Fig 2: a DNA sequence traces of DNAJC5 Exon 4 of an early stage AD-ANCL patient (top) and wild-type sequence from an age-gender matched control individual (bottom). b Schematic representation of the DNAJC5 gene encoded protein (top) and main transcript (bottom). Mutation p.L115R is highlighted in red.

Fig 3: Abnormal palmitoylation and oligomer formation due to C128Y mutation in vitro. (A) Both the C128Y and L115R mutations had no impact on cell viability. (B) The anti-CSP α antibody (Enzo life, ADI-VAP-SV003-E) used in this study can detect the band at around ∼34 kDa, the molecular weight for endogenous CSP α. The EGFP-tagged CSP α consisted of the amino acids of both EGFP (around 26 kDa) and CSP α and exhibited an apparent molecular weight of around 60 kDa. The palmitoylation process induced a shift in gel migration of approximately 7 kDa (67 kDa is the apparent molecular weight of the palmitoylated species). Furthermore, bands above 180 kDa represent oligomers of CSP α. The L115R mutation reduced the palmitoylation process and also enhanced the amount of oligomer formation. Similarly, but to a lesser extent, the C128Y mutation-induced decreased palmitoylation and triggered oligomer formation, but without impacting abundance detected in endogenous CSP α bands, as quantified in panel C (oligomer), (D) (palmitoylated CSP α), (E) (non- palmitoylated CSP α), (F) (endogenous CSP α), and (G) (ratio of palmitoylated CSP α over non- palmitoylated CSP α). N = 3, all data in the figure are shown as mean ± SEM, each group vs. WT. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001.

Fig 4: Changes of SNAP-25 expression in hippocampal CA3 region due to C128Y mutation. (A) Representative pictures show the decrease of SNAP-25 in the hippocampal CA3 region of mice expressing C128Y mutant CSP α, as quantified in panel B. N = 3, all data in the figure are shown as mean ± SEM, each group vs. vector. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001.

Fig 5: Summary of clinical records of an affected patient with Adult-onset NCL (ANCL). (A) Neuropsychological assessments indicated the cognitive decline in this patient. Scores of each assessment were converted to centesimal systems. (B) Typical MRI imaging of the proband revealed the symmetric atrophy of the bilateral cortex (GCA scale = 2) and hippocampus (MTA scale = 2). (C) Chromatograms of the DNAJC5 genomic DNA sequence showed a coding variant at position c.383 (c.383G > A). (D) Representative pictures of the skin biopsy of sweat gland showed GRODs and curvilinear profile in the affected proband. Magnification is 65,000× in the left and right picture, and 33,000× in the middle one. White arrowhead: the curvilinear profile, white arrows: GRODs. MMSE:, mini-mental state examination; BNT, Boston naming test; CDT, clock drawing test; ACE-R, Addenbrooke’s cognitive examination; GRODs, granular osmiophilic deposits; GCA, global cortical atrophy; MTA, medial temporal lobe atrophy.