Hidden Y Chromosome Material and Congenital Cardiovascular Malformations in a Cohort of Turner Syndrome Patients with 45,X Blood Karyotype

Introduction: Bicuspid aortic valve is the most common congenital cardiac malformation (CCM) in adults and is 30-50 times more frequent in Turner syndrome (TS). We hypothesize that both X and Y chromosome dosages contribute to the prevalence of CCM in TS. The recognition of genotype-phenotype correlations may improve risk stratification of patients with 45,X karyotypes who have cryptic Y chromosome mosaicism. Methods: Utilizing data and samples from the UTHealth Turner Syndrome Research Registry, we correlated Y chromosome DNA identified by multiplex quantitative PCR and SNP microarrays with the presence of congenital heart lesions. Results: We identified Y chromosome DNA in more than 10% of registry participants, including 2 participants who had no detectable Y DNA by karyotype or SNP microarray. Conclusions: There were no significant correlations between the presence of Y DNA and CCM.