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Inheritance

2

Autosomal recessive inheritance HP:0000007

The two deeply modeled recessive branches are CLN6-related Kufs A and CTSF-related CLN13; CTSF explains only a minority of phenotype-defined Type B cases and also causes other adult presentations.

Autosomal recessive inheritance

Show evidence (2 references)

PMID:21549341 SUPPORT Human Clinical

"We mapped four families with Kufs disease for whom there was good evidence of autosomal-recessive inheritance"

The Arsov et al. linkage study establishes autosomal recessive inheritance in CLN6-related Kufs disease.

PMID:23297359 SUPPORT Human Clinical

"We performed genome-wide linkage mapping of two families with recessive Type B Kufs disease"

Human family linkage establishes recessive inheritance for the CTSF-related CLN13 branch discovered in Type B Kufs families.

Autosomal dominant inheritance HP:0000006

The CLN4 form of adult NCL is caused by autosomal dominant pathogenic variants in DNAJC5.

Autosomal dominant inheritance

Show evidence (1 reference)

PMID:21820099 SUPPORT Human Clinical

"Autosomal-dominant adult-onset neuronal ceroid lipofuscinosis (ANCL) is characterized by accumulation of autofluorescent storage material in neural tissues and neurodegeneration and has an age of onset in the third decade of life or later."

Noskova et al. establish DNAJC5/CLN4 as the autosomal dominant adult form of NCL.

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Subtypes

3

CLN6-related Kufs disease Type A

CLN6 hgnc:2077

The recessive CLN6-related adult branch presents as progressive myoclonus epilepsy with debilitating myoclonus, later dementia, and ataxia. It is distinguished from dominant DNAJC5-related CLN4 despite overlapping myoclonus and seizure phenotypes.

Show evidence (1 reference)

PMID:21549341 SUPPORT Human Clinical

"Mutations in CLN6 are the major cause of recessive Kufs type A disease."

The human family study establishes CLN6 as the major cause of recessive Kufs A.

CTSF-related neuronal ceroid lipofuscinosis type 13 (CLN13)

CTSF hgnc:2531

A recessive adult-NCL branch originally discovered in Type B Kufs disease. A 2025 systematic review of 20 reported patients found that most did not have classic Type B disease and proposed additional Type B and Kufs C presentations. CTSF therefore should not be treated either as an exhaustive explanation of phenotype-defined Type B Kufs disease or as restricted to that phenotype.

Show evidence (2 references)

PMID:23297359 SUPPORT Human Clinical

"Although CTSF mutations account for a minority of cases of type B Kufs, CTSF screening should be considered in cases with early-onset dementia and may avoid the need for invasive biopsies."

The discovery cohort establishes CTSF while explicitly limiting it to a minority of Type B cases.

PMID:39720560 SUPPORT Human Clinical

"Most patients with CLN13 (14/20) did not present with classic KSB (KSB-I)."

The systematic review shows that CTSF-related CLN13 is broader than classic Type B Kufs disease.

DNAJC5-related CLN4 (Parry disease)

DNAJC5 hgnc:16235

The autosomal dominant adult-NCL branch caused by DNAJC5 variants. It is modeled separately from recessive CLN6 Kufs A and CTSF CLN13 under the modern gene-first classification, while retaining Parry disease as its clinical eponym.

Show evidence (2 references)

PMID:21820099 SUPPORT Human Clinical

"we identified in five individuals one of two disease-causing mutations, c.346_348delCTC and c.344T>G, in DNAJC5 encoding cysteine-string protein alpha (CSPα)."

The original human genetic study identifies pathogenic DNAJC5 variants in dominant adult NCL.

PMID:23838030 SUPPORT Other

"There is an autosomal dominant form of neuronal ceroid lipofuscinosis, now classified as CLN4 disease, that is due to mutation in the DNAJC5 gene that codes for a cysteine string protein. This has also been referred to as “Parry disease,” named after the family in which it was first described."

A classification review supports the gene-first CLN4 label and Parry eponym.

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Discussions and Knowledge Gaps

1

Is visual loss a characteristic phenotype of DNAJC5-related CLN4?

CONTROVERSY RESOLVED cln4_visual_loss_classification_conflict

Attached to

has_subtypes#DNAJC5 CLN4

A 2013 clinical classification review states that visual loss is absent in CLN4, whereas a 2022 overview table lists visual failure. Recording both statements preserves the source conflict without promoting the isolated table cell to a positive phenotype assertion.

Resolution: Visual loss is not curated as a characteristic CLN4 phenotype; the explicit disease narrative is preferred over the conflicting overview-table cell.

Show evidence (2 references)

PMID:23838030 REFUTE Other

"There is no visual loss in CLN4 disease."

The disease-specific CLN4 narrative explicitly refutes visual loss as a characteristic feature.

PMID:35359645 SUPPORT Other

"Parry/CLN4 #162350 AD 20q13.33 CLN4/DNAJC5 CSPα (soluble protein): cytosol (vesicular membrane) 3rd-5th Seizures, action myoclonus, visual failure"

The overview table supplies the conflicting positive phrase but no disease-specific supporting narrative.

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Pathophysiology

7

CLN6 EGRESS Complex Lysosomal Enzyme Trafficking Defect

CLN6 is an endoplasmic-reticulum-associated component of the CLN6-CLN8 EGRESS complex that recruits lysosomal enzymes at the ER and promotes their Golgi transfer. CLN6 deficiency impairs ER export of lysosomal enzymes and lowers lysosomal enzyme levels. The downstream connection from that trafficking defect to ceroid storage remains unresolved.

CLN6 hgnc:2077

endoplasmic reticulum to Golgi vesicle-mediated transport GO:0006888 ↕ DYSREGULATED lysosome organization GO:0007040 ↕ DYSREGULATED

endoplasmic reticulum GO:0005783 Golgi apparatus GO:0005794 lysosome GO:0005764

Downstream

Lipopigment Accumulation in Lysosomes Impaired CLN6/EGRESS-mediated ER export diminishes lysosomal enzyme delivery and may contribute to storage pathology, but the transition to ceroid accumulation is not established by the cited experiments.

Show evidence (3 references)

PMID:30561534 SUPPORT Human Clinical

"Mutation of CLN6 has emerged as the most important cause of recessive Kufs disease but, remarkably, is also responsible for variant late infantile ceroid lipofuscinosis."

Human clinical data anchor CLN6 pathogenic variants as a major cause of recessive Kufs disease.

PMID:32597833 SUPPORT In Vitro

"Experiments focused on protein interaction and trafficking identified CLN6 as an obligate component of a CLN6-CLN8 complex (herein referred to as EGRESS: ER-to-Golgi relaying of enzymes of the lysosomal system), which recruits lysosomal enzymes at the ER to promote their Golgi transfer."

Protein-interaction and trafficking experiments support CLN6 as an obligate component of the ER-to-Golgi lysosomal-enzyme relay.

PMID:32597833 SUPPORT Model Organism

"Mice lacking both CLN6 and CLN8 did not display aggravated pathology compared with the single deficiencies, indicating that the EGRESS complex works as a functional unit."

Mouse knockout evidence supports CLN6 and CLN8 functioning in the same EGRESS pathway in vivo.

Lipopigment Accumulation in Lysosomes

Adult NCL neurons accumulate autofluorescent ceroid lipopigment in lysosomal storage bodies. This is the defining pathological hallmark of Kufs disease and the broader NCL group.

neuron CL:0000540

lysosomal transport GO:0007041 ↕ DYSREGULATED

lysosome GO:0005764

Downstream

Autofluorescent ceroid lipopigment storage Adult NCL lysosomal storage is directly observable as autofluorescent ceroid/lipopigment storage material in neural tissue.

Progressive Neurodegeneration Lysosomal lipopigment storage contributes to the progressive neurodegeneration that drives the clinical phenotype of adult NCL.

Show evidence (3 references)

PMID:21820099 SUPPORT Human Clinical

"Autosomal-dominant adult-onset neuronal ceroid lipofuscinosis (ANCL) is characterized by accumulation of autofluorescent storage material in neural tissues and neurodegeneration"

Direct evidence that ANCL is defined by autofluorescent lysosomal storage in neural tissues.

