Reliable detection of Trisomy 21 using MALDI-TOF mass spectrometry

Abstract

Purpose: Current diagnostic methods for chromosomal abnormalities rely mainly on karyotyping and occasionally fluorescent in situ hybridization or quantitative polymerase chain reaction . We describe an alternative molecular method for the detection of trisomy 21 involving mass spectrometric analysis of single nucleotide polymorphisms.Methods: In collaboration with Sequenom, Inc., 350 blinded amniotic fluid, amniocyte culture, chorionic villus, or amniotic fluid supernatant samples were analyzed for trisomy 21 using SNP analysis and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Peak ratios were calculated for heterozygous genotypes and compared to control values generated from known euploid samples. An analytical algorithm using standard deviations from control values was used to determine the probability of a sample being affected or

MALDI-TOF MS in Prenatal Genomics

“…With no false-positive or falsenegative results using more 'user-friendly' assays, the group recommended the approach as an alternative tool for prenatal diagnosis of trisomy 21; the approach is faster and more simple, and it has a high-throughput capacity compared to the conventional methods. To apply the approach for clinical use, our group performed a large-scale study on a cohort with 350 subjects [86]. Again, our data suggested that MALDI-TOF MS is a robust and reproducible method for the detection of trisomy 21.…”

MALDI-TOF Mass Spectrometry in Clinical Analysis and Research

“…92 The authors pointed out the limitation that the developed method relied on a group of preselected sites, so that it cannot comprehensively detect the highly random mutational patterns in tumor suppressors. 92 MALDI-TOF MS-based nucleic acid analysis has also been applied in genetic diseases, such as trisomy 21 (Down syndrome), a genetic disorder caused by the presence of all or part of the third copy of chromosome 21, 93 genetic deafness inherited from parental generation with genetic and chromosomal abnormalities, 94 and familial adenomatous polyposis (FAP) caused by APC germline mutations, an autosomal dominant colorectal cancer susceptibility syndrome. 97 RNA was extracted from clinical oropharyngeal swabs.…”

Accurate Single-Nucleotide Polymorphism Allele Assignment in Trisomic or Duplicated Regions by Using a Single Base–Extension Assay with MALDI-TOF Mass Spectrometry

“…The iPLEX assay is a multiplexed singlebase extension assay that generates allele-specific products for detection by MALDI-TOF mass spectrometry. Although originally designed for SNP analysis, the assay has also been used for detecting trisomy (2)(3)(4), as well as high-throughput validation of CNVs (5,6 ). Therefore, the iPLEX assay has potential for integrated high-throughput joint analyses of SNPs and CNVs.…”