A Prospective Evaluation of the Diagnostic Utility for Low-Coverage Genome Sequencing in Prenatal Samples: A Comparison With Chromosomal Microarray Analysis.

OBJECTIVE

The present study aimed to evaluate the efficacy of LC-GS in detecting clinically relevant chromosomal abnormalities in comparison with conventional CMA within a prenatal context.

METHODS

We conducted a prospective study involving 200 amniotic fluid samples. All specimens were analyzed via LC-GS and traditional tests, including CMA and karyotyping. LC-GS was performed with 3X coverage to gauge its proficiency in identifying copy number variations (CNVs), aneuploidies, regions of homozygosity (ROH), and chromosome mosaicism. Data from both methods were compared to evaluate their sensitivity, specificity, and overall clinical utility.

RESULTS

LC-GS at a depth of 3X identified a total of 77 positive samples, yielding a detection rate of 38.5% (77/200). This included 17 cases of aneuploidy, 36 instances of CNVs, 20 cases linked to ROH, and 8 cases of chromosomal mosaicism. LC-GS demonstrated high concordance with CMA in aneuploidy, CNVs, ROH, and chromosomal mosaicism, achieving a diagnostic yield of 21% (42/200), with additional benefits of reduced cost. Moreover, LC-GS outperformed CMA in terms of resolution for identifying submicroscopic CNVs.

CONCLUSION

LC-GS presents a robust alternative to CMA for prenatal diagnosis, effectively identifying aneuploidies, CNVs, chromosomal mosaicism, and ROH. It delivers comparable sensitivity and specificity in the detection of a wide spectrum of genomic abnormalities.