Identifying long-range control elements of the

BRCA1 is a tumour suppressor protein involved in many important pathways such as DNA repair, cell cycle regulation, apoptosis, spindle formation and telomere regulation. BRCA1 germline mutations confer the highest risk to breast cancer. Furthermore, reduced levels of BRCA1 are also observed in many sporadic breast cancers. Despite the obvious importance of BRCA1, genetic screening is usually restricted to BRCA1 exons and intron-exon boundaries. The possibility that mutations exist outside these regions has not been fully investigated and may be responsible for breast cancer predisposition in a subset of cases. It is becoming increasingly clear that long-range transcriptional control is an important mechanism for regulating gene expression. In support of this concept several human diseases, including breast cancer, have been associated with dysregulation in long-range control elements. Currently, only two papers have studied long-range regulation of BRCA1. In 2005, Wardrop et al identified a putative enhancer and silencer element within BRCA1 intron 2, 5kb downstream of the BRCA1 promoter [1]. Then in 2008, Tan-Wong et al identified distal regulatory elements located within the BRCA