Chromosome 2q24.2 is lost in sporadic but not in BRCA1-associated ovarian carcinomas

Aims: Comparison between BRCA1-associated and sporadic ovarian carcinomas is a potential method to identify candidate modifier gene/s involved in the carcinogenic pathway of either or both groups. A previous study identified a significant difference in the frequency of copy number gain at 2q24-q32 by comparing BRCA1-associated and sporadic ovarian tumour specimens using comparative genomic hybridisation (CGH). The present study aimed to investigate the reported allelic imbalance at 2q24-32 by amplification of several microsatellite markers at the region by quantitative microsatellite analysis (QuMA) using Taqman at the same region identified as a site of allelic imbalance. Methods: The copy number of the genomic region in 2q24 - 32 was established in 21 BRCA1-associated ovarian carcinomas and 14 sporadic cases using quantitative microsatellite polymerase chain reaction (PCR). Statistical analysis was performed using permutation test analysis. Results: A significant loss at D2S156 marker (2q24.2) (p=0.026) compared with the other three markers at 2q24 32 was found in the sporadic cohort but not in the BRCA1-associated group (p=0.385). Conclusions: Our data do not support the association between copy number gain at 2q24 - 32 and BRCA1 mutation status in ovarian cancers reported previously. The novel finding of the present study was significant loss at 2q24.2 in sporadic ovarian cancers.