Single Nucleotide Polymorphism-Based Noninvasive Prenatal Testing: Experience in India

Area of Science:

• Genetics
• Molecular Biology
• Obstetrics

Background:

• Noninvasive prenatal testing (NIPT) has transformed prenatal screening for chromosomal aneuploidies globally.
• Implementation in developing nations, including India, has been inconsistent.
• Genetic variations across populations necessitate localized performance evaluations of NIPT.

Purpose of the Study:

• To assess the performance of single-nucleotide polymorphism (SNP)-based NIPT in the Indian population.
• To evaluate NIPT's accuracy in detecting chromosomal aneuploidies in an Indian cohort.

Main Methods:

• The Panorama™ NIPT assay was utilized in 516 pregnancies with intermediate-to-high risk results from conventional screening.
• Results were validated through invasive diagnostic testing or postnatal clinical evaluation.
• Analysis included calculation of sensitivity, specificity, and positive predictive values.

Main Results:

• A success rate of 97.7% was achieved, with 499 out of 511 samples yielding results.
• 100% sensitivity was observed for trisomies 21, 18, 13, and sex chromosomal abnormalities.
• Specificity ranged from 99.3% to 100%, with a positive predictive value of 85.7% for common trisomies and monosomy X.

Conclusions:

• This study represents the first detailed report on NIPT experience in India.
• SNP-based NIPT demonstrated performance comparable to global benchmarks.
• NIPT is a viable and accurate tool for prenatal screening in India.