to know that you were at high risk? What would you do if you did know? How would you react if you were clear of any mutated genesmutated genes
Genes where the sequence of DNA has changed.
? How should doctors handle this information? Should doctors screen for cancers that cannot be cured?

What decisions would you make? How would you help someone thinking about having a genetic test decide what to do?

For more on the ethical questions relating to inherited disorders, see the Human Genomehuman genome
The complete sequence of all 20,000-25,000 human genes. That is, which chromosomes they are in and whereabouts the gene appears on that chromosome's piece of DNA.
Project
 resource.