Aberrant Splicing Caused by a Novel VPS16 Variant Linked to Dystonia Type 30

Dystonia is a hyperkinetic movement disorder characterized by sustained or intermittent involuntary muscle contractions, causing abnormal postures and/or repetitive movements. In this report, we identified a novel heterozygous splice-site variant in VPS16 (NM_022575.4:c.240+3G>C) in a patient with cervical and upper limb dystonia without other neurological or extra-neurological features. Analysis of patient's blood mRNA showed disruption of exon 3/intron 3 donor splice-site, leading to exon 3 skipping, which predictably results in a frameshift [p.(Ala48Valfs*14)]. Despite the scarcity of splice-affecting variants described in VPS16-related dystonia, our report contributes with the first fully characterized variant at the mRNA level.