Clinical application of single nucleotide polymorphism array in prenatal diagnosis: Experience with 8753 samples

Area of Science:

• Genetics
• Prenatal Diagnostics
• Genomic Analysis

Background:

• Single nucleotide polymorphism (SNP) array technology is increasingly utilized in prenatal diagnosis.
• Assessing the clinical utility of SNP array for fetal chromosomal anomaly detection is crucial.

Purpose of the Study:

• Evaluate the clinical significance and diagnostic yield of SNP array in a large cohort of high-risk pregnancies.
• Determine the detection rates of chromosomal abnormalities using SNP array across different risk indication groups.

Main Methods:

• Retrospective analysis of 8753 pregnant women with high-risk prenatal indications.
• Collection and review of demographic data, chromosomal abnormality findings, and follow-up results.
• Comparison of SNP array results with traditional karyotyping.

Main Results:

• SNP array identified chromosomal abnormalities in 16.9% of cases, including aneuploidy (7.7%) and copy number variations (CNVs) (4.2-4.4%).
• Higher abnormality detection rates were observed with increasing numbers of risk indications (15.3% to 38.4%) and positive noninvasive prenatal testing (NIPT) results (38.8%).
• SNP array showed an 89.0% concordance with karyotyping, detecting microdeletions/microduplications missed by karyotyping, while missing some structural abnormalities and low-level mosaicism.

Conclusions:

• SNP array is a valuable technology for prenatal diagnosis, demonstrating varying detection rates based on maternal risk factors.
• Combining SNP array with traditional karyotyping enhances prenatal diagnostic information and accuracy.