Cardiovascular Manifestations of Turner Syndrome: Phenotypic Differences Between Karyotype Subtypes

Abstract

Turner syndrome (TS) is a genetic disorder presenting in phenotypic females with total or partial monosomy of the X chromosome. Cardiovascular abnormalities are common, including congenital heart defects (CHD) and aortic dilation. Although mosaic TS is suspected to have less severe phenotype as compared to non-mosaic TS, differences in cardiovascular manifestations between karyotypes are not well studied. This is a single-center retrospective cohort study including patients with TS seen from 2000 to 2022. Demographic data, chromosomal analysis, and imaging were reviewed. Karyotypes were categorized as monosomy X (45X), 45X mosaicism, isochromosome Xq, partial X deletions, ring X (r(X)), TS with Y material, and others. Prevalence of CHD and aortic dilation were compared between monosomy X and other subtypes using Pearson's chi-square test and Welch two-sample t-test. We included 182 TS patients with median age 18 (range 4-33) years. CHD was more common in monosomy X as compared with others (61.4% vs. 26.8%, p < 0.001), including bicuspid aortic valve (44.3% vs. 16.1%, p < 0.001), partial anomalous pulmonary venous return (12.9% vs. 2.7%, p = 0.023), persistent left superior vena cava (12.9% vs. 1.8%, p = 0.008), and coarctation of the aorta (20.0% vs. 4.5%, p = 0.003). Cardiac surgery (24.3% vs. 8.9%, p = 0.017) was more prevalent in the monosomy X group. There was no statistically significant difference for presence of aortic dilation (7.1% vs 1.8%, p = 0.187). Although CHD and need for cardiac surgery are more common in TS with monosomy X as compared to others, all TS subtypes may have similar risk of developing aortic dilation. All TS patients should have similar cardiovascular surveillance testing to monitor for aortic dilation.

Keywords: Aortic dilation; Bicuspid aortic valve; Coarctation of the aorta; Congenital heart disease; Turner syndrome.