Characterization of apparently balanced chromosomal rearrangements and its association with the phenotype of carriers: breakpoint mapping by mate pair sequencing

• Grant number: 13/01146-9
• Support type: Scholarships abroad - Research Internship - Doctorate
• Effective date (Start): August 01, 2013
• Effective date (End): July 31, 2014
• Field of knowledge: Biological Sciences - Genetics - Human and Medical Genetics
• Principal researcher: Angela Maria Vianna Morgante
• Grantee: Ana Carolina dos Santos Fonseca
• Supervisor abroad: Niels Tommerup
• Home Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Research place: University of Copenhagen, Denmark
• Associated to the scholarship: 11/14293-4 - Characterization of apparently balanced chromosomal rearrangements and of its association to the phenotype of carriers, BP.DR

Abstract

The majority of carriers of apparently balanced chromosomal rearrangements are phenotypically normal, but about 7% of these rearrangements are associated with birth defects. In our ongoing PhD project (FAPESP 2011/14293-4), we aim at contributing to the understanding of the causative mechanisms of phenotypic abnormalities in carriers of balanced chromosomal rearrangements. Disclosing the mechanism of formation of these chromosomal rearrangements is another objective of the study. Apparently balanced de novo rearrangements and balanced rearrangements inherited from phenotypically normal parents in patients with developmental disorders of unknown etiology are under study. In the first year of our PhD project,we investigated 12 de novo rearrangements. Cryptic genomic imbalances in the rearranged chromosomes were identified in four of them, and two other rearrangements were associated with additional breakpoints. While FISH and a-CGH revealed the complexity of some of the rearrangements we have studied, precise determination of breakpoints at the base-pair level is crucial for accurate genotype-phenotype correlations, which are dependent on the extent of genes or regulatory regions altered by the rearrangements. In addition, precise determination of breakpoints gives insights into the mechanisms underlying the rearrangement formation. The aim of our visit to the laboratory of Professor Niels Tommerup, at the University of Copenhagen, Denmark, will be to use next generation mate-pair sequencing to characterizethe breakpoints and junction fragments in balanced chromosome rearrangements, to the base-pair resolution. The research group of Professor Niels Tommerup established the method aiming at the systematic mapping of apparently balanced rearrangements ascertained worldwide, as a resource for large scale genotype-phenotype delineation in man. This project includes the engagement of PhD students from the participant laboratories, and transfer of technology. Dr. Angela Morgante was invited to join this effort and to coordinate the participation of other Brazilian laboratories. (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)

MEHRJOUY, MANA M.; FONSECA, ANA CAROLINA S.; EHMKE, NADJA; PASKULIN, GIORGIO; NOVELLI, ANTONIO; BENEDICENTI, FRANCESCO; MENCARELLI, MARIA ANTONIETTA; RENIERI, ALESSANDRA; BUSA, TIFFANY; MISSIRIAN, CHANTAL; HANSEN, CLAUS; ABE, KIKUE TERADA; SPECK-MARTINS, CARLOS EDUARDO; VIANNA-MORGANTE, ANGELA M.; BAK, MADS; TOMMERUP, NIELS. Regulatory variants of FOXG1 in the context of its topological domain organisation. European Journal of Human Genetics, v. 26, n. 2, p. 186-196, FEB 2018. Web of Science Citations: 4.

FONSECA, ANA CAROLINA S.; BONALDI, ADRIANO; FONSECA, SIMONE A. S.; OTTO, PAULO A.; KOK, FERNANDO; BAK, MADS; TOMMERUP, NIELS; VIANNA-MORGANTE, ANGELA M. The segregation of different submicroscopic imbalances underlying the clinical variability associated with a familial karyotypically balanced translocation. MOLECULAR CYTOGENETICS, v. 8, DEC 30 2015. Web of Science Citations: 2.