Can Genetic Variants Control Cancer Susceptibility?
As recently as a decade ago, many people believed that the cause and cure for all diseases would be discovered upon the sequencing of the entire human genome. But, like most experiments conducted in the laboratory, this information has led to more questions than answers. DNA is approximately 99.9% identical from one individual to the next. It is this 0.1% difference that confers a unique phenotype to each individual. In addition to being responsible for phenotypic variation, this “minor” variation among individuals can also promote susceptibility to diseases. Now, many scientists are beginning to associate disease risk with the inheritance of specific variants, or single nucleotide polymorphisms (SNPs). A SNP is a site where a single base substitution occurs at a frequency of at least 1% in the population. Approximately one out of every 1,900 base pairs in the human genome is a SNP, the most common type of variant identified by the Human Genome Project. Identifying these variants, or S