PMID:30561534 SUPPORT Human Clinical

"Ultrastructural examination of the pathology revealed fingerprint profiles as the characteristic inclusions, but they were not reliably seen in tissues other than brain."

Human CLN6-related Kufs disease shows characteristic ultrastructural storage inclusions in brain.

PMID:23838030 SUPPORT Other

"The neuronal ceroid lipofuscinoses represent a group of disorders characterized by neurodegeneration and intracellular accumulation of an auto-fluorescent lipopigment."

The classification review supports lipopigment accumulation as a shared defining feature across the NCL group.

DNAJC5/CSPalpha Palmitoylation-Dependent Sorting Defect

In autosomal dominant CLN4 (Parry disease), pathogenic variants in DNAJC5 encoding cysteine-string protein alpha (CSPalpha) impair palmitoylation-dependent sorting. The initially reported substitution and deletion and a later cysteine-string-domain duplication all produce this cellular-localization defect.

neuron CL:0000540

DNAJC5 hgnc:16235

protein palmitoylation GO:0018345 ↕ DYSREGULATED protein localization to membrane GO:0072657 ↕ DYSREGULATED

Downstream

DNAJC5 Microautophagy-MAPS Imbalance CLN4-associated DNAJC5 variants produce both abnormal palmitoylation-dependent sorting and uncoupling of microautophagy from MAPS, but the cited experiments do not isolate sorting failure as the direct cause of the protein-quality-control imbalance.

Show evidence (2 references)

PMID:21820099 SUPPORT In Vitro

"These mutations-causing a deletion, p.Leu116del, and an amino acid exchange, p.Leu115Arg, respectively-are located within the cysteine-string domain of the protein and affect both palmitoylation-dependent sorting and the amount of CSPα in neuronal cells."

Cultured-neuron experiments directly support abnormal sorting of the two initially described CSPalpha variants.

PMID:31919451 SUPPORT In Vitro

"This variant leads to a duplication of the central core motif of the cysteine-string domain of CSPα and affects palmitoylation-dependent CSPα sorting in cultured neuronal cells similarly to two previously described CSPα variants, p.(Leu115Arg) and p.(Leu116del)."

Cultured neuronal cells show the same sorting defect for the later in-frame duplication.

DNAJC5/CSPalpha Functional Depletion and Presynaptic Dysfunction

The original CLN4 study proposed that depletion of functional CSPalpha contributes to presynaptic dysfunction and progressive neurodegeneration. Because the source uses the hedged phrase "might cause," this is retained as an atomic emerging mechanism rather than asserted as a demonstrated causal chain.

neuron CL:0000540

DNAJC5 hgnc:16235

Downstream

Progressive Neurodegeneration Functional CSPalpha depletion is proposed to contribute to progressive neurodegeneration through presynaptic dysfunction.

Show evidence (1 reference)

PMID:21820099 SUPPORT Other

"The resulting depletion of functional CSPα might cause in parallel the presynaptic dysfunction and the progressive neurodegeneration observed in affected individuals"

The authors propose, rather than directly demonstrate, the presynaptic arm of the CLN4 mechanism.

DNAJC5 Microautophagy-MAPS Imbalance

DNAJC5 has coupled roles in ESCRT-dependent endosomal microautophagy and misfolding-associated protein secretion (MAPS). CLN4-associated mutants uncouple these protein-quality-control routes, generating DNAJC5-containing autofluorescent storage material in cells and neurodegeneration in a Drosophila model.

neuron CL:0000540

DNAJC5 hgnc:16235

microautophagy GO:0016237 ↕ DYSREGULATED

Downstream

Lipopigment Accumulation in Lysosomes Uncoupling DNAJC5-dependent microautophagy and MAPS generates DNAJC5-containing autofluorescent storage material resembling patient lipofuscin.

Progressive Neurodegeneration The same protein-quality-control imbalance induces neurodegeneration in an in vivo CLN4 model.

Show evidence (1 reference)

PMID:35506243 SUPPORT In Vitro

"Here we report two functionally distinct but coupled chaperoning activities of DNAJC5, which jointly regulate lysosomal homeostasis: While endolysosome-associated DNAJC5 promotes ESCRT-dependent microautophagy, a fraction of perinuclear and non-lysosomal DNAJC5 mediates MAPS."

Cell-based experiments define the coupled DNAJC5 microautophagy and MAPS activities.

Cathepsin F Lysosomal Protease Dysfunction

Recessive missense variants in CTSF are predicted to alter the structure and function of cathepsin F, a lysosomal cysteine protease, providing a plausible mechanism for the storage-disease phenotype across CLN13. A Ctsf knockout mouse recapitulates the light- and electron-microscopic pathology of Kufs disease.

neuron CL:0000540

CTSF hgnc:2531

lysosomal proteolysis GO:0007039 ↕ DYSREGULATED

cysteine-type peptidase activity GO:0008234 ↕ DYSREGULATED

Downstream

Lipopigment Accumulation in Lysosomes Predicted cathepsin F dysfunction is proposed to impair lysosomal proteolysis and drive ceroid lipopigment storage in Type B Kufs disease.

Show evidence (2 references)

PMID:23297359 SUPPORT Other

"CTSF encodes cathepsin F, a lysosomal cysteine protease, dysfunction of which is a highly plausible candidate mechanism for a storage disorder like ceroid lipofuscinosis."

The human genetic study describes the lysosomal-protease mechanism as highly plausible but does not directly measure the full causal chain.

PMID:23297359 SUPPORT Model Organism

"re-examination of a previously published mouse knockout of Ctsf shows that it recapitulates the light and electron-microscopic pathological features of Kufs disease."

Mouse-model recapitulation of Kufs pathology supports the CTSF loss-of-function mechanism.

Progressive Neurodegeneration

Adult NCL produces a progressive neurodegenerative phenotype manifesting as dementia, ataxia, and motor system dysfunction, with or without progressive myoclonus epilepsy depending on subtype.

neuron CL:0000540

Downstream

Dementia Ongoing CLN6-related neurodegeneration produces progressive dementia, which was invariable in the cited CLN6 cohort.

Myoclonus Neurodegeneration is associated with myoclonic seizures in CLN6 Kufs A; the intervening circuit mechanisms are not specified by the cohort.

Cerebellar Ataxia Neurodegeneration produces progressive ataxia, the most prominent motor feature of CLN6-related Kufs disease.

Seizure The progressive myoclonus epilepsy branch of CLN6-related Type A Kufs disease includes tonic-clonic seizures.

Cerebral Atrophy Progressive CLN6 disease and reported CTSF-related CLN13 can be accompanied by cerebral cortical atrophy on MRI.

Cerebellar Atrophy Progressive CLN6 disease and reported CTSF-related CLN13 can be accompanied by cerebellar atrophy on MRI.

Extrapyramidal Motor Dysfunction The phenotype-defined Type B branch includes extrapyramidal motor dysfunction; CTSF explains a minority of molecularly resolved cases.

Tremor CTSF/CLN13 adult NCL can present with cerebellar tremor.

Depression Depression can be present at onset in CTSF/CLN13 adult NCL.

Anxiety Anxiety can be present at onset in CTSF/CLN13 adult NCL.

Show evidence (2 references)

PMID:30561534 SUPPORT Human Clinical

"MRI showed progressive cerebral and cerebellar atrophy."

Imaging evidence for progressive cerebral and cerebellar neurodegeneration in CLN6-related Kufs disease.

PMID:23838030 SUPPORT Other

"The neuronal ceroid lipofuscinoses represent a group of disorders characterized by neurodegeneration and intracellular accumulation of an auto-fluorescent lipopigment."

The classification review supports neurodegeneration as a defining feature shared across adult-NCL branches.

✶

Histopathology

1

Fingerprint Lipopigment Inclusions

The defining ultrastructural pathology of CLN6-related Kufs disease is autofluorescent lipopigment storage with fingerprint inclusion profiles in neurons. Curvilinear profiles, which are characteristic of variant late infantile NCL, are not a feature of CLN6-related Kufs disease. Detection of storage material can be unreliable in tissues other than brain, contributing to diagnostic difficulty.

