In 2010, a heterozygous mutation of PDE8B was first described in a German family as causative of autosomal dominant striatal degeneration (ADSD), a rare genetic disorder that is characterized by slowly progressive dysarthria, brisk deep tendon reflexes, and mild parkinsonism without tremor and poor response to l‐dopa treatment.7 This evidence concerns the gene PDE8B and Parkinson disease.