Prenatal Phenotypic Analysis of Branchio-Oto-Renal Spectrum Disorder Attributable to EYA1 Gene Pathogenic Variants and Systematic Literature Review.

Background: Branchio-oto-renal (BOR) spectrum disorders are linked to pathogenic variants in the EYA1 gene, presenting significant challenges for prenatal ultrasound screening due to their phenotypic variability and complexity. Understanding these disorders' phenotypic expressions and genetic foundations is crucial.

Methods: Our study included pregnant women who underwent fetal whole-exome sequencing at the Department of Medical Genetics and Prenatal Diagnosis, The Third Affiliated Hospital of Zhengzhou University, Henan, China between January 2023 and March 2024. We identified a novel EYA1 gene pathogenic variant and conducted a systematic literature review of all reported prenatal cases associated with EYA1-related diseases, focusing on the detectability of these conditions in prenatal ultrasound. Additionally, we systematically reviewed case reports related to the EYA1 gene, emphasizing missense pathogenic variants for functional predictions and locus position analysis.

Results: Our research discovered a new pathogenic variant within the EYA1 gene, highlighting the difficulty of detecting BOR spectrum disorder phenotypes through prenatal ultrasound due to their subtle manifestations. We found that amniotic fluid anomalies and cardiac abnormalities are more prevalent in prenatal cases compared to postnatal cases. A critical region within the EYA Homologous Region (eyaHR) was identified, where missense pathogenic variants significantly affect protein stability, indicating a crucial area associated with the severity of phenotypic expression in EYA1 gene-associated disorders.

Conclusion: This study enhances the understanding of the genetic landscape of BOR spectrum disorders and suggests that certain phenotypic markers and genetic regions may be pivotal in improving prenatal screening and diagnosis for EYA1-related diseases.