CLINICS

Clinics (Sao Paulo). 2017 September; 72(9): 526-537.
doi:10.6061/clinics/2017(09)02

Copyright © 2017 CLINICS

Cytogenomic assessment of the diagnosis of 93 patients with developmental delay and multiple congenital abnormalities: The Brazilian experience

Évelin Aline Zanardo I * , Roberta Lelis Dutra I , Flavia Balbo Piazzon I , Alexandre Torchio Dias I , Gil Monteiro Novo-Filho I , Amom Mendes Nascimento I , Marília Moreira Montenegro I , Jullian Gabriel Damasceno I , Fabrícia Andreia Rosa Madia I , Thaís Virgínia Moura Machado da Costa I , Maria Isabel Melaragno II , Chong Ae Kim III , Leslie Domenici Kulikowski I

Laboratorio de Citogenomica, Departamento de Patologia, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Sao Paulo, SP, BR

Departamento de Morfologia e Genetica, Universidade Federal de Sao Paulo, Sao Paulo, SP, BR

Unidade de Genetica, Departamento de Pediatria, Instituto da Crianca, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR

*Corresponding author. E-mail: evelinzanardo@yahoo.com.br

received December 14, 2016; revised February 21, 2017; accepted May 4, 2017.

Abstract

OBJECTIVE:

The human genome contains several types of variations, such as copy number variations, that can generate specific clinical abnormalities. Different techniques are used to detect these changes, and obtaining an unequivocal diagnosis is important to understand the physiopathology of the diseases. The objective of this study was to assess the diagnostic capacity of multiplex ligation-dependent probe amplification and array techniques for etiologic diagnosis of syndromic patients.

METHODS:

We analyzed 93 patients with developmental delay and multiple congenital abnormalities using multiplex ligation-dependent probe amplifications and arrays.

RESULTS:

Multiplex ligation-dependent probe amplification using different kits revealed several changes in approximately 33.3% of patients. The use of arrays with different platforms showed an approximately 53.75% detection rate for at least one pathogenic change and a 46.25% detection rate for patients with benign changes. A concomitant assessment of the two techniques showed an approximately 97.8% rate of concordance, although the results were not the same in all cases. In contrast with the array results, the MLPA technique detected ∼70.6% of pathogenic changes.

CONCLUSION:

The obtained results corroborated data reported in the literature, but the overall detection rate was higher than the rates previously reported, due in part to the criteria used to select patients. Although arrays are the most efficient tool for diagnosis, they are not always suitable as a first-line diagnostic approach because of their high cost for large-scale use in developing countries. Thus, clinical and laboratory interactions with skilled technicians are required to target patients for the most effective and beneficial molecular diagnosis.

Keywords: Cytogenomic Techniques, MLPA, Array, Developmental Delay, Multiple Congenital Abnormalities


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