Show evidence (2 references)

PMID:30561534 SUPPORT Human Clinical

"Ultrastructural examination of the pathology revealed fingerprint profiles as the characteristic inclusions, but they were not reliably seen in tissues other than brain."

Direct evidence that fingerprint profiles are the characteristic ultrastructural inclusions of CLN6-related Kufs disease.

PMID:30561534 SUPPORT Human Clinical

"Curvilinear profiles, which are seen in the late infantile form, were not a feature."

Distinguishes adult Kufs ultrastructural pathology from the curvilinear inclusions of late-infantile NCL.

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Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.

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Phenotypes

11

Nervous System 9

Dementia HP:0000726

Course: PROGRESSIVE

Show evidence (3 references)

PMID:30561534 SUPPORT Human Clinical

"Dementia appeared to be an invariable accompaniment, although it could take a number of years to manifest and occasionally cognitive impairment preceded myoclonic seizures."

Berkovic et al. document dementia as an invariable feature of CLN6-related Kufs disease.

PMID:23838030 SUPPORT Other

"Clinical features include ataxia, progressive dementia, seizures, and myoclonus."

The classification review documents progressive dementia in DNAJC5-related CLN4.

PMID:35359645 SUPPORT Other

"2nd-7th Seizures, myoclonus, cerebellar tremor, cognitive decline, depression, anxiety"

The adult-NCL table documents cognitive decline in CTSF/CLN13 disease.

Myoclonus HP:0001336

Show evidence (3 references)

PMID:30561534 SUPPORT Human Clinical

"The typical presentation was of progressive myoclonus epilepsy with debilitating myoclonic seizures and relatively infrequent tonic-clonic seizures."

Directly identifies debilitating myoclonic seizures as the typical presentation of Type A Kufs disease.

PMID:35359645 SUPPORT Other

"2nd-7th Seizures, myoclonus, cerebellar tremor, cognitive decline, depression, anxiety"

The adult-NCL table lists myoclonus at onset in CTSF/CLN13 disease.

PMID:35359645 SUPPORT Other

"3rd-5th Seizures, action myoclonus, visual failure"

The adult-NCL table lists action myoclonus at onset in DNAJC5/CLN4.

Seizure HP:0001250

Show evidence (3 references)

PMID:30561534 SUPPORT Human Clinical

"The typical presentation was of progressive myoclonus epilepsy with debilitating myoclonic seizures and relatively infrequent tonic-clonic seizures."

Supports tonic-clonic seizures as a clinical feature of Type A Kufs disease.

PMID:35359645 SUPPORT Other

"2nd-7th Seizures, myoclonus, cerebellar tremor, cognitive decline, depression, anxiety"

The adult-NCL table lists seizures at onset in CTSF/CLN13 disease.

PMID:35359645 SUPPORT Other

"3rd-5th Seizures, action myoclonus, visual failure"

The adult-NCL table lists seizures at onset in DNAJC5/CLN4.

Cerebellar Ataxia Progressive cerebellar ataxia HP:0002073

Show evidence (2 references)

PMID:30561534 SUPPORT Human Clinical

"Ataxia was the most prominent motor feature."

Supports ataxia as the most prominent motor feature in CLN6-related Kufs disease.

PMID:23838030 SUPPORT Other

"Clinical features include ataxia, progressive dementia, seizures, and myoclonus."

The classification review documents ataxia in DNAJC5-related CLN4.

Cerebral Atrophy Cerebral cortical atrophy HP:0002120

Course: PROGRESSIVE

Show evidence (2 references)

PMID:30561534 SUPPORT Human Clinical

"MRI showed progressive cerebral and cerebellar atrophy."

Direct neuroimaging evidence of progressive cerebral atrophy in CLN6-related Kufs disease.

PMID:39720560 SUPPORT Human Clinical

"Clinical radiologic scans revealed bilateral cortical atrophy, ventriculomegaly, a thin corpus callosum, and cerebellar vermian atrophy."

The CLN13 index case adds direct MRI evidence of bilateral cortical atrophy without implying frequency.

Cerebellar Atrophy HP:0001272

Course: PROGRESSIVE

Show evidence (2 references)

PMID:30561534 SUPPORT Human Clinical

"MRI showed progressive cerebral and cerebellar atrophy."

Directly documents progressive cerebellar atrophy in the CLN6 cohort.

PMID:39720560 SUPPORT Human Clinical

"Clinical radiologic scans revealed bilateral cortical atrophy, ventriculomegaly, a thin corpus callosum, and cerebellar vermian atrophy."

The CLN13 index case adds direct MRI evidence of cerebellar vermian atrophy without implying frequency.

Tremor HP:0001337

Show evidence (1 reference)

PMID:35359645 SUPPORT Other

"2nd-7th Seizures, myoclonus, cerebellar tremor, cognitive decline, depression, anxiety"

The adult-NCL classification table lists cerebellar tremor for CTSF/CLN13.

Depression HP:0000716

Show evidence (1 reference)

PMID:35359645 SUPPORT Other

"2nd-7th Seizures, myoclonus, cerebellar tremor, cognitive decline, depression, anxiety"

The adult-NCL classification table lists depression for CTSF/CLN13.

Anxiety HP:0000739

Show evidence (1 reference)

PMID:35359645 SUPPORT Other

"2nd-7th Seizures, myoclonus, cerebellar tremor, cognitive decline, depression, anxiety"

The adult-NCL classification table lists anxiety for CTSF/CLN13.

Other 2

EEG photosensitivity EEG with photoparoxysmal response HP:0010852

Show evidence (1 reference)

PMID:30561534 SUPPORT Human Clinical

"Patients were usually highly photosensitive on EEG."

Documents high EEG photosensitivity as a characteristic feature of CLN6-related Kufs disease.

Extrapyramidal Motor Dysfunction Abnormality of extrapyramidal motor function HP:0002071

Show evidence (1 reference)

PMID:23838030 SUPPORT Other

"Type B is characterized by dementia with cerebellar and/or extrapyramidal motor symptoms."

Supports the legacy Type B phenotype; CTSF-specific penetrance is not established by this review.

🧬

Genetic Associations

3

CLN6 (Pathogenic Variants)

Gene: CLN6 hgnc:2077

Show evidence (2 references)

PMID:21549341 SUPPORT Human Clinical

"Mutations in CLN6 are the major cause of recessive Kufs type A disease."

Direct evidence identifying CLN6 as the major recessive cause of Kufs Type A disease.

PMID:30561534 SUPPORT Human Clinical

"Mutation of CLN6 has emerged as the most important cause of recessive Kufs disease but, remarkably, is also responsible for variant late infantile ceroid lipofuscinosis."

Confirms CLN6 as the most important recessive cause of Kufs disease and notes the contrasting variant late-infantile NCL phenotype caused by the same gene.

CTSF (Pathogenic Variants)

Gene: CTSF hgnc:2531

Show evidence (4 references)

PMID:23297359 SUPPORT Human Clinical

"Exome sequencing of five samples from the two families identified homozygous and compound heterozygous missense mutations in CTSF within this linkage region."

Identifies recessive CTSF missense mutations as the cause of Type B Kufs disease.

PMID:23297359 SUPPORT Other

"CTSF encodes cathepsin F, a lysosomal cysteine protease, dysfunction of which is a highly plausible candidate mechanism for a storage disorder like ceroid lipofuscinosis."

The authors propose a plausible lysosomal-protease mechanism but do not directly test the full causal chain.

PMID:23297359 SUPPORT Human Clinical

"Although CTSF mutations account for a minority of cases of type B Kufs"

Qualifies the CTSF association so it is not presented as the usual or exhaustive Type B cause.

+ 1 more reference

DNAJC5 (Pathogenic Variants)

Gene: DNAJC5 hgnc:16235

Show evidence (3 references)

PMID:21820099 SUPPORT Human Clinical

"we identified in five individuals one of two disease-causing mutations, c.346_348delCTC and c.344T>G, in DNAJC5 encoding cysteine-string protein alpha (CSPα)."

