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Exome study in families with clinical diagnosis of MODY (Maturity-Onset Diabetes of the Young) and Neonatal Diabetes

Grant number: 17/14703-4
Support type:Scholarships in Brazil - Doctorate
Effective date (Start): November 01, 2017
Effective date (End): October 31, 2020
Field of knowledge:Biological Sciences - Genetics - Human and Medical Genetics
Principal Investigator:Milena Gurgel Teles Bezerra
Grantee:Lucas Santos de Santana
Home Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Diabetes Mellitus comprises a group of metabolic alterations characterized by hyperglycemia resulting from defects in insulin secretion and/or its function. In Monogenic Diabetes, which corresponds to 1-4% of all diabetic cases diagnosed in childhood, the phenotype is caused by allelic changes in specific loci. It has an extremely heterogeneous genetic etiology, with more than 40 subtypes already described, each with its characteristic phenotype and inheritance pattern, such as: MODY (Maturity-Onset Diabetes of the Young), Neonatal Diabetes Mellitus, Mitochondrial Diabetes, Genetic Lipodystrophy and Wolfram Syndrome. Confirmation of the clinical diagnosis of the different subtypes of Monogenic Diabetes is performed by gene sequencing. Molecular genetic study is extremely important not only for diagnostic confirmation but also for identification of the phenotypic subtype, prediction of probable clinical course and adequate genetic counseling. Studies in different groups of patients with Monogenic Diabetes demonstrate that the genes currently related to the phenotype still do not explain 100% of clinically diagnosed cases. In the last five years, the Monogenic Diabetes Group of the Faculdade de Medicina da Universidade de São Paulo has established a new screening and diagnosis center for Monogenic Diabetes in Brazil, with an outpatient clinic and laboratory dedicated to receiving, monitoring and investigation of patients. One of the current research lines is dedicated to the investigation of individuals with MODY and Neonatal Diabetes Mellitus; most prevalent subtypes of these monogenic forms of diabetes and which have great etiological overlap, with innumerable genes associated in common. This study aims to perform Whole Exome Sequencing in patients clinically diagnosed with MODY and Neonatal Diabetes Mellitus, who have negative genetic test in all genes already described associated with their respective phenotype. One hundred and thirty-nine probands with clinical diagnosis of MODY and Neonatal Diabetes Mellitus were investigated using 2 different approaches: Sanger sequencing and Targeted sequencing. In 29% of the cases (40/139) no candidate allelic variant was identified, and the exome study is proposed for those in which at least the trio (parents-proband) is available. An extended genomic investigation of these individuals may allow the identification of causal genotype-phenotype associations in genes not yet associated with these phenotypes. (AU)

Scientific publications
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
DE SANTANA, LUCAS S.; CAETANO, LILIAN A.; COSTA-RIQUETTO, ALINE D.; FRANCO, PEDRO C.; DOTTO, RENATA P.; REIS, ANDRE F.; WEINERT, LETICIA S.; SILVEIRO, SANDRA P.; VENDRAMINI, MARCIO F.; DO PRADO, FLAVIENE A.; ABRAHAO, GIOVANNA C. P.; DE ALMEIDA, ANA GREGORIA F. P.; RODRIGUES TAVARES, MARIA DA G.; GONCALVES, WAGNER RODRIGO B.; SANTOMAURO JUNIOR, AUGUSTO C.; HALPERN, BRUNO; JORGE, ALEXANDER A. L.; NERY, MARCIA; TELES, MILENA G. Targeted sequencing identifies novel variants in common and rare MODY genes. MOLECULAR GENETICS & GENOMIC MEDICINE, v. 7, n. 12 DEC 2019. Web of Science Citations: 0.

Please report errors in scientific publications list by writing to: cdi@fapesp.br.