Novel Nonsense Variants c.58C>T (p.Q20X) and c.256G>T (p.E85X) in the CHEK2 Gene Identified in Breast Cancer Patients from Balochistan

Breast cancer is very common and the leading cause of cancer deaths among women globally. Hereditary cases account for 5-10% of the total burden and CHEK2, which plays crucial role in response to DNA damage to promote cell cycle arrest and repair or induce apoptosis, is considered as a moderate penetrance breast cancer risk gene. Our objective in the current study was to analyze mutations in related to breast cancer. A total of 271 individuals including breast cancer patients and normal subjects were enrolled and all 14 exons of CHEK2 were amplified and sequenced. The majority of the patients (>95%) were affected with invasive ductal carcinoma (IDC), 52.1% were diagnosed with grade III tumors and 56.2% and 27.5% with advanced stages III and IV. Two novel nonsense variants i.e. c.58C>T (P.Q20X) and c.256G>T (p.E85X) at exon 1 and 2 in two breast cancer patients were identified, both novel and not reported elsewhere.