Identifies the two recurrent DNAJC5 disease-causing mutations in autosomal dominant adult NCL.

PMID:21820099 SUPPORT In Vitro

"These mutations-causing a deletion, p.Leu116del, and an amino acid exchange, p.Leu115Arg, respectively-are located within the cysteine-string domain of the protein and affect both palmitoylation-dependent sorting and the amount of CSPα in neuronal cells."

Supports both the protein-level consequences and the localization of DNAJC5 variants to the cysteine-string domain.

PMID:31919451 SUPPORT Human Clinical

"Here we report one family with autosomal dominant (AD) Kufs disease caused by a 30 bp in-frame duplication in DNAJC5, encoding the cysteine-string protein alpha (CSPα)."

A later family study expands the pathogenic DNAJC5 variant spectrum beyond the two initially reported alleles.

💊

Medical Actions

2

Supportive Care

Action: Supportive Care NCIT:C15747

Adult NCL management is palliative and symptomatic. This entry does not infer supportive-care efficacy from a failed disease-directed treatment case and does not represent supportive care as disease-modifying.

Show evidence (1 reference)

PMID:35359645 SUPPORT Other

"palliative care and symptomatic treatments which are still the main therapeutic interventions."

The NCL clinical review directly supports palliative and symptomatic management without claiming a disease-modifying effect.

Antiseizure Pharmacotherapy

Action: Pharmacotherapy NCIT:C15986

Agent: anticonvulsant agent NCIT:C264

Antiseizure medications are used symptomatically to reduce seizure burden in NCL, including seizure-bearing adult branches. They are not represented as disease-modifying or as reliably producing complete seizure freedom.

Target Phenotypes: Seizure HP:0001250

Show evidence (1 reference)

PMID:35359645 SUPPORT Other

"there is consensus that medications for epilepsy are used to alleviate seizure burden"

Expert clinical review supports antiseizure medication as symptomatic burden reduction rather than proof of disease modification.

🔬

Biochemical Markers

4

Autofluorescent ceroid lipopigment storage (INCREASED)

Context: Adult NCL is defined pathologically by autofluorescent ceroid/lipopigment storage material in neural tissue. No specific local CHEBI or NCIT term was found for ceroid or lipofuscin, so this readout is represented without a forced biomarker term.

Pathograph Readouts

Readout Of Lipopigment Accumulation in Lysosomes Positive Diagnostic

Increased autofluorescent storage material reports the core lysosomal lipopigment accumulation node.

Show evidence (1 reference)

PMID:21820099 SUPPORT Human Clinical

"Autosomal-dominant adult-onset neuronal ceroid lipofuscinosis (ANCL) is characterized by accumulation of autofluorescent storage material in neural tissues and neurodegeneration"

Direct human evidence defines ANCL by autofluorescent storage material in neural tissue.

Show evidence (2 references)

PMID:21820099 SUPPORT Human Clinical

"Autosomal-dominant adult-onset neuronal ceroid lipofuscinosis (ANCL) is characterized by accumulation of autofluorescent storage material in neural tissues and neurodegeneration"

Supports autofluorescent neural storage material as the defining adult NCL biochemical/pathologic readout.

PMID:23838030 SUPPORT Other

"The neuronal ceroid lipofuscinoses represent a group of disorders characterized by neurodegeneration and intracellular accumulation of an auto-fluorescent lipopigment."

The classification review supports autofluorescent lipopigment accumulation as a shared NCL readout.

Proteolysis-resistant ceroid deposits (INCREASED)

Context: In DNAJC5-related autosomal dominant adult NCL (CLN4), depletion of functional CSPalpha is linked to lysosomal accumulation of misfolded, proteolysis-resistant proteins that form characteristic ceroid deposits; this readout is specific to the proposed DNAJC5/CLN4 mechanism rather than a marker for every adult-NCL branch.

Pathograph Readouts

Readout Of DNAJC5 Microautophagy-MAPS Imbalance Positive

Proteolysis-resistant neuronal ceroid deposits report the lysosomal protein-quality-control consequence of DNAJC5/CSPalpha dysfunction.

Show evidence (1 reference)

PMID:21820099 SUPPORT Other

"lysosomal accumulation of misfolded and proteolysis-resistant proteins in the form of characteristic ceroid deposits in neurons."

The original paper proposes this deposit as one arm of the CSPalpha mechanism; it does not validate it as a diagnostic assay.

Readout Of Lipopigment Accumulation in Lysosomes Positive

These deposits are a DNAJC5-related manifestation of the broader adult NCL lysosomal lipopigment storage node.

Show evidence (1 reference)

PMID:21820099 SUPPORT Other

"lysosomal accumulation of misfolded and proteolysis-resistant proteins in the form of characteristic ceroid deposits in neurons."

The proposed mechanism localizes the deposits to lysosomes but does not establish a validated clinical readout.

Show evidence (1 reference)

PMID:21820099 SUPPORT Other

"lysosomal accumulation of misfolded and proteolysis-resistant proteins in the form of characteristic ceroid deposits in neurons."

Supports the authors' proposed proteolysis-resistant deposit mechanism in DNAJC5-related adult NCL.

Cathepsin F lysosomal cysteine protease dysfunction (DYSREGULATED)

Context: The CTSF discovery study identifies cathepsin F as a lysosomal cysteine protease and describes its dysfunction as a highly plausible storage mechanism. It does not directly quantify enzyme activity in patients, so this is modeled as dysregulated rather than a measured diagnostic decrease.

Pathograph Readouts

Readout Of Cathepsin F Lysosomal Protease Dysfunction Present Absent

Presence of inferred cathepsin F dysfunction reports the CTSF-driven lysosomal proteolysis defect; no measured clinical assay is asserted.

Show evidence (1 reference)

PMID:23297359 SUPPORT Other

"CTSF encodes cathepsin F, a lysosomal cysteine protease, dysfunction of which is a highly plausible candidate mechanism for a storage disorder like ceroid lipofuscinosis."

The paper explicitly calls this mechanism highly plausible rather than reporting a direct patient enzyme-activity measurement.

Show evidence (1 reference)

PMID:23297359 SUPPORT Other

"CTSF encodes cathepsin F, a lysosomal cysteine protease, dysfunction of which is a highly plausible candidate mechanism for a storage disorder like ceroid lipofuscinosis."

Supports inferred cathepsin F dysfunction without overclaiming a measured decrease or diagnostic endpoint.

Lysosomal enzyme levels at the lysosome (DECREASED)

Context: In CLN6-deficient experimental systems, inefficient ER export of lysosomal enzymes leads to reduced lysosomal enzyme levels, a cellular biochemical readout of the CLN6/EGRESS trafficking defect.

Pathograph Readouts

Readout Of CLN6 EGRESS Complex Lysosomal Enzyme Trafficking Defect Negative

Lower lysosomal enzyme levels report impaired CLN6-dependent ER-to-Golgi lysosomal-enzyme transfer.

Show evidence (2 references)

PMID:32597833 SUPPORT In Vitro

"In vitro and in vivo studies showed that CLN6 deficiency results in inefficient ER export of lysosomal enzymes and diminished levels of the enzymes at the lysosome."

The in vitro component supports reduced lysosomal enzyme levels as a cellular readout of CLN6 deficiency.

PMID:32597833 SUPPORT Model Organism

"In vitro and in vivo studies showed that CLN6 deficiency results in inefficient ER export of lysosomal enzymes and diminished levels of the enzymes at the lysosome."

The in vivo component supports reduced lysosomal enzyme levels as a model-organism readout of CLN6 deficiency.

Show evidence (2 references)

PMID:32597833 SUPPORT In Vitro

"In vitro and in vivo studies showed that CLN6 deficiency results in inefficient ER export of lysosomal enzymes and diminished levels of the enzymes at the lysosome."

The in vitro component supports reduced lysosomal enzyme levels as a biochemical/cellular consequence of CLN6 deficiency.

