# Noninvasive Prenatal Paternity Testing: A Review on Genetic Markers

## TL;DR

This paper reviews noninvasive prenatal paternity testing, focusing on genetic markers and challenges in forensic use.

## Contribution

The paper highlights the use of SNPs and composite markers for improving NIPPT in forensic contexts.

## Key findings

- cffDNA analysis is central to NIPPT but hindered by maternal DNA dominance.
- SNPs and composite markers show promise in forensic NIPPT.
- MPS has advanced NIPPT but validation and early-stage sensitivity remain challenges.

## Abstract

Noninvasive prenatal paternity testing (NIPPT) is a crucial tool in forensic contexts, particularly in cases involving post-rape pregnancies. It enables judicial authorities and victims to promptly address these situations by determining the paternity of the fetus within a few weeks of pregnancy. NIPPT relies on the analysis of cell-free fetal DNA (cffDNA) found in the maternal bloodstream. However, the abundance of maternal DNA presents a significant challenge in detecting fetal DNA. As a result, research has focused on improving methods for isolating or enriching fetal DNA and, specifically in the context of forensic genetics, on the development of suitable genetic markers. The use of Single Nucleotide Polymorphisms (SNPs) along with novel compound markers or composite multiplexes, has shown promising results. Despite significant advances, partly driven by the increased use of Massive Parallel Sequencing (MPS), challenges remain in validating markers-based NIPPT assays for forensic casework. Further studies are required to enhance the sensitivity of these tests, particularly during the early stages of pregnancy, such as the first trimester. Additionally, improving and standardizing statistical frameworks for result evaluation and interpretation is essential to ensure compatibility with forensic standards.