Sensitive Monogenic Noninvasive Prenatal Diagnosis by Targeted Haplotyping

Area of Science:

• Genetics
• Molecular Biology
• Prenatal Diagnostics

Background:

• Cell-free fetal DNA (cffDNA) in maternal blood offers non-invasive prenatal testing opportunities.
• Maternal cell-free DNA (cfDNA) complicates direct observation of fetal alleles for monogenic diseases.
• Current non-invasive prenatal diagnostics (NIPD) for monogenic diseases lack routine clinical application.

Purpose of the Study:

• To develop and validate a novel method for non-invasive prenatal diagnosis of monogenic diseases.
• To enable accurate prediction of fetal gene inheritance using maternal and parental blood samples.
• To establish a clinically applicable prenatal diagnostic test for severe monogenic conditions.

Main Methods:

• Monogenic NIPD (MG-NIPD) utilizes targeted locus amplification (TLA) for parental haplotyping.
• Capture probe-based targeted sequencing of maternal cfDNA.
• Tailored statistical analysis to predict fetal gene inheritance from cffDNA.

Main Results:

• MG-NIPD successfully predicted inherited alleles in 18 pregnancies with >98% confidence.
• Accurate predictions were achieved as early as 8 weeks of gestation.
• Results were validated against fetal material from invasive procedures, confirming parental haplotyping accuracy.

Conclusions:

• MG-NIPD is a robust and accurate method for non-invasive prenatal diagnosis of monogenic diseases.
• The technique requires standard instrumentation and is suitable for clinical implementation.
• MG-NIPD provides a simple blood-draw-based prenatal diagnostic option for families at risk of severe monogenic disorders.