Multiple Patterns of FHIT Gene Homozygous Deletion in Egyptian Breast Cancer Patients

Fragile histidine triad (FHIT) gene encodes a putative tumour suppressor protein. Loss of Fhit protein in cancer is attributed to different genetic alterations that affect the FHIT gene structure. In this study, we investigated the pattern of homozygous deletion that target the FHIT gene exons 3 to 9 genomic structure in Egyptian breast cancer patients. We have found that 65% (40 out of 62) of the cases exhibited homozygous deletion in at least one FHIT exon. The incidence of homozygous deletion was not associated with patients' clinicopathological parameters including patients' age, tumour grade, tumour type, and lymph node involvement. Using correlation analysis, we have observed a strong correlation between homozygous deletions of exon 3 and exon 4 (P < 0.0001). Deletions in exon 5 were positively correlated with deletions in exon 7 (P < 0.0001), Exon 8 (P < 0.027), and exon 9 (P = 0.04). Additionally, a strong correlation was observed between exons 8 and exon 9 (P < 0.0001).We conclude that FHIT gene exons are homozygously deleted at high frequency in Egyptian women population diagnosed with breast cancer. Three different patterns of homozygous deletion were observed in this population indicating different mechanisms of targeting FHIT gene genomic structure.