PMID:32597833 SUPPORT Model Organism

"In vitro and in vivo studies showed that CLN6 deficiency results in inefficient ER export of lysosomal enzymes and diminished levels of the enzymes at the lysosome."

The in vivo component supports reduced lysosomal enzyme levels in a CLN6-deficient model context.

🔬

Diagnosis

3

Genetic diagnosis

Diagnosis was traditionally dependent on demonstration of characteristic storage material via brain biopsy or autopsy. For the three classic adult branches modeled here, gene-first testing of CLN6, CTSF, and DNAJC5 can establish a molecular diagnosis and largely supersede invasive biopsy; broader adult-NCL presentations require an appropriately broad NCL panel.

Show evidence (2 references)

PMID:30561534 SUPPORT Human Clinical

"The diagnosis of Kufs remains challenging but, with the availability of genetic diagnosis, this will largely supersede the use of diagnostic biopsies, particularly as biopsies of peripheral tissues has unsatisfactory sensitivity and specificity."

Supports genetic testing as the preferred diagnostic strategy in suspected Kufs disease.

PMID:21549341 SUPPORT Human Clinical

"Sequencing of CLN6 will provide a simple diagnostic strategy in this disorder, in which definitive identification usually requires invasive biopsy."

Arsov et al. propose CLN6 sequencing as a simple diagnostic strategy that can replace invasive biopsy.

DNAJC5 insertion and duplication analysis

In unsolved autosomal dominant adult NCL, analysis should account for insertions or duplications in the DNAJC5 cysteine-string domain. A 30-bp duplication was initially missed by both standard Sanger sequencing and WES, so a negative routine result does not exclude this variant class.

Show evidence (2 references)

PMID:31919451 SUPPORT Human Clinical

"It was also missed by subsequent whole-exome sequencing (WES)."

The family study documents a clinically important false-negative limitation of routine DNAJC5 testing.

PMID:31919451 SUPPORT Human Clinical

"Independently occurring variants in the genomic sequence of DNAJC5 encoding the cysteine-string domain of CSPα suggest that this region may be more prone to DNA replication errors and that insertions or duplications within this domain should be considered in unsolved ANCL cases."

The authors explicitly recommend considering this variant class in unsolved adult NCL.

Differential diagnosis and diagnostic delay

Adult NCL can be mistaken for acquired neurologic disorders when refractory epilepsy, cognitive decline, movement abnormalities, and progressive brain atrophy evolve over years. Early inclusion of adult NCL in the differential diagnosis may prevent ineffective immunotherapy or shunt procedures.

Show evidence (2 references)

PMID:39470529 SUPPORT Human Clinical

"Initially diagnosed with autoimmune encephalitis, the patient was later diagnosed with normal-pressure hydrocephalus. A definitive diagnosis of adult-onset neuronal ceroid lipofuscinosis (ANCL) was established after 10 years of observation, utilizing biopsy and genetic testing."

The case directly documents two misdiagnoses and a ten-year delay before definitive adult-NCL diagnosis.

PMID:39470529 SUPPORT Human Clinical

"Improved understanding of ANCL from both clinical and radiological perspectives, coupled with early consideration of differential diagnoses, could minimize unnecessary interventions and optimize patient care."

The authors explicitly connect earlier differential consideration with avoiding unnecessary interventions.

🩻

Imaging Findings

4

Cerebral Atrophy on MRI in CLN6

Structural MRI shows progressive cerebral atrophy in CLN6 Kufs A.

Mri CLN6 Kufs A

Cerebral cortical atrophy HP:0002120 cerebral cortex UBERON:0000956 Cerebral cortical atrophy HP:0002120

Show evidence (1 reference)

PMID:30561534 SUPPORT Human Clinical

"MRI showed progressive cerebral and cerebellar atrophy."

Directly documents the structured cerebral MRI finding.

Cerebral Atrophy on MRI in CLN13

Bilateral cortical atrophy was documented in a molecularly confirmed CLN13 index case.

Mri CTSF CLN13

Cerebral cortical atrophy HP:0002120 cerebral cortex UBERON:0000956 Cerebral cortical atrophy HP:0002120

Show evidence (1 reference)

PMID:39720560 SUPPORT Human Clinical

"Clinical radiologic scans revealed bilateral cortical atrophy, ventriculomegaly, a thin corpus callosum, and cerebellar vermian atrophy."

Directly documents bilateral cortical atrophy in a molecularly confirmed CLN13 case without implying population frequency.

Cerebellar Atrophy on MRI in CLN6

Structural MRI shows progressive cerebellar atrophy in CLN6 Kufs A.

Mri CLN6 Kufs A

Cerebellar atrophy HP:0001272 cerebellum UBERON:0002037 Cerebellar atrophy HP:0001272

Show evidence (1 reference)

PMID:30561534 SUPPORT Human Clinical

"MRI showed progressive cerebral and cerebellar atrophy."

Directly documents the structured cerebellar MRI finding.

Cerebellar Atrophy on MRI in CLN13

Cerebellar vermian atrophy was documented in a molecularly confirmed CLN13 index case.

Mri CTSF CLN13

Cerebellar atrophy HP:0001272 cerebellum UBERON:0002037 Cerebellar atrophy HP:0001272

Show evidence (1 reference)

PMID:39720560 SUPPORT Human Clinical

"Clinical radiologic scans revealed bilateral cortical atrophy, ventriculomegaly, a thin corpus callosum, and cerebellar vermian atrophy."

Directly documents cerebellar vermian atrophy in a molecularly confirmed CLN13 case without implying population frequency.

📈

Progression

4

Adult onset

CLN6 Kufs A Age: 12–51 years

CLN6-related Kufs A typically begins in the third or fourth decade of life, with a bimodal teenage/early adult onset distribution.

Show evidence (1 reference)

PMID:30561534 SUPPORT Human Clinical

"Mean age of onset was 28 years (range 12-51) with bimodal peaks in teenage and early adult life."

Berkovic et al. summarize the typical age-at-onset distribution in CLN6-related Kufs disease.

Progressive disability

CLN6 Kufs A Age: Adulthood

Patients with CLN6-related Kufs disease progressively lose independent ambulation and become wheelchair-bound a mean of 12 years post-onset, with median survival of 26 years.

Show evidence (2 references)

PMID:30561534 SUPPORT Human Clinical

"Patients became wheelchair-bound with a mean 12 years post-onset."

Direct evidence for the progressive disability course in CLN6-related Kufs disease.

PMID:30561534 SUPPORT Human Clinical

"The median survival time was 26 years from disease onset."

Supports a progressive but prolonged disease course relative to childhood NCL.

CTSF CLN13 onset

CTSF CLN13 Age: Second to seventh decade

The reported CTSF/CLN13 adult-onset range is broad. Presentations span classic and nonclassic Kufs syndromes, isolated dementia, movement disorders, seizures, myoclonus, and psychiatric manifestations.

Show evidence (2 references)

PMID:35359645 SUPPORT Other

"KD-B/CLN13 #615362 AR 11q13.2 CLN13/CTSF CTSF (soluble protein): lysosomal enzyme 2nd-7th Seizures, myoclonus, cerebellar tremor, cognitive decline, depression, anxiety"

The adult-NCL classification table reports the CTSF/CLN13 onset range and presenting features.

PMID:39720560 SUPPORT Human Clinical

"A review of 20 reported CLN13 patients revealed novel clinical subtypes, including KSB type I (KSB-I), KSB type II (KSB-II), and Kufs syndrome C (KSC)."

A systematic review of 20 reported patients establishes the breadth of the CLN13 clinical spectrum.

DNAJC5 CLN4 onset

DNAJC5 CLN4 Age: Third to fifth decade

DNAJC5-related CLN4 (Parry disease) is an adult-onset dominant branch with seizures and action myoclonus among its presenting manifestations. Retinal degeneration and visual loss are not regarded as characteristic CLN4 features; the visual-failure phrase in the cited table is not promoted to a phenotype assertion.

