PRRT2 and Intellectual disability: One child (case 2) with SeLIE and a heterozygous PRRT2 variant had nonepileptic head drops consistent with benign myoclonus of infancy, which has been previously described in only 1 case in the literature.27 Similar to the literature, cognitive development was normal in all children,17 except for 1 child with 16p11.2 microdeletion (case 11) who had intellectual disability with autistic features.