Prevalence of the Brazilian TP53 Founder c.1010G>A (p.Arg337His) in Lung Adenocarcinoma: Is Genotyping Warranted in All Brazilian Patients?

Igor Araujo Vieira; Tiago Finger Andreis; Bruna Vieira Fernandes; Maria Isabel Achatz; Gabriel S Macedo; Daniel Schramek; Patricia Ashton-Prolla

doi:10.3389/fgene.2021.606537

Prevalence of the Brazilian TP53 Founder c.1010G>A (p.Arg337His) in Lung Adenocarcinoma: Is Genotyping Warranted in All Brazilian Patients?

Front Genet. 2021 Feb 2:12:606537. doi: 10.3389/fgene.2021.606537. eCollection 2021.

Authors

Igor Araujo Vieira^{1

2}, Tiago Finger Andreis^{1

2}, Bruna Vieira Fernandes^{2

3}, Maria Isabel Achatz⁴, Gabriel S Macedo^{2

5}, Daniel Schramek^{6

7}, Patricia Ashton-Prolla^{1

2

5}

Affiliations

¹ Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
² Laboratório de Medicina Genômica, Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
³ Curso de Graduação em Biomedicina, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, Brazil.
⁴ Departamento de Oncogenética, Hospital Sírio Libanês, São Paulo, Brazil.
⁵ Programa de Medicina Personalizada, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
⁶ Centre for Molecular and Systems Biology, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada.
⁷ Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.

Abstract

In Southern and Southeastern Brazil, there is a germline pathogenic variant with incomplete penetrance located in the oligomerization domain of TP53, c.1010G>A (p.Arg337His). Due to a founder effect, the variant is present in 0.3% of the general population of the region. Recently, this variant was identified in 4.4 and 8.9% of two apparently unselected, single center case series of Brazilian lung adenocarcinoma (LUAD) patients from the Southeastern and Central regions of the country, respectively. In the present study, our aim was to examine TP53 c.1010G>A allele and genotype frequencies in LUAD samples obtained from patients diagnosed in Southern Brazil. A total of 586 LUAD samples (tumor DNA) recruited from multiple centers in the region were tested, and the mutant allele was identified using TaqMan^® assays in seven cases (7/586, 1.2%) which were submitted to next generation sequencing analyses for confirmation. Somatic EGFR mutations were more frequent in TP53 c.1010G>A carriers than in non-carriers (57.1 vs. 17.6%, respectively). Further studies are needed to confirm if TP53 c.1010G>A is a driver in LUAD carcinogenesis and to verify if there is a combined effect of EGFR and germline TP53 c.1010G>A. Although variant frequency was higher than observed in the general population, it is less than previously reported in LUAD patients from other Brazilian regions. Additional data, producing regional allele frequency information in larger series of patients and including cost-effectiveness analyses, are necessary to determine if TP53 c.1010G>A screening in all Brazilian LUAD patients is justified.

Keywords: Li-Fraumeni syndrome; R337H; TP53 (p.Arg337His); TP53 gene; founder variant; lung adenocarcinoma; non-small cell lung cancer; p53 protein.