[Non-invasive fetal RHD genotyping: Validation of the method with 200 patients].

Area of Science:

• Molecular Biology
• Genetics
• Obstetrics

Background:

• Non-invasive fetal RHD genotyping is crucial for managing hemolytic disease of the fetus and newborn in allo-immunized pregnancies.
• Existing methods require invasive procedures, posing risks to both mother and fetus.
• A validated non-invasive method is essential for accurate risk assessment and timely clinical decisions.

Purpose of the Study:

• To validate a non-invasive fetal RHD genotyping method using real-time PCR.
• To assess the accuracy, sensitivity, specificity, and predictive values of the developed method.
• To establish criteria for biological interpretation of genotyping results.

Main Methods:

• Real-time PCR amplification of exons 4, 5, and 10 of the RHD gene.
• Genotyping of fetal DNA from maternal plasma in 200 pregnant women.
• Comparison of genotyping results with infant RH1 phenotype at birth.

Main Results:

• The study validated key performance parameters including sensitivity, specificity, and negative predictive value.
• Correlation studies defined criteria for reliable biological interpretation of RHD genotyping results.
• Identified critical points and limitations, such as low fetal DNA concentration and RHD gene variants.

Conclusions:

• The developed non-invasive fetal RHD genotyping method is validated for clinical application.
• The method aids in assessing the risk of hemolytic disease, enabling informed clinical management.
• Efforts are underway towards accreditation of the genetic laboratory for this testing.