Missense mutation

A missense mutation occurs when there is a base subsitution for example, A being changed to C, which will then causes an amino acid alteration. If this mutation were to happen in the codon CAT, it would change to CCT and so the amino acid produced would be altered from His to Pro. Due to this alteration in amino acid sequence there will be a knock-on effect on the finalprotein structure and therefore its function^[1].

An example of a missense mutation in genetic disease in the mutation of a proline to a histidine at residue 23 of the gene encoding the visual pigment rhodopsin^[2]. This study has concluded that this missense mutation is one of the many possible causes of the rare disease retinitis pigmentosa, which affects night vision.

Reference

1. ↑ Daniel L. Hartl, Maryellen Ruvolo,(2012),Genetics Analysis of Genes and Genomes, 8th edition, United States of America: Jones and Bartlett Learning LLC, an Ascend Learning Company. Chapter 14, Page 524,525.
2. ↑ Dryja TP, McGee TL, Reichel E, Hahn LB, Cowley GS, Yandell DW, Sandberg MA, Berson EL. A point mutation of the rhodopsin gene in one form of retinitis pigmentosa. Nature. 1990;3:364-366