Characterization of apparently balanced chromosomal rearrangements and of its association to the phenotype of carriers

• Grant number: 11/14293-4
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: November 01, 2011
• End date: October 31, 2015
• Field of knowledge: Biological Sciences - Genetics - Human and Medical Genetics
• Principal Investigator: Angela Maria Vianna Morgante
• Grantee: Ana Carolina dos Santos Fonseca
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 98/14254-2 - The Human Genome Research Center, AP.CEPID
• Associated scholarship(s): 13/01146-9 - Characterization of apparently balanced chromosomal rearrangements and its association with the phenotype of carriers: breakpoint mapping by mate pair sequencing, BE.EP.DR

Abstract

The majority of carriers of apparently balanced chromosomal rearrangements are phenotypically normal, but about 7% of these rearrangements are associated with clinical abnormalities at birth. Intragenic break, variable expression of genes near the breakpoint due to position effect, generation of chimeric genes and uniparental disomy are pathogenic mechanisms classically proposed. Recently it was shown that submicroscopic deletions and duplications in the rearranged chromosomes could be the underlying cause of phenotypic abnormalities. Cryptic genomic imbalances were also identified as de novo mutations in patients who inherited the balanced rearrangement from a phenotypically normal parent. In the present study we aim at contributing to the understanding of mechanisms that lead to 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 a phenotypically normal parent in patients with developmental anomalies of unknown etiology will be studied. The study will also include phenotypically normal individuals with balanced rearrangements. The differences between balanced rearrangements in phenotypically normal and abnormal cohorts can reveal characteristics of balanced chromosomal rearrangements that cause phenotypic abnormalities. The breakpoints of the rearrangements will be mapped by fluorescence in situ hybridization (FISH) and the presence of cryptic genomic imbalances will be investigated by array comparative genomic hybridization (a-CGH). The parental origin of the imbalances will be determined by microsatellite genotyping.

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)

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. (13/01146-9, 13/08028-1, 11/14293-4)

MEHRJOUY, MANA M.; FONSECA, ANA CAROLINA S.; EHMKE, NADJA; PASKULIN, GIORGIO; NOVELLI, ANTONIO; BENEDICENTI, FRANCESCO; MENCARELLI, MARIA ANTONIETTA; RENIERI, ALESSANDRA; BUSA, TIFFANY; MISSIRIAN, CHANTAL; et al. 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. (11/14293-4, 13/08028-1, 13/01146-9)

FONSECA, ANA CAROLINA S.; BONALDI, ADRIANO; BERTOLA, DEBORA R.; KIM, CHONG A.; OTTO, PAULO A.; VIANNA-MORGANTE, ANGELA M.. The clinical impact of chromosomal rearrangements with breakpoints upstream of the SOX9 gene: two novel de novo balanced translocations associated with acampomelic campomelic dysplasia. BMC MEDICAL GENETICS, v. 14, MAY 7 2013. (09/03480-8, 11/12486-0, 11/14293-4)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

FONSECA, Ana Carolina dos Santos. Characterization of karyotypically balanced chromosomal rearrangements associated with clinical features. 2016. Doctoral Thesis - Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) São Paulo.