However, chromosomal instability syndromes such as Bloom syndrome, ataxia telangiectasia and Fanconi anaemia are inherited [6] and are considered to be genetic diseases. These disorders are associated with tumor genesis, but often have a phenotype on the individuals as well. The genes that control chromosome instability are known as chromosome instability genes and they control pathways such as mitosis, DNA replication, repair and modification.[7] They also control transcription, and process nuclear transport.[7]