Cardiac disease burden in DDX3X syndrome

Carlos Gallego-Navarro, Jeanne L. Theis, Radhika Dhamija et al. Under-recognized Cardiac Disease Burden in DDX3X Syndrome: Spectrum of Cardiovascular Abnormalities and Longitudinal Outcomes, 01 April 2026, PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-9059706/v1]

Abstract

Background

DDX3X-syndrome is a rare neurodevelopmental disorder characterized by varying degrees of intellectual disability, predominantly affecting females. We present an institutional cohort supplemented by a systematic literature review, expanding the cardiovascular phenotype of DDX3X-syndrome.

Methods

We conducted a retrospective chart review of patients diagnosed with DDX3X-syndrome at Mayo Clinic. Additionally, we performed a systematic literature review to identify studies reporting cardiovascular abnormalities in patients with DDX3X-syndrome.

Results

A total of 200 patients with DDX3X-syndrome were analyzed, comprising 14 patients from our institutional cohort and 186 patients identified through a systematic review of 9 published studies. Our institutional cohort included 14 patients (12 females and 2 males) from 13 unrelated families diagnosed with DDX3X-syndrome, at a median age of 4.5 years (IQR 1.2–9.5). Echocardiogram was performed on nine patients, and cardiovascular abnormalities were found in 7 out of 9 patients who underwent echocardiography (78%), two of whom had major congenital heart defect (CHD) requiring surgical intervention. At the time of assessment, 13 individuals were still alive, while one had died at age six due to extracardiac complications. The systematic review included 9 studies involving 186 patients, of whom 32 (17.4%, 25 females and 7 males) had reported cardiovascular abnormalities, ranging from simple CHDs to more complex defects.

Conclusion

DDX3X-syndrome carries a significant cardiovascular burden, which is possibly higher than previously reported, including complex congenital heart disease requiring surgical repair. A thorough cardiovascular assessment, including an electrocardiogram and echocardiogram, should be universally recommended for all patients at the time of diagnosis.