Genetic mutations are permanent changes in DNA. They can be acquired during an individual's lifetime or inherited from a parent. Silent, nonsense, and missense are just some of the different types of mutations. When genetic errors are classified by their behaviours they are called morphs.
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There are a number of ways of classifying the different types of genetic mutations, such as the effect on fitness, and the effect on the DNA sequence - i.e. a point mutation is a single base substitution.
The classification of mutations based on their behaviour was created by Hermann J Muller (1890-1967). His classification scheme for genetic mutations consists of the following terms; amorph, antimorph, hypermorph, hypomorph, and neomorph.
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This is the most common type of mutation and it causes a loss of function of the protein product. It is also known as a 'null mutation.' Genetic mutations in an amorph allele (an alternative form of a gene at a specific locus) can cause any of the following;
Changes to the DNA base pair sequence of an antimorphic allele does result in a gene being present, but its protein product works against the normal gene's protein product. Antimorph mutations are generally dominant, and they are also known as 'dominant-negative' mutations.
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Hypomorph is a common type of genetic mutation and results in the loss of function of a gene product function. It is also sometimes referred to as a 'leaky' mutation.
The DNA sequence changes in a hypomorph allele can cause;