Basic concepts of medical genetics,pathogenetics,Part 2

Point mutations refer to mutational events that involve one single base of the gene irrespective of the size of the gene. Lethal genetic diseases can be caused by single point mutations, even in very large genes. A well known example is Duchenne myopathy due to single point mutations of the dystrophin gene which is the largest human gene composed of 2.4 million bases. Sickle cell anemia is another example of a drastic genetic disease resulting from a single point mutation of the beta globin gene. Point mutations account for nearly 70% of currently defined human single gene disorders [1].