Amorph

Genomics

See Also

• Genotype?
• Phenotype
• Mutation?
• [Single nucleotide polymorphisms (SNPs)]?
• Allele

Description

An amorphic mutation, or amorph, is a genetic mutation? resulting in either reduction or absence of the gene product at the molecular level, or absent function at a molecular level, also called a null allele.

Discussion

In the human [ABO Blood Group? ABO blood group] system, the alleles for the A-antigen? and B-antigen are co-dominant, thus they are both expressed if both are present, giving blood type AB. The allele for O blood type, however, is actually exactly the same as the allele for the A-antigen, but with just one different base pair of neucleotides, probably due to genetic mutation?. The protein coded for is non-functional and therefore the gene is expressed phenotypically as the lack of any blood group antigen. The allele for O blood type may therefore be considered as a null allele.

Links

Attribution

• This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Null allele.