Paroxysmal kinesigenic dyskinesia caused by 16p11.2 microdeletion

Four cases of paroxysmal kinesigenic dyskinesia (PKD) have been reported in individuals with proximal 16p11.2 microdeletions that include PRRT2.

We describe a fifth patient with PKD, features of Asperger's syndrome, and mild language delays. Sanger sequencing of the PRRT2 gene did not identify any mutations implicated in PKD. However, microarray-based comparative genomic hybridization (aCGH) detected a 533.9-kb deletion on chromosome 16, encompassing over 20 genes and transcripts.

This case underscores the importance of aCGH testing for individuals with PKD who do not have PRRT2 mutations, particularly when developmental delays, speech problems, intellectual disability, and/or autism spectrum disorder are present.