Genetic testing for 22q11.2 microdeletion in patients with isolated congenital heart disease: a systematic review of diagnostic accuracy studies

• Grant number: 15/06777-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2015
• End date: August 31, 2016
• Field of knowledge: Health Sciences - Collective Health - Public Health
• Principal Investigator: Débora Gusmão Melo
• Grantee: Hendrick Henrique Fernandes Gramasco
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

The 22q11.2 microdeletion syndrome (SD22q11.2) is the most prevalent microdeletion syndrome, consisting usually in heterozygous loss of 3 megabase (Mb) of the chromosse 22 long arm. Its prevalence varies from 1 in 5950 to 1 in 4000 live births. The main organs affected are embryonic derived from the third and fourth gill arches: head and neck muscles and bones, parathyroid glands, thymus and heart. Congenital heart diseases affect 77% of patients, predominantly those involving the outflow tract of the heart (conotruncal). The phenotypic manifestations of the syndrome are very variable and can be quite far frusted and, among the clinical manifestations that raise the suspicion of SD22q11.2, heart diseases are the most relevant. Smaller chromosomal deletions than 5 Mb are not possible to detect by conventional karyotyping (with G banding and level of resolution between 400 and 500 bands), and is necessary to use molecular genetic test for diagnosis of SD22q11.2. With the new molecular techniques for lower cost, the discussion about which patients should be tested for SD22q11.2 is growing. This systematic literature review aims to answer the following question: there is indication to make molecular genetic test for diagnostic of the SD22q11.2 in patients with isolated congenital heart disease? Five databases will be used to do the research, using descriptors chosen by the "Medical Subject Headings", selecting primary studies published between January 2004 and March 2015. The selected studies will be analyzed, synthesized and discussed. Ultimately it is intended to contribute to the synthesis of scientific knowledge on this subject, for the rationalization of incorporation of genomic technology in health and better care for patients with rare diseases.