Fanconi anemia gene mutations are not involved in sporadic Wilms tumor

Recurrent PALB2 mutations and the risk of cancers of bladder or kidney in Polish population

Introduction

The role of PALB2 in carcinogenesis remains to be clarified. Our main goal was to determine the prevalence of PALB2 (509_510delGA and 172_175delTTGT) mutations in bladder and kidney cancer patients from Polish population.

Materials and methods

1413 patients with bladder and 810 cases with kidney cancer and 4702 controls were genotyped for two PALB2 variants: 509_510delGA and 172_175delTTGT.

Results

Two mutations of PALB2 gene were detected in 5 of 1413 (0.35%) unselected bladder cases and in 10 of 4702 controls (odds ratio [OR], 1.7; 95% CI 0.56–4.88; p = 0.52). Among 810 unselected kidney cancer cases two PALB2 mutations were reported in two patients (0,24%) (odds ratio [OR], (OR = 1.2; 95% CI 0.25–5.13; p = 0.84). In cases with mutations in PALB2 gene cancer family history was negative.

Conclusion

We found no difference in the prevalence of recurrent PALB2 mutations between cases and healthy controls. The mutations in PALB2 gene seem not to play a major role in bladder and kidney cancer development in Polish patients.

Genetic and epigenetic analyses guided by high resolution whole-genome SNP array reveals a possible role of CHEK2 in Wilms tumour susceptibility

Wilms tumour (WT), the most frequent malignant childhood renal tumour, shows a high degree of genetic and epigenetic heterogeneity. Loss of imprinting on chromosome 11p15 is found in a large fraction of cases and mutations in a few genes, including WT1, CTNNB1, WTX, TP53 and, more recently, SIX1, SIX2 and micro RNA processing genes (miRNAPGs), have been observed. However, these alterations are not sufficient to describe the entire spectrum of genetic defects underlying WT development. We inspected data obtained from a previously performed genome-wide single nucleotide polymorphism (SNP) array analysis on 96 WT samples. By selecting focal regions commonly involved in chromosomal anomalies, we identified genes with a possible role in WT development, based on the prior knowledge of their biological relevance, including MYCN, DIS3L2, MIR562, HACE1, GLI3, CDKN2A and CDKN2B, PALB2, and CHEK2. The MYCN hotspot mutation c.131C>T was detected in seven cases (7.3%). Full sequencing of the remaining genes disclosed 16 rare missense variants and a splicing mutation. Most of these were present at the germline level. Promoter analysis of HACE1, CDKN2A and CDKN2B disclosed partial methylation affecting HACE1 in a consistent fraction of cases (85%). Interestingly, of the four missense variants identified in CHEK2, three were predicted to be deleterious by in silico analyses, while an additional variant was observed to alter mRNA splicing, generating a functionally defective protein. Our study adds additional information on putative WT genes, and adds evidences involving CHEK2 in WT susceptibility.

Novel BRCA1 and BRCA2 pathogenic mutations in Slovene hereditary breast and ovarian cancer families

The estimated proportion of hereditary breast and ovarian cancers among all breast and ovarian cancer cases is 5–10%. According to the literature, inherited mutations in the BRCA1 and BRCA2 tumour-suppressor genes, account for the majority of hereditary breast and ovarian cancer cases. The aim of this report is to present novel mutations that have not yet been described in the literature and pathogenic BRCA1 and BRCA2 mutations which have been detected in HBOC families for the first time in the last three years. In the period between January 2009 and December 2011, 559 individuals from 379 families affected with breast and/or ovarian cancer were screened for mutations in the BRCA1 and BRCA2 genes. Three novel mutations were detected: one in BRCA1 - c.1193C>A (p.Ser398^*) and two in BRCA2 - c.5101C>T (p.Gln1701*) and c.5433_5436delGGAA (p.Glu1811Aspfs^*3). These novel mutations are located in the exons 11 of BRCA1 or BRCA2 and encode truncated proteins. Two of them are nonsense while one is a frameshift mutation. Also, 11 previously known pathogenic mutations were detected for the first time in the HBOC families studied here (three in BRCA1 and eight in BRCA2). All, except one cause premature formation of stop codons leading to truncation of the respective BRCA1 or BRCA2 proteins.