Size fractionation of cell-free DNA in maternal plasma improves the detection of a paternally inherited beta-thalassemia point mutation by MALDI-TOF mass spectrometry.

Abstract

OBJECTIVES:

The selective enrichment of cell-free fetal DNA in maternal plasma by size fractionation leads to the improved detection of paternally inherited fetal point mutations when using conventional, real-time PCR, or as has more recently been shown by MALDI-TOF mass spectrometry. We have now examined the use of size fractionation in conjunction with mass spectrometry for the detection of a paternally inherited codon 39 mutation of the beta-globin gene.

METHODS:

Maternal plasma was obtained from an early second trimester pregnancy at risk for beta-thalassemia, where the father carried the codon 39 mutation and the mother was a carrier for the IVSI-110 mutation of the beta-globin gene. Cell-free DNA was analyzed by mutation-specific PCR and MALDI-TOF mass spectrometry for the presence of the codon 39 mutation. A comparison was made between total cell-free DNA and that which had been enriched for a size of 100-300 bp.

RESULTS:

The paternally inherited codon 39 mutant allele was detectable in both cell-free DNA preparations, but the signal was much more pronounced and precise in the size-fractionated sample.

CONCLUSIONS:

Size fractionation of cell-free DNA may lead to the improved non-invasive detection of fetal point mutations for beta-thalassemia by MALDI-TOF mass spectrometry.

• Authors: Ying Li, Edoardo Di Naro, Angeloantonio Vitucci, Simon Grill, Xiao Yan Zhong, Wolfgang Holzgreve, Sinuhe Hahn
• Journal: Fetal diagnosis and therapy (Fetal Diagn Ther) Vol. 25 Issue 2 Pg. 246-9 ( 2009) ISSN: 1421-9964 [Electronic] Switzerland
• PMID: 19506384 (Publication Type: Case Reports, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright (c) 2009 S. Karger AG, Basel.

Chemical References

• DNA

Topics

• Adult
• Chemical Fractionation
• DNA (blood)
• Female
• Fetus (cytology)
• Genetic Predisposition to Disease
• Genetic Testing
• Humans
• Male
• Maternal-Fetal Exchange
• Point Mutation
• Pregnancy
• Prenatal Diagnosis
• Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
• beta-Thalassemia (genetics)