MadSci Network: Genetics
Query:

Re: Testing for mutated genes and DNA changes.

Date: Wed Mar 25 23:03:14 2009
Posted By: John J Peloquin, Fellow
Area of science: Genetics
ID: 1237950041.Ge
Message:

To reprise a definition, a mutation is a change in a gene- actually a change in the DNA sequence, though epistasis and imprinting can confuse the matter. Wikipedia has an extensive discussion of the matter at: http://en.wikipedia.org/wiki/Mutation

Anyway, I think you are asking about testing for genetic diseases. However,an analysis of the DNA sequence of a given gene can show that the DNA is "different" from "normal" alleles. Many mutations are "neutral" or have no visible effects. This can happen when the DNA change codes for the same amino acid in the protein, or if the amino acid chance doesn't change the behavior or activity of the protein.

Furthermore, a test for medical reasons must be validated and FDA approved. Tests involving amplification and sequencing of a DNA sequence believed to be involved in a disease state can tell you that there's a difference, but that difference may not change the activity of the protein. An example are some tests for mutations in the BRCA loci. Many of the mutations in this gene are not associated with disease whereas others are associated with an increase in chances of breast cancer.

Finally, there are DNA sequences that do not code for proteins but code for regulatory RNAs. This type of change is being heavily investigated and their meaning with regards to disease is not fully understood.


Current Queue | Current Queue for Genetics | Genetics archives

Try the links in the MadSci Library for more information on Genetics.



MadSci Home | Information | Search | Random Knowledge Generator | MadSci Archives | Mad Library | MAD Labs | MAD FAQs | Ask a ? | Join Us! | Help Support MadSci


MadSci Network, webadmin@madsci.org
© 1995-2006. All rights reserved.