Show evidence (1 reference)

PMID:35359645 SUPPORT Other

"Parry/CLN4 #162350 AD 20q13.33 CLN4/DNAJC5 CSPα (soluble protein): cytosol (vesicular membrane) 3rd-5th Seizures, action myoclonus, visual failure"

The adult-NCL classification table reports onset in the third to fifth decades for DNAJC5/CLN4.

{ }

Source YAML

click to show

name: Adult Neuronal Ceroid Lipofuscinosis
category: Mendelian
creation_date: '2026-05-13T12:00:00Z'
description: >
  Adult neuronal ceroid lipofuscinosis (adult NCL) is the adult-onset umbrella
  within the neuronal ceroid lipofuscinoses, a genetically heterogeneous group
  of lysosomal-storage neurodegenerative diseases. This entry models the three
  best-defined classic adult branches using gene-first names: recessive
  CLN6-related Kufs A, recessive CTSF-related CLN13, and dominant
  DNAJC5-related CLN4 (Parry disease). Rarer adult-onset allelic presentations
  of other NCL genes, including PPT1/CLN1, TPP1/CLN2, CLN5, CTSD/CLN10, and
  GRN/CLN11, remain within the broader adult-NCL concept but are not
  mechanistically expanded here.
  CLN6-related Kufs A presents as progressive myoclonus epilepsy with dementia
  and ataxia; CTSF-related CLN13 spans several dementia, movement-disorder, and
  mixed Kufs phenotypes rather than mapping cleanly to classic Type B; and
  DNAJC5-related CLN4 is kept separate from those recessive branches. Lack of
  visual involvement is characteristic of CLN6-related Kufs A and
  DNAJC5-related CLN4; an isolated review-table entry listing visual failure in
  CLN4 is treated as a classification-table error rather than a positive
  phenotype assertion.
  Pathologically, neurons accumulate autofluorescent ceroid lipopigment; in
  CLN6-related Kufs disease, fingerprint profiles predominate.
  CLN6 participates in an ER-to-Golgi relay for lysosomal enzymes, so
  CLN6-related adult NCL is modeled as a lysosomal-enzyme trafficking defect;
  how that defect connects to ceroid storage remains unresolved.
  Management remains palliative and symptomatic; antiseizure medication is
  used to reduce seizure burden rather than being represented as
  disease-modifying therapy.
disease_term:
  preferred_term: adult neuronal ceroid lipofuscinosis
  term:
    id: MONDO:0019260
    label: adult neuronal ceroid lipofuscinosis
synonyms:
- Kufs disease
- adult-onset neuronal ceroid lipofuscinosis
- ceroid lipofuscinosis, neuronal, adult-onset
- adult NCL
- ANCL
parents:
- Neuronal Ceroid Lipofuscinosis
- Lysosomal Storage Disease
- Neurodegenerative Disease
has_subtypes:
- name: CLN6 Kufs A
  display_name: CLN6-related Kufs disease Type A
  description: >
    The recessive CLN6-related adult branch presents as progressive myoclonus
    epilepsy with debilitating myoclonus, later dementia, and ataxia. It is
    distinguished from dominant DNAJC5-related CLN4 despite overlapping
    myoclonus and seizure phenotypes.
  genes:
  - preferred_term: CLN6
    term:
      id: hgnc:2077
      label: CLN6
  evidence:
  - reference: PMID:21549341
    reference_title: "Kufs disease, the major adult form of neuronal ceroid lipofuscinosis, caused by mutations in CLN6."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Mutations in CLN6 are the major cause of recessive Kufs type A disease."
    explanation: The human family study establishes CLN6 as the major cause of recessive Kufs A.
- name: CTSF CLN13
  display_name: CTSF-related neuronal ceroid lipofuscinosis type 13 (CLN13)
  description: >
    A recessive adult-NCL branch originally discovered in Type B Kufs disease.
    A 2025 systematic review of 20 reported patients found that most did not
    have classic Type B disease and proposed additional Type B and Kufs C
    presentations. CTSF therefore should not be treated either as an exhaustive
    explanation of phenotype-defined Type B Kufs disease or as restricted to
    that phenotype.
  genes:
  - preferred_term: CTSF
    term:
      id: hgnc:2531
      label: CTSF
  evidence:
  - reference: PMID:23297359
    reference_title: "Cathepsin F mutations cause Type B Kufs disease, an adult-onset neuronal ceroid lipofuscinosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Although CTSF mutations account for a minority of cases of type B Kufs, CTSF screening should be considered in cases with early-onset dementia and may avoid the need for invasive biopsies."
    explanation: The discovery cohort establishes CTSF while explicitly limiting it to a minority of Type B cases.
  - reference: PMID:39720560
    reference_title: "Clinical Heterogeneity of Neuronal Ceroid Lipofuscinosis Type 13: A Case Report and Systematic Review of Literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Most patients with CLN13 (14/20) did not present with classic KSB (KSB-I)."
    explanation: The systematic review shows that CTSF-related CLN13 is broader than classic Type B Kufs disease.
- name: DNAJC5 CLN4
  display_name: DNAJC5-related CLN4 (Parry disease)
  description: >
    The autosomal dominant adult-NCL branch caused by DNAJC5 variants. It is
    modeled separately from recessive CLN6 Kufs A and CTSF CLN13 under the
    modern gene-first classification, while retaining Parry disease as its
    clinical eponym.
  genes:
  - preferred_term: DNAJC5
    term:
      id: hgnc:16235
      label: DNAJC5
  evidence:
  - reference: PMID:21820099
    reference_title: "Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "we identified in five individuals one of two disease-causing mutations, c.346_348delCTC and c.344T>G, in DNAJC5 encoding cysteine-string protein alpha (CSPα)."
    explanation: The original human genetic study identifies pathogenic DNAJC5 variants in dominant adult NCL.
  - reference: PMID:23838030
    reference_title: "Classification and natural history of the neuronal ceroid lipofuscinoses."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "There is an autosomal dominant form of neuronal ceroid lipofuscinosis, now classified as CLN4 disease, that is due to mutation in the DNAJC5 gene that codes for a cysteine string protein. This has also been referred to as “Parry disease,” named after the family in which it was first described."
    explanation: A classification review supports the gene-first CLN4 label and Parry eponym.
inheritance:
- name: Autosomal recessive inheritance
  description: >
    The two deeply modeled recessive branches are CLN6-related Kufs A and
    CTSF-related CLN13; CTSF explains only a minority of phenotype-defined
    Type B cases and also causes other adult presentations.
  inheritance_term:
    preferred_term: Autosomal recessive inheritance
    term:
      id: HP:0000007
      label: Autosomal recessive inheritance
  evidence:
  - reference: PMID:21549341
    reference_title: "Kufs disease, the major adult form of neuronal ceroid lipofuscinosis, caused by mutations in CLN6."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We mapped four families with Kufs disease for whom there was good evidence of autosomal-recessive inheritance"
    explanation: >
      The Arsov et al. linkage study establishes autosomal recessive
      inheritance in CLN6-related Kufs disease.
  - reference: PMID:23297359
    reference_title: "Cathepsin F mutations cause Type B Kufs disease, an adult-onset neuronal ceroid lipofuscinosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We performed genome-wide linkage mapping of two families with recessive Type B Kufs disease"
    explanation: Human family linkage establishes recessive inheritance for the CTSF-related CLN13 branch discovered in Type B Kufs families.
- name: Autosomal dominant inheritance
  description: >
    The CLN4 form of adult NCL is caused by autosomal dominant pathogenic
    variants in DNAJC5.
  inheritance_term:
    preferred_term: Autosomal dominant inheritance
    term:
      id: HP:0000006
      label: Autosomal dominant inheritance
  evidence:
  - reference: PMID:21820099
    reference_title: "Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Autosomal-dominant adult-onset neuronal ceroid lipofuscinosis (ANCL) is characterized by accumulation of autofluorescent storage material in neural tissues and neurodegeneration and has an age of onset in the third decade of life or later."
    explanation: >
      Noskova et al. establish DNAJC5/CLN4 as the autosomal dominant adult
      form of NCL.
progression:
- phase: Adult onset
  subtype: CLN6 Kufs A
  age_range: 12–51 years
  notes: >
    CLN6-related Kufs A typically begins in the third or fourth decade of life,
    with a bimodal teenage/early adult onset distribution.
  evidence:
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Mean age of onset was 28 years (range 12-51) with bimodal peaks in teenage and early adult life."
