Are Multiple Allelism and Gene Polymorphism the same?

[Rongeet Banerjee]

Is Multiple Allelism and Gene Polymorphism same ?If not

then why?

 

[Andrew Mason]

If there is a material difference it is extremely subtle. Perhaps @Ygggdrasil may wish to comment. They are essentially the same thing as far as I can see. Polymorphisms such as RFLPs and VNTRs are polymorphisms at specific loci within genes resulting in a gene polymorphism ie. gene having different DNA sequences within a population without impairment of gene function. That is also the definition of a multiple allele. While multiple alleles could result from sequences that differ at different loci within the gene that would still result in a gene polymorphism.

 

[jim mcnamara]

In Thompson & Thompson Medical Genetics (2015):
multiple allelism is the state of having more than two alternative contrasting characters controlled by multiple alleles at a single genetic locus.

So, you can get somewhat different perspectives on definitions. i.e., 3 different alleles minimum. Each with different effects.

edit: fix grammar

 

[Rongeet Banerjee]

In Thompson & Thompson Medical Genetics (2015):
multiple allelism is the state of having more than two alternative contrasting characters controlled by multiple alleles at a single genetic locus.

So, you can get somewhat different perspectives on definitions. i.e., 3 different alleles minimum. Each with different effects.

edit: fix grammar

For Multiple Allelism, we have studied example of Blood Groups.
Can you give me an example for Gene polymorphism.

 

[jim mcnamara]

I think you missed the point. This is not an either/or thing, it is arbitrary, a human concocted definition, a way to cubbyhole things.

You asked if there were different definitions. There are. Think of multiple alleles as an extended form of polymorphism.
Example:
Consider Gregor Mendel's pea experiments. He classified what he saw as dominant and recessive.
In other words polymorphic. There is your example. It turns out that other varieties of peas have additional genes at the "wrinkled" locus. He could not have known that. So his experiments show 2 alleles.

 

[atyy]

For Multiple Allelism, we have studied example of Blood Groups.
Can you give me an example for Gene polymorphism.

I don't think there is any difference between an allele and a polymorphism. There's similar usage in Wikipedia https://en.wikipedia.org/wiki/Allele: "At the lowest possible size an allele can be a single nucleotide polymorphism (SNP)." and the reference they cite https://www.ncbi.nlm.nih.gov/pmc/articles/PMC102496/.

Here's a pretty clear example: "If a SNP occurs within a gene, then the gene is described as having more than one allele." https://www.nature.com/scitable/definition/snp-295/

 

[Andrew Mason]

It appears to me that the terms "allele" and "polymorphism" are used to refer to 1) different phenotypic expressions of a particular genetic trait (eg. colour), 2) different DNA sequences for a particular gene and 3) different DNA sequences at particular locii on chromosomes. It may be that as knowledge of genes and DNA and protein expression evolved, the meanings attached to these terms evolved as well.