CDKN1C and Beckwith-Wiedemann syndrome: In fact, the only gene in which a significant number of variants have been identified in 11p15.5-associated imprinting disorders is CDKN1C. Variants in this gene account for nearly 5% of patients with BWS, and it is even higher in familial cases, as confirmed in our family with a CDKN1C frameshift variant (Fig. 2).