HIP1 and Williams syndrome: Williams-Beuren syndrome is a multisystem disorder caused by a heterozygous deletion on chromosome 7q11.23 not typically including HIP1 and YWHAG, characterized by distinctive facial features, supravalvular aortic stenosis and mild-to-moderate intellectual disability.6 Seizures are rarely reported with the common deletion, but are more often described in patients with larger atypical deletions including HIP1 and YWHAG, as well as MAGI2, who present with more pronounced neurological features than typically seen in Williams-Beuren syndrome due to common deletions.2,5,12,16