aortic dissection; bicuspid aortic valve; karyotype; magnetic resonance imaging; Turner syndrome

Background: Bicuspid aortic valve (BAV) represents one of the strongest risk factors for aortic dissection in Turner syndrome (TS). An exact relation between the occurrence of BAV and a particular karyotype has not been established yet. The aim of this study was to determine the association between karyotype and prevalence of BAV. Methods: Sixty-seven TS patients aged between 6.6 and 32.5 years underwent cardiac magnetic resonance imaging (MRI) study. They were divided into four cytogenetic subgroups -45, X karyotype (n = 27); 45, X/46, XX mosaicism (n = 17); structural abnormalities of the X chromosome (n = 10); and 45, X/structural abnormality of the X chromosome mosaicism (n = 13). Prevalence of BAV and odds ratio (OR) compared with the general population in the whole study group, and statistical comparison of prevalences of BAV among the individual subgroups were determined. Results: Prevalence of BAV in the whole study group was established as 28.4% [OR 208.3 (95% CI -103.8-418.0); p-value < 0.0001]. Individuals with 45, X karyotype had the highest prevalence of BAV -40.7%, p-value < 0.0001. Presence of any 45, X cell line in karyotype significantly predisposed to BAV (p-value = 0.05). Conclusions: The 45, X karyotype is associated with the highest prevalence of BAV. Also, the presence of the 45, X cell line in any mosaic karyotype increases the probability of BAV.