Related Experiment Video
Updated: Jan 18, 2026
09:03
Semiconductor Sequencing for Preimplantation Genetic Testing for Aneuploidy
Published on: August 25, 2019
9.9K
The Diagnostic Utility of Prenatal Microarray in High-Risk Pregnancies: A Single-Center Experience in Enhancing
Abdullatif Bakır1, Mustafa Tarık Alay1, Umut Can Tekbaş1
1Department of Medical Genetics, Ankara Etlik City Hospital, Ankara 06170, Turkey.
Diagnostics (Basel, Switzerland)
|September 13, 2025
Summary
Chromosomal microarray analysis (CMA) significantly improves prenatal diagnosis by detecting small copy number variants (CNVs) missed by conventional karyotyping. This enhances accuracy for fetal structural anomalies, supporting routine genetic evaluation.
Area of Science:
- Genetics
- Prenatal Diagnostics
- Genomic Medicine
Background:
- Prenatal cytogenetic testing is crucial for identifying fetal chromosomal abnormalities.
- Conventional karyotyping detects large rearrangements (>5-10 Mb).
- Chromosomal microarray analysis (CMA) identifies smaller copy number variants (CNVs), increasing diagnostic yield by ~5%.
Purpose of the Study:
- To evaluate the diagnostic utility of CMA compared to conventional karyotyping in prenatal samples.
- To determine the rate of pathogenic CNVs missed by karyotyping.
Main Methods:
- Analysis of 344 prenatal samples using conventional karyotyping and SNP-based CMA (GSA-Cyto on Illumina iScan).
- CNV interpretation using NxClinical v6.0 and curated databases (ClinVar, DECIPHER, OMIM, ClinGen).
- Alignment with GRCh37/hg19 reference genome.
Main Results:
- Chromosomal abnormalities detected in 16.5% (57/344) of cases.
- Includes 39 numerical anomalies and 18 pathogenic/likely pathogenic CNVs.
- 11 CNVs (3.2%) were undetectable by conventional karyotyping.
Conclusions:
- CMA significantly enhances prenatal diagnostic accuracy by detecting submicroscopic CNVs.
- CMA identifies variants missed by conventional methods, improving detection rates.
- Supports the routine use of CMA in prenatal genetic evaluation.
