The team embarked on a two-step genetic expedition. First 61 Finnish, Swedish and Icelandic breast cancer patients who fit the criteria were recruited and DNA from tumor tissue was compared with control material in so-called comparative genomic hybridization, which reveals deletions in the DNA sequence. Next, this finding was supported by genetic studies. This complex statistical method can determine the likelihood that a gene is inherited and point to the gene's location. But she emphasizes the results are still preliminary.
Many questions still remain.
The spotlighted region on chromosome 13 spans 5 million base pairs, which could represent up to 150 genes. Though not yet in sight, researchers agree that the first possible clinical application of a new breast cancer susceptibility gene would be a diagnostic test. A very small minority opts for the preventive mastectomy. . . . . . . . . . . . . . . . Kainu, T. et al . Somatic deletions in hereditary breast cancers implicate 13q21 as a putative novel breast cancer susceptibility locus.