Investigation of mutations in the ion channel coding genes KCNJ5, ATP1A1 and ATP2B3 in aldosterone-producing adrenocortical tumors

• Grant number: 16/22721-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2017
• End date: January 31, 2018
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Madson Queiroz Almeida
• Grantee: Kayo Augusto de Almeida Medeiros
• Host Institution: Hospital das Clínicas da Faculdade de Medicina da USP (HCFMUSP). Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

Arterial hypertension (AH) is a major cardiovascular risk factor that affects 10% to 40% of the adult population in industrialized countries. Primary aldosteronism (PA) is the most common form of secondary hypertension with an estimated prevalence of approximately 10% in referred patients. In the last 5 years, considerable advances toward understanding of molecular genetics of aldosterone-producing tumors (aldosteronomas) have been made through the identification of mutations in ion-selective channels that regulate membrane potential. Somatic mutations in KCNJ5 gene, encoding the GIRK4 K+ channel, were identified in 38% of aldosteronomas. More recently, somatic mutations in ATP1A1 gene, encoding a a1 subunit of Na+,K+-ATPase channel, and in the ATP2B3 gene, endoding a Ca+2-ATPase channel, were found in 5,3% and 1,7% of aldosteronomas, respectively. Then, driven mutations were not identified in approximately 46% of aldosteronomas. The aims of our study are: 1) to investigate somatic mutations in KCNJ5, ATP1A1 and ATP2B3 genes in a Brazilian cohort of aldosteronomas; 2) To perform in silico analysis to predict mutation deleterious effects. To achieve these goals, we will employ the following tools: automated sequencing and on-line in silico analysis. We expect that this project will better characterize the spectrum of somatic mutations of Brazilian aldosteronomas. (AU)