Non-Invasive Determination of the Paternal Inheritance in Pregnancies at Risk for β-Thalassaemia by Analyzing...

Area of Science:

• Genetics
• Molecular Biology
• Prenatal Diagnostics

Background:

• Haemoglobinopathies, including β-thalassaemia, are prevalent monogenic disorders globally.
• Current non-invasive prenatal testing (NIPT) is effective for chromosomal abnormalities but limited for monogenic disorders.
• β-thalassaemia is particularly common in Cyprus, necessitating improved screening methods.

Purpose of the Study:

• To develop and evaluate a non-invasive prenatal haplotyping (NIPH) assay for β-thalassaemia screening.
• To utilize cell-free DNA (cfDNA) from maternal plasma for determining paternal inheritance.
• To advance NIPT capabilities for monogenic disorders.

Main Methods:

• Designed a custom, high-density NGS genotyping panel (HAPLONID) with 169 single-nucleotide variants (SNVs).
• Identified highly heterozygous SNVs in the β-globin gene cluster from 96 samples.
• Applied AmpliSeq for Illumina assay to cfDNA from maternal plasma for NIPH analysis.

Main Results:

• Identified 219 highly polymorphic SNVs suitable for haplotyping.
• Successfully determined paternal allele inheritance in 17 families through cfDNA sequencing.
• Achieved 100% success rate in diagnostic interpretation of the NIPH assay.

Conclusions:

• An integrated NGS-NIPT assay for β-thalassaemia has been successfully developed.
• The NIPH assay demonstrates high efficiency and diagnostic accuracy for β-thalassaemia.
• This non-invasive method can reduce the need for invasive prenatal sampling procedures.