    explanation: >
      Berkovic et al. summarize the typical age-at-onset distribution in
      CLN6-related Kufs disease.
- phase: Progressive disability
  subtype: CLN6 Kufs A
  age_range: Adulthood
  notes: >
    Patients with CLN6-related Kufs disease progressively lose independent
    ambulation and become wheelchair-bound a mean of 12 years post-onset, with
    median survival of 26 years.
  evidence:
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Patients became wheelchair-bound with a mean 12 years post-onset."
    explanation: >
      Direct evidence for the progressive disability course in CLN6-related
      Kufs disease.
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The median survival time was 26 years from disease onset."
    explanation: >
      Supports a progressive but prolonged disease course relative to
      childhood NCL.
- phase: CTSF CLN13 onset
  subtype: CTSF CLN13
  age_range: Second to seventh decade
  notes: >
    The reported CTSF/CLN13 adult-onset range is broad. Presentations span
    classic and nonclassic Kufs syndromes, isolated dementia, movement
    disorders, seizures, myoclonus, and psychiatric manifestations.
  evidence:
  - reference: PMID:35359645
    reference_title: "Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "KD-B/CLN13 #615362 AR 11q13.2 CLN13/CTSF CTSF (soluble protein): lysosomal enzyme 2nd-7th Seizures, myoclonus, cerebellar tremor, cognitive decline, depression, anxiety"
    explanation: The adult-NCL classification table reports the CTSF/CLN13 onset range and presenting features.
  - reference: PMID:39720560
    reference_title: "Clinical Heterogeneity of Neuronal Ceroid Lipofuscinosis Type 13: A Case Report and Systematic Review of Literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A review of 20 reported CLN13 patients revealed novel clinical subtypes, including KSB type I (KSB-I), KSB type II (KSB-II), and Kufs syndrome C (KSC)."
    explanation: A systematic review of 20 reported patients establishes the breadth of the CLN13 clinical spectrum.
- phase: DNAJC5 CLN4 onset
  subtype: DNAJC5 CLN4
  age_range: Third to fifth decade
  notes: >
    DNAJC5-related CLN4 (Parry disease) is an adult-onset dominant branch with
    seizures and action myoclonus among its presenting manifestations. Retinal
    degeneration and visual loss are not regarded as characteristic CLN4
    features; the visual-failure phrase in the cited table is not promoted to a
    phenotype assertion.
  evidence:
  - reference: PMID:35359645
    reference_title: "Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Parry/CLN4 #162350 AD 20q13.33 CLN4/DNAJC5 CSPα (soluble protein): cytosol (vesicular membrane) 3rd-5th Seizures, action myoclonus, visual failure"
    explanation: The adult-NCL classification table reports onset in the third to fifth decades for DNAJC5/CLN4.
genetic:
- name: CLN6
  subtype: CLN6 Kufs A
  association: Pathogenic Variants
  presence: Positive
  gene_term:
    preferred_term: CLN6
    term:
      id: hgnc:2077
      label: CLN6
  notes: >
    Recessive CLN6 pathogenic variants are the most common cause of Kufs
    Type A disease, manifesting as adult-onset progressive myoclonus
    epilepsy with dementia and ataxia, in contrast to the variant
    late-infantile NCL phenotype also caused by CLN6.
  evidence:
  - reference: PMID:21549341
    reference_title: "Kufs disease, the major adult form of neuronal ceroid lipofuscinosis, caused by mutations in CLN6."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Mutations in CLN6 are the major cause of recessive Kufs type A disease."
    explanation: >
      Direct evidence identifying CLN6 as the major recessive cause of
      Kufs Type A disease.
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Mutation of CLN6 has emerged as the most important cause of recessive Kufs disease but, remarkably, is also responsible for variant late infantile ceroid lipofuscinosis."
    explanation: >
      Confirms CLN6 as the most important recessive cause of Kufs disease
      and notes the contrasting variant late-infantile NCL phenotype caused
      by the same gene.
- name: CTSF
  subtype: CTSF CLN13
  association: Pathogenic Variants
  presence: Positive
  gene_term:
    preferred_term: CTSF
    term:
      id: hgnc:2531
      label: CTSF
  notes: >
    Recessive CTSF pathogenic variants cause CLN13. They explain only a
    minority of phenotype-defined Type B Kufs disease, and the molecular
    CLN13 spectrum also includes nonclassic Type B, mixed Kufs,
    movement-disorder, and dementia presentations. CTSF encodes the lysosomal
    cysteine protease cathepsin F.
  evidence:
  - reference: PMID:23297359
    reference_title: "Cathepsin F mutations cause Type B Kufs disease, an adult-onset neuronal ceroid lipofuscinosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Exome sequencing of five samples from the two families identified homozygous and compound heterozygous missense mutations in CTSF within this linkage region."
    explanation: >
      Identifies recessive CTSF missense mutations as the cause of Type B
      Kufs disease.
  - reference: PMID:23297359
    reference_title: "Cathepsin F mutations cause Type B Kufs disease, an adult-onset neuronal ceroid lipofuscinosis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "CTSF encodes cathepsin F, a lysosomal cysteine protease, dysfunction of which is a highly plausible candidate mechanism for a storage disorder like ceroid lipofuscinosis."
    explanation: >
      The authors propose a plausible lysosomal-protease mechanism but do not
      directly test the full causal chain.
  - reference: PMID:23297359
    reference_title: "Cathepsin F mutations cause Type B Kufs disease, an adult-onset neuronal ceroid lipofuscinosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Although CTSF mutations account for a minority of cases of type B Kufs"
    explanation: Qualifies the CTSF association so it is not presented as the usual or exhaustive Type B cause.
  - reference: PMID:39720560
    reference_title: "Clinical Heterogeneity of Neuronal Ceroid Lipofuscinosis Type 13: A Case Report and Systematic Review of Literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Our results expand the CLN13 clinical spectrum and emphasize the importance of screening CTSF variants in clinical dementia and movement disorder cohorts."
    explanation: The systematic review broadens CTSF-related CLN13 beyond the original classic Type B framing.
- name: DNAJC5
  subtype: DNAJC5 CLN4
  association: Pathogenic Variants
  presence: Positive
  gene_term:
    preferred_term: DNAJC5
    term:
      id: hgnc:16235
      label: DNAJC5
  notes: >
    Heterozygous pathogenic variants in DNAJC5 (encoding cysteine-string
    protein alpha, CSPalpha) cause autosomal dominant adult NCL (CLN4/Parry
    disease). The initially reported p.Leu116del and p.Leu115Arg alleles and a
    subsequently identified 30-bp in-frame duplication all alter the
    cysteine-string domain. Insertions and duplications in this region merit
    targeted consideration because standard Sanger sequencing and WES missed
    the duplication through allelic dropout/read-alignment limitations.
  evidence:
  - reference: PMID:21820099
    reference_title: "Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "we identified in five individuals one of two disease-causing mutations, c.346_348delCTC and c.344T>G, in DNAJC5 encoding cysteine-string protein alpha (CSPα)."
    explanation: >
      Identifies the two recurrent DNAJC5 disease-causing mutations in
      autosomal dominant adult NCL.
  - reference: PMID:21820099
    reference_title: "Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "These mutations-causing a deletion, p.Leu116del, and an amino acid exchange, p.Leu115Arg, respectively-are located within the cysteine-string domain of the protein and affect both palmitoylation-dependent sorting and the amount of CSPα in neuronal cells."
    explanation: >
      Supports both the protein-level consequences and the localization of
      DNAJC5 variants to the cysteine-string domain.
  - reference: PMID:31919451
    reference_title: "Autosomal-dominant adult neuronal ceroid lipofuscinosis caused by duplication in DNAJC5 initially missed by Sanger and whole-exome sequencing."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Here we report one family with autosomal dominant (AD) Kufs disease caused by a 30 bp in-frame duplication in DNAJC5, encoding the cysteine-string protein alpha (CSPα)."
    explanation: A later family study expands the pathogenic DNAJC5 variant spectrum beyond the two initially reported alleles.
pathophysiology:
