The origins and implications of Aluternative splicing

Ten percent of the human genome is composed of highly repetitive DNA sequences called Alu elements. It has recently been found that at least 5% of all human alternative exons are derived from Alu elements. Moreover, single nucleotide mutations can convert either alternative or otherwise silent Alu elements into constitutive exons and this can lead to the development of human disease. These results provide new insights into the function and dangers of 'junk DNA' in the human genome.