KCNJ8 and hypertrichotic osteochondrodysplasia Cantu type: Gain-of-function mutations in Kir6.1 or SUR2B result in Cantu syndrome, an autosomal dominant disorder that affects multiple organ systems, including the cardiovascular system (Harakalova et al., 2012; van Bon et al., 2012; Brownstein et al., 2013; Li et al., 2013; Cooper et al., 2014) More than half of Cantu patients are born with symptomatic PDA (Nichols, 2023).