SNCA and Alzheimer disease: The unaffected concentrations of established biomarkers for conditions often misdiagnosed as iNPH, such as MCI due to AD (indicated by CSF levels of Aβ1−42/Aβ1−40, p-tau181, secernin-1 [SCRN1], and microtubule-associated protein tau [MAPT]) and Parkinsonian syndrome (marked by α-synuclein [SNCA] and DOPA decarboxylase [DDC]), underscore the phenotypic consistency of the iNPH participants in our study [33, 34].