Introducing array comparative genomic hybridization into routine prenatal diagnosis practice: a prospective study on...

Area of Science:

• Genetics
• Prenatal Diagnosis
• Genomic Medicine

Background:

• Conventional karyotyping is the standard for prenatal diagnosis of chromosomal abnormalities.
• Array-based comparative genomic hybridization (aCGH) offers higher resolution for detecting copy number variations.
• Evaluating aCGH as a primary diagnostic tool requires assessing its feasibility and diagnostic yield compared to current methods.

Purpose of the Study:

• To determine if array-based comparative genomic hybridization (aCGH) can be effectively used as a first-line prenatal diagnostic test.
• To compare the diagnostic accuracy of aCGH against conventional karyotyping in prenatal samples.

Main Methods:

• A prospective study involving 1037 prenatal samples obtained via amniocentesis or chorionic villus sampling.
• Parallel testing of all samples using both aCGH and standard G-banding karyotyping.
• Analysis included amniotic fluid, chorionic villus samples, and cultured amniocytes.

Main Results:

• Chromosomal abnormalities were detected in 3.3% of samples.
• aCGH identified pathogenic copy number variations missed by conventional karyotyping in 26.5% of abnormal cases (9 out of 34).
• aCGH detected chromosomal mosaicism at levels as low as 10% and showed complete concordance with karyotyping, except for two cases uniquely diagnosed by aCGH.

Conclusions:

• Array-based comparative genomic hybridization (aCGH) is a superior diagnostic tool for prenatal detection of chromosomal abnormalities.
• The study provides evidence supporting the feasibility of integrating aCGH into routine prenatal diagnosis as a first-line test.
• Further large-scale studies are recommended to solidify aCGH's role in prenatal genetic screening.