Detection of Phosphorylated α-Synuclein—Reply

In Reply We appreciate the Letter by Dr Tu and colleagues about our article on skin biopsy detection of P-SYN. We agree that P-SYN deposition within the skin is variable, and that a single skin biopsy may not be sufficient in all patients. In prior work, we determined that the use of 3 skin biopsies from anatomically different locations optimally balanced sensitivity, specificity, and convenience, while providing information on the topographic distribution of synuclein deposition. In the present study, 28% of cases had only a single skin biopsy positive for P-SYN, 36% had 2 of 3 positive for P-SYN, and 36% had 3 of 3 positive for P-SYN. Thus, we continue to recommend that 3 skin biopsies, from 3 distinct and standard locations, be used.