Question

Check all of the statements that apply to neomorphic alleles of genes Check All That Apply They are usually dominant to normal alleles. They are usually recessive to normal alleles. They can generate normal proteins. They can generate mutant proteins The HD-allele that makes a mutant protein with too large a polyQ region and thus causes Huntington disease is a good example. The mutation can be in either the promoter/enhancer or in the coding region

Answer 1

A neomorphic mutation results in a novel gene activity. This means that mutation causes generation of an altered gene product owning a novel molecular function or a differential gene expression pattern. These alleles differ from antimorphic and hypermorphic forms as they are not sensitive to dosage. This means changing the wild type dosage of gene does not have any effect on the phenotype of the neomorph.

These mutations are usually having dominant or semidominant gain of function for the novel mutation.

Based on this understanding, let us identify the correct choices.

1) They are usually dominant to normal alleles.

2) They can generate mutant proteins

3) The HD-allele that makes a mutant protein with too large a polyQ region and thus causes Huntington’s disease is a good example.

4) The mutation can be in either promoter/enhancer or coding region

5) They can be missense mutations

6) They can be frameshift mutations

7) A nonsense suppressor mutation is a good example

8) They can have mutations in splice donor or acceptor sites

They cannot have a non-sense mutation as it will cause premature chain termination by introduction of a stop codon.

They cannot be amorphic as amorphic mutation causes complete loss of protein function by disrupting translation.