Molecular diagnosis of Down syndrome using quantitative APEX-2 microarrays

作者:Oitmaa Eneli*; Peters Maire; Vaidla Kadri; Andreson Reidar; Maegi Reedik; Slavin Georgi; Velthut Agne; Tonisson Neeme; Reimand Tiia; Remm Maido; Schneider Marion; Ounap Katrin; Salumets Andres; Metspalu Andres
来源:Prenatal Diagnosis, 2010, 30(12-13): 1170-1177.
DOI:10.1002/pd.2639

摘要

Objective To develop a new rapid and high-throughput microarray-based prenatal diagnostic test for the detection of trisomy 21 (T21).
Methods The T21 arrayed primer extension-2 (APEX-2) assay discriminates between trisomy and euploid DNA samples by comparing the signal intensities of allelic fractions of heterozygous single nucleotide polymorphisms (SNPs) after APEX reaction. After preliminary validation using DNA samples from Down syndrome patients, we analyzed DNA samples from cultured and uncultured amniocytes and chorionic villus for 90 SNPs with high heterozygosity from the 21(q21.1q22.2) region. Differences in allelic ratios of heterozygous SNPs in normal and T21 individuals were verified by t-test.
Results Analysis of the T21 APEX-2 assay results revealed that 90 SNPs were sufficient for reliable discrimination between T21 and euploid DNA samples (P <= 0.05 for one or both strands). Using 134 clinical samples from cultured or uncultured fetal cells, both the sensitivity and the specificity of the assay were 100%.
Conclusion Our study provides a proof of principle demonstration of the use of the modified APEX-2 assay as a new, fast and reliable method for prenatal diagnosis of fetal T21.

  • 出版日期2010-12