ELN and Williams syndrome: This variant was classified as a variant of uncertain significance for the following reasons: this variant had not been reported in the literature in individuals affected with ELN-related conditions (autosomal dominant supravalvular aortic stenosis, autosomal dominant cutis laxa, and Williams syndrome),2, 3, 4, 5 presence in population databases (Genome Aggregation Database frequency of 0.006%), and an internal functional study, indicating that the variant is not expected to disrupt ELN protein function with a negative predictive value of 80%.