Finally, myocardial 123I-metaiodobenzylguanidine scintigraphy showed a marked reduction of tracer accumulation in PD patients carrying GBA1 mutation compared to iPD patients (Li et al., 2014), suggesting that neurodegeneration of myocardial nerve fibers had begun before clinical presentation and/or that disease progression is more rapid in this population. The gene discussed is GBA1; the disease is Parkinson disease.