Prenatal genotype-phenotype correlations in four fetuses with Rubinstein-Taybi syndrome due to EP300 mutations: a case series and literature review.

OBJECTIVE

This study aims to delineate the prenatal ultrasound characteristics of four cases of Rubinstein-Taybi syndrome type 2 (RSTS2) and explore potential associations with this condition as detected through prenatal ultrasound.

METHODS

Whole exome sequencing (WES) and Sanger sequencing were conducted on four fetuses diagnosed with RSTS2. Prenatal ultrasound data were systematically collected and analyzed.

RESULTS

All four fetuses were found to have previously unreported EP300 variants, which were absent from ClinVar and the Human Gene Mutation Database (HGMD). The prenatal ultrasound findings were diverse; in the second trimester, two fetuses exhibited growth parameters below minus two standard deviations (M-2SD). One fetus showed an abnormal foot posture and thickened plantar skin, another was found to have exencephaly in the first trimester, and one case presented with fetal rhabdomyoma.

CONCLUSION

This study prenatal ultrasound phenotypes associated with EP300 variants may add to the phenotypic profile of RSTS2 and could serve as a reference for prenatal diagnosis and counseling.