6. Conclusion
Genotyping constitutional CNVs using low- and high-resolution SNP arrays has served as the primary screening method for identifying potential genetic markers associated with breast cancer risk. Despite the large amount of SNP array data available from breast cancer studies, the contribution of inherited copy number variation to breast cancer risk remains relatively understudied. A variety of algorithms have been generated and matched to these datasets for predicting copy number-affected regions throughout the genome. Applying such algorithms may reveal new common and rare variants that contribute to breast cancer risk. However, initial analyses suggest array-based CNV data may be unreliable without further validation using ancillary technologies, such as qPCR, Nanostring, and MLPA. Moreover, the current and future use of new higher resolution technologies, including next-generation sequencing, will be critical for characterising CNV breakpoints, to better interpret their potential impact on breast cancer risk.