Identification of submicroscopic chromosomal aberrations in fetuses with increased nuchal translucency and apparently normal karyotype.
Ultrasound Obstet Gynecol
; 38(3): 314-9, 2011 Sep.
Article
em En
| MEDLINE
| ID: mdl-21400624
ABSTRACT
OBJECTIVE:
Fetal nuchal translucency (NT) is assessed by ultrasonography as a screening tool for aneuploidy at 11 to 13 + 6 weeks' gestation. Fetuses with increased NT but apparently normal karyotype are still at higher risk of structural abnormality and a range of genetic syndromes, which may be related to major and submicroscopic chromosomal abnormalities. The aim of this study was to report the prevalence of submicroscopic chromosomal abnormalities in a cohort of apparently euploid fetuses that presented with increased NT.METHODS:
DNA was extracted from stored chorionic villus samples from fetuses found to have increased NT (> 3.5 mm) during first-trimester screening. These samples were examined by microarray-based comparative genomic hybridization (aCGH) using a 44K oligonucleotide array specifically constructed for prenatal screening. Variations in copy number (CNVs) were reported after excluding known non-pathogenic variants and after validation with multiplex ligation-dependent probe amplification (MLPA) or real-time quantitative polymerase chain reaction (qPCR). The prevalence of pathogenic CNVs is reported and the association with NT and other ultrasound findings described.RESULTS:
CNVs were reported in 6/48 (12.5%) cases by aCGH and the microdeletions or microduplications ranged from 1.1 to 7.9 Mb. Five of these were validated by MLPA/real-time qPCR and four (8.3%) were considered to be pathogenic and clinically significant. The incidence of pathogenic CNVs was 20.0% (2/10) among those cases with other sonographic anomalies and 5.3% (2/38) among those without.CONCLUSION:
aCGH allows detection of submicroscopic chromosomal abnormalities, the prevalence of which may be increased in fetuses with NT > 3.5 mm and an apparently normal karyotype.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ultrassonografia Pré-Natal
/
Aberrações Cromossômicas
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Transtornos Cromossômicos
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Medição da Translucência Nucal
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Doenças Fetais
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Cariotipagem
Tipo de estudo:
Diagnostic_studies
/
Etiology_studies
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Prognostic_studies
/
Risk_factors_studies
Limite:
Adult
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Female
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Humans
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Pregnancy
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article