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can any one pls explain me what is difference between 1) compound heterozygous mutation...
2) heterozygous mutation....
& 3) homozygous mutation....

i know about the heterozygous mutation....& homozygous mutation....but wt is "compound heterozygous mutation"...??:confused:
 

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I think it just means that there are different mutations in both recessive alleles in an autosomal recessive disease.

For example - In Tay Sachs dz - The HEXA gene that codes for Hexoseaminidase A can have either the same mutation in both alleles causing the form we know - infantile onset. Or, if there are different, compound heterozygous mutations in the two alleles this may improve the patient's prognosis and you might not see symptoms until later on in life.

Compound heterozygosity is associated with variable penetrance. The two different recessive mutations on the two recessive alleles can either worsen or improve the patient's prognosis - for example - as stated above, in Tay Sachs it can improve prognosis but in Hemochromatosis it can make the patient more sick sooner if they have the compound heterozygous mutation.

Hemochromatosis HFE gene article:
http://www.scripps.edu/bcmd/pdfarea/issue_13_97/martinez.pdf

Wiki article:
http://en.wikipedia.org/wiki/Compound_heterozygosity
 
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