Analysis of CHEK2 FHA domain in Czech patients with sporadic breast cancer revealed distinct rare genetic alterations

Abstract

The CHEK2 gene mutations I157T (c.470T>C) and IVS2+1G>A affecting the forkhead-associated domain (FHA) have been shown to increase the risk of breast cancer development in several populations. We analyzed the CHEK2 gene segment coding for FHA domain in 673 unselected breast cancer patients and 683 controls from the Czech Republic using the denaturant high-performance liquid chromatography. The found frequency of predominant FHA alteration I157T did not differ between breast cancer patients (19/673; 2.82%) and controls (17/683; 2.49%; P=0.71). Besides this mutation we characterized another nine alterations-six located within FHA coding sequence and three occurring in introns 1 or 2). Eight variants occurred once each in patients with breast cancer and two were present in controls. Three alterations found in breast cancer patients were novel missense variants (Y159H, T172A, and L174F) affecting highly conservative residues in FHA domain. Despite the lack of association of I157T mutation with breast cancer development in our population we deduced that the FHA domain is the subject of rare population-specific alterations that might modify risk of various cancers.

Alterations of CHEK2 forkhead-associated domain increase the risk of Hodgkin lymphoma

“…We ascertained six different CHEK2 alterations localized within FHA-coding region (c.470T>C, c.475T>C, c.542G>A) or in its proximity (IVS1-5T>A, IVS2+24C>T, IVS2-54C>T (this variant was erroneously referred to as IVS2-55C>T in our previous publications [14,17]; Table 2). The overall fre- quency of CHEK2 alterations in the group of HL patients (5.7%) differed significantly from that characterized previously [13] in controls (2.8%; p = 0.04). Presence of any alteration within analyzed region was associated with increased risk of HL development (OR = 2.11; 95% CI = 1.08 -4.13).…”

“…Except for the c.542G>A (p.R181H) mutation, all other identified alterations were previously found in Czech breast, colorectal or pancreatic cancer patients [13,14,17]. The R181H was identified in breast and prostate cancer patients from Germany [18] and the USA [19], respectively, however, this variant most likely do not interfere with the function of the CHK2 (Align GVGD: Class C0) and together with c.538C>T (p.R180C -identified in one control subject) may represent neutral CHEK2 sequence variants.…”

“…Clinical characteristics of patients are summarized in Table 1. Control group of 683 non-cancer individuals was described in detail previously including the results of CHEK2 mutation analysis [13,14]. All lymphoma patients and controls were of Caucasian origin from the same geographical area of the Czech Republic.…”

“…Genomic DNA was isolated from whole peripheral blood using QIAamp DNA Blood Mini Kit (Qiagen) or using automated DNA preparation system (MagNA Pure LC 2.0, Roche) according to the manufacturer's instructions. Mutation analysis of FHA-coding region was performed as described previously [13]. Briefly, FHA-coding region of CHEK2 gene (covering exon 2 and 3) was PCR-amplified in a single fragment and analyzed by denaturing high-performance liquid chromatography (DHPLC, WAVE system, Transgenomic).…”

Lack of CHEK2 Gene Mutations in Differentiated Thyroid Carcinoma Patients using High Resolution Melting Analysis

“…In Ile157Thr (470T>C) mutation of CHEK2 gene, it was observed that 157Thr was located in the second fork head-associated domain (FHA) of the protein and the mutation resulted into the reduction of the activity of this protein in response to DNA damage (Ahn et al, 2002). IVS2+1G"A mutation revealed abnormal splicing and it led into frame shift and synthesis of truncated protein (Kleibl et al, 2008).…”