The prevalence of 16p12.1 microdeletion in patients with left-sided cardiac lesions

Left-sided cardiac lesions have a birth prevalence of approximately 1 in 1000 and have been shown to be heritable in pedigree studies. A large microdeletion at 16p12.1 is associated with childhood developmental delay, and initial studies describing this deletion identified left-sided lesions as an enriched phenotype compared with a control population.

The aim of this study is to determine whether patients with left-sided cardiac lesions have an increased frequency of 16p12.1 microdeletions as compared with control populations.

A cohort of 262 probands with left-sided lesions, including 53 with isolated aortic stenosis/bicuspid aortic valve, 83 with coarctation of the aorta with or without aortic stenosis/bicuspid aortic valve, and 126 with hypoplastic left heart syndrome were assessed for copy number variation at 16p12.1. The control cohort included 595 patients with conotruncal defects as a cardiac control and 971 healthy children.

We detected one patient in the left-sided lesion cohort with a large duplication partially overlapping the reported 16p12.1 microdeletion, along with one patient each in the conotruncal and control cohorts with a deletion in the same region. None of these patients had dysmorphic features, extracardiac malformations, or developmental delay.

In our cohort, structural variation at 16p12.1 was not identified with increased frequency in patients with left-sided lesions as compared with controls.