Epsilon globin gene expression in developing human fetal tissues

Area of Science:

• Molecular Biology
• Genetics
• Prenatal Diagnostics

Background:

• Free fetal DNA in maternal plasma enables non-invasive prenatal diagnosis.
• A reliable positive control is needed to confirm fetal nucleic acid presence.

Purpose of the Study:

• To investigate epsilon (ɛ)-globin gene expression as a potential positive control for fetal nucleic acid.
• To compare ɛ-globin mRNA levels in fetal tissues, maternal plasma, and adult samples.

Main Methods:

• Quantitative polymerase chain reaction (qPCR) was used to measure ɛ-globin mRNA.
• RNA was isolated from fetal tissues (marrow, liver, blood, placenta) and blood/plasma from pregnant and non-pregnant adults.
• Samples covered gestational ages from 10-24 weeks.

Main Results:

• ɛ-globin gene expression was detected in all fetal samples and maternal plasma during pregnancy.
• Expression was negligible in non-pregnant adult samples.
• Relative ɛ-globin expression was highest in fetal blood and decreased with gestational age; peak expression in fetal marrow was observed at 15-19 weeks.

Conclusions:

• Fetal ɛ-globin gene expression is significantly higher than adult expression.
• Increased ɛ-globin expression in maternal plasma during pregnancy supports its utility.
• ɛ-globin gene expression can potentially serve as a positive control for fetal nucleic acid in non-invasive prenatal testing.