title: Investigating 22q11.2 deletion and other chromosomal aberrations in fetuses with heart defects detected by prenatal echocardiography.
abstract: Congenital heart disease (CHD) is the most common birth defect and the leading cause of mortality in the first year of life. In fetuses with a heart defect, chromosomal abnormalities are very frequent. Besides aneuploidy, 22q11.2 deletion is one of the most recognizable chromosomal abnormalities causing CHD. The frequency of this abnormality varies in nonselected populations. This study aimed to investigate the incidence of the 22q11.2 deletion and other chromosomal alterations in a Brazilian sample of fetuses with structural cardiac anomalies detected by fetal echocardiography. In a prospective study, 68 fetuses with a heart defect were evaluated. Prenatal detection of cardiac abnormalities led to identification of aneuploidy or structural chromosomal anomaly in 35.3% of these cases. None of the fetuses with apparently normal karyotypes had a 22q11.2 deletion. The heart defects most frequently associated with chromosomal abnormalities were atrioventricular septal defect (AVSD), ventricular septal defect (VSD), and tetralogy of Fallot. Autosomal trisomies 18 and 21 were the most common chromosomal abnormalities. The study results support the strong association of chromosome alterations and cardiac malformation, especially in AVSD and VSD, for which a chromosome investigation is indicated. In fetuses with an isolated conotruncal cardiopathy, fluorescence in situ hybridization (FISH) to investigate a 22q11.2 deletion is not indicated.
authors.affiliation: Departamento de Morfologia e Genética, Universidade Federal de São Paulo, São Paulo, Brazil.
authors.forename: Fernanda Teixeira da Silva
authors.initials: FT
authors.lastname: Bellucco
authors.forename: Sintia Iole Nogueira
authors.initials: SI
authors.lastname: Belangero
authors.forename: Leila Montenegro Silveira
authors.initials: LM
authors.lastname: Farah
authors.forename: Maria Virgínia Lima
authors.initials: MV
authors.lastname: Machado
authors.forename: Adriano Pastor
authors.initials: AP
authors.lastname: Cruz
authors.forename: Lílian Maria
authors.initials: LM
authors.lastname: Lopes
authors.forename: Marco Antonio Borges
authors.initials: MA
authors.lastname: Lopes
authors.forename: Marcelo
authors.initials: M
authors.lastname: Zugaib
authors.forename: Mirlene Cecília
authors.initials: MC
authors.lastname: Cernach
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Melaragno
mesh_terms: D000782:Aneuploidy; D001938:Brazil; D002869:Chromosome Aberrations; D002872:Chromosome Deletion; D002892:Chromosomes, Human, Pair 22; D004452:Echocardiography; D005260:Female; D005318:Fetal Heart / Q000000981:diagnostic imaging*; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging* / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D011247:Pregnancy; D011446:Prospective Studies; D016216:Ultrasonography, Prenatal