Novel rearrangements between different chromosomes with direct impact on the diagnosis of 5p-syndrome

Author(s):Show less -

Chehimi, Samar Nasser ; Almeida, Vanessa Tavares ; Nascimento, Amom Mendes ; Zanardo, Evelin Aline ; de Oliveira, Yanca Gasparini ; da Silva Carvalho, Gleyson Francisco ; Wolff, Beatriz Martins ; Montenegro, Marilia Moreira ; de Assuncao, Nilson Antonio ; Kim, Chong Ae ; Kulikowski, Leslie Domenici

• Document type: Journal article
• Source: Clinics; v. 77, p. 6-pg., 2022-05-28.

Abstract

Objectives: Copy Number Variations (CNVs) in the human genome account for common populational variations but can also be responsible for genetic syndromes depending on the affected region. Although a deletion in 5p is responsible for a syndrome with highly recognizable phenotypical features, other chromosomal abnormalities might overlap phenotypes, especially considering that most studies in 5p use traditional cytogenetic techniques and not molecular techniques. Methods: The authors have investigated 29 patients with clinical suspicion of 5p- syndrome using Chromosomal Microarray (CMA), and have gathered information on previous tests, clinical signs, symptoms, and development of the patients. Results: The results showed 23 pure terminal deletions, one interstitial deletion, one deletion followed by a 3 Mb duplication in 5p, three cases of 5p deletion concomitant to duplications larger than 20 Mb in chromosomes 2,9, and 18, and one 5p deletion with a chromosome Y deletion. CMA showed relevant CNVs not typically associated with 5p- that may have contributed to the final phenotype in these patients. Conclusions: The authors have identified three novel rearrangements between chromosomes 5 and 2 (Patient 27), 5 and 18 (Patient 11), and 5 and Y (Patient 22), with breakpoints and overlapped phenotypes that were not previously described. The authors also highlight the need for further molecular investigation using CMA, in different chromosomes beyond chromosome 5 (since those cases did not show only the typical deletion expected for the 5p- syndrome) to explain discordant chromosomal features and overlapped phenotypes to unravel the cause of the syndrome in atypical cases. (AU)

• FAPESP's process: 16/09452-0 - Mapping of DNA break points and investigation of the mechanisms associated with genomic rearrangements using next generation sequencing.
• Grantee: Leslie Domenici Kulikowski
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/02385-0 - Correlation between the Metabolic, Lipidomic and Proteomic Profiles and the 5p Deletion Size of Cri-Du-Chat Syndrome Patients
• Grantee: Nilson Antonio de Assunção
• Support Opportunities: Regular Research Grants