# Genetic Mutations and Non-Genomic Dysregulation in Human Preimplantation Embryo Arrest

## TL;DR

This paper reviews the genetic and non-genetic factors causing embryo arrest during early human development.

## Contribution

It categorizes molecular mechanisms behind embryo arrest into genetic and unexplained causes.

## Key findings

- Genetic mutations disrupt maternal mRNA clearance, spindle assembly, and cell cycle checkpoints.
- Unexplained cases show multi-omics abnormalities like DNA hypermethylation and chromosomal aneuploidy.
- Most clinical cases of embryo arrest remain genetically unexplained.

## Abstract

Human preimplantation embryo arrest (PREMBA) represents a significant clinical hurdle in assisted reproductive technology (ART), in which approximately 10% of in vitro fertilized (IVF) embryos arrest at the cleavage stages. Whole-exome sequencing (WES) studies have discovered numerous genetic mutations associated with preimplantation embryo arrest. These mutations often disrupt critical biological milestones such as maternal mRNA clearance (BTG4, ZFP36L2, ZAR1), subcortical maternal complex (TLE6, PADI6, OOEP, NLRP2, NLRP5, NLRP7, KHDC3L), DNA double-strand break formation and homologous recombination (REC114, TOP6BL, MEI1, MEI4, TRIP13), spindle assembly (TUBB8 and TUBA4A) and cell cycle and checkpoints (FBXO43, MOS, CHEK1, TRIP13, CDC20), as well as nuclear transport and translational regulation (KPNA7, DDOST). However, the cause of most clinical cases remains genetically unexplained. Studies investigating these unexplained arrests have uncovered widespread multi-omics abnormalities, including transcriptional arrest, DNA hypermethylation, higher chromatin accessibility, aberrant histone modification, chromosomal aneuploidy and senescent-like states. This review provides a comprehensive overview of the molecular mechanisms underlying PREMBA, categorized into those that are attributable to known genetic mutations and those with unexplained reasons.