- name: CLN6 EGRESS Complex Lysosomal Enzyme Trafficking Defect
  biological_scale: CELLULAR
  subtypes:
  - CLN6 Kufs A
  description: >
    CLN6 is an endoplasmic-reticulum-associated component of the CLN6-CLN8
    EGRESS complex that recruits lysosomal enzymes at the ER and promotes their
    Golgi transfer. CLN6 deficiency impairs ER export of lysosomal enzymes and
    lowers lysosomal enzyme levels. The downstream connection from that
    trafficking defect to ceroid storage remains unresolved.
  genes:
  - preferred_term: CLN6
    term:
      id: hgnc:2077
      label: CLN6
  biological_processes:
  - preferred_term: endoplasmic reticulum to Golgi vesicle-mediated transport
    modifier: DYSREGULATED
    term:
      id: GO:0006888
      label: endoplasmic reticulum to Golgi vesicle-mediated transport
  - preferred_term: lysosome organization
    modifier: DYSREGULATED
    term:
      id: GO:0007040
      label: lysosome organization
  cellular_components:
  - preferred_term: endoplasmic reticulum
    term:
      id: GO:0005783
      label: endoplasmic reticulum
  - preferred_term: Golgi apparatus
    term:
      id: GO:0005794
      label: Golgi apparatus
  - preferred_term: lysosome
    term:
      id: GO:0005764
      label: lysosome
  evidence:
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Mutation of CLN6 has emerged as the most important cause of recessive Kufs disease but, remarkably, is also responsible for variant late infantile ceroid lipofuscinosis."
    explanation: >
      Human clinical data anchor CLN6 pathogenic variants as a major cause of
      recessive Kufs disease.
  - reference: PMID:32597833
    reference_title: "A CLN6-CLN8 complex recruits lysosomal enzymes at the ER for Golgi transfer."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Experiments focused on protein interaction and trafficking identified CLN6 as an obligate component of a CLN6-CLN8 complex (herein referred to as EGRESS: ER-to-Golgi relaying of enzymes of the lysosomal system), which recruits lysosomal enzymes at the ER to promote their Golgi transfer."
    explanation: >
      Protein-interaction and trafficking experiments support CLN6 as an
      obligate component of the ER-to-Golgi lysosomal-enzyme relay.
  - reference: PMID:32597833
    reference_title: "A CLN6-CLN8 complex recruits lysosomal enzymes at the ER for Golgi transfer."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Mice lacking both CLN6 and CLN8 did not display aggravated pathology compared with the single deficiencies, indicating that the EGRESS complex works as a functional unit."
    explanation: >
      Mouse knockout evidence supports CLN6 and CLN8 functioning in the same
      EGRESS pathway in vivo.
  downstream:
  - target: Lipopigment Accumulation in Lysosomes
    description: >
      Impaired CLN6/EGRESS-mediated ER export diminishes lysosomal enzyme
      delivery and may contribute to storage pathology, but the transition to
      ceroid accumulation is not established by the cited experiments.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:32597833
      reference_title: "A CLN6-CLN8 complex recruits lysosomal enzymes at the ER for Golgi transfer."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "In vitro and in vivo studies showed that CLN6 deficiency results in inefficient ER export of lysosomal enzymes and diminished levels of the enzymes at the lysosome."
      explanation: >
        The in vitro component supports the upstream cellular trafficking
        defect, not the downstream transition to ceroid storage.
    - reference: PMID:32597833
      reference_title: "A CLN6-CLN8 complex recruits lysosomal enzymes at the ER for Golgi transfer."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "In vitro and in vivo studies showed that CLN6 deficiency results in inefficient ER export of lysosomal enzymes and diminished levels of the enzymes at the lysosome."
      explanation: >
        The in vivo component supports lysosomal-enzyme depletion in a model,
        not the downstream transition to ceroid storage.
- name: Lipopigment Accumulation in Lysosomes
  biological_scale: CELLULAR
  conforms_to: "lysosomal_substrate_accumulation#Lysosomal Substrate Accumulation"
  subtypes:
  - CLN6 Kufs A
  - CTSF CLN13
  - DNAJC5 CLN4
  description: >
    Adult NCL neurons accumulate autofluorescent ceroid lipopigment in
    lysosomal storage bodies. This is the defining pathological hallmark of
    Kufs disease and the broader NCL group.
  cell_types:
  - preferred_term: neuron
    term:
      id: CL:0000540
      label: neuron
  biological_processes:
  - preferred_term: lysosomal transport
    modifier: DYSREGULATED
    term:
      id: GO:0007041
      label: lysosomal transport
  cellular_components:
  - preferred_term: lysosome
    term:
      id: GO:0005764
      label: lysosome
  evidence:
  - reference: PMID:21820099
    reference_title: "Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Autosomal-dominant adult-onset neuronal ceroid lipofuscinosis (ANCL) is characterized by accumulation of autofluorescent storage material in neural tissues and neurodegeneration"
    explanation: >
      Direct evidence that ANCL is defined by autofluorescent lysosomal
      storage in neural tissues.
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Ultrastructural examination of the pathology revealed fingerprint profiles as the characteristic inclusions, but they were not reliably seen in tissues other than brain."
    explanation: >
      Human CLN6-related Kufs disease shows characteristic ultrastructural
      storage inclusions in brain.
  - reference: PMID:23838030
    reference_title: "Classification and natural history of the neuronal ceroid lipofuscinoses."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The neuronal ceroid lipofuscinoses represent a group of disorders characterized by neurodegeneration and intracellular accumulation of an auto-fluorescent lipopigment."
    explanation: >
      The classification review supports lipopigment accumulation as a shared
      defining feature across the NCL group.
  downstream:
  - target: Autofluorescent ceroid lipopigment storage
    description: >
      Adult NCL lysosomal storage is directly observable as autofluorescent
      ceroid/lipopigment storage material in neural tissue.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:21820099
      reference_title: "Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Autosomal-dominant adult-onset neuronal ceroid lipofuscinosis (ANCL) is characterized by accumulation of autofluorescent storage material in neural tissues and neurodegeneration"
      explanation: >
        The defining lysosomal storage process is measured as
        autofluorescent storage material in neural tissue.
  - target: Progressive Neurodegeneration
    description: >
      Lysosomal lipopigment storage contributes to the progressive
      neurodegeneration that drives the clinical phenotype of adult NCL.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:21820099
      reference_title: "Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Autosomal-dominant adult-onset neuronal ceroid lipofuscinosis (ANCL) is characterized by accumulation of autofluorescent storage material in neural tissues and neurodegeneration"
      explanation: >
        The source reports storage and neurodegeneration together but does not
        experimentally establish the intervening causal steps.
- name: DNAJC5/CSPalpha Palmitoylation-Dependent Sorting Defect
  biological_scale: CELLULAR
  subtypes:
  - DNAJC5 CLN4
  description: >
    In autosomal dominant CLN4 (Parry disease), pathogenic variants in DNAJC5
    encoding cysteine-string protein alpha (CSPalpha) impair
    palmitoylation-dependent sorting. The initially reported substitution and
    deletion and a later cysteine-string-domain duplication all produce this
    cellular-localization defect.
  genes:
  - preferred_term: DNAJC5
    term:
      id: hgnc:16235
      label: DNAJC5
  cell_types:
  - preferred_term: neuron
    term:
      id: CL:0000540
      label: neuron
  biological_processes:
  - preferred_term: protein palmitoylation
    modifier: DYSREGULATED
    term:
      id: GO:0018345
      label: protein palmitoylation
  - preferred_term: protein localization to membrane
    modifier: DYSREGULATED
    term:
      id: GO:0072657
      label: protein localization to membrane
  evidence:
  - reference: PMID:21820099
    reference_title: "Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "These mutations-causing a deletion, p.Leu116del, and an amino acid exchange, p.Leu115Arg, respectively-are located within the cysteine-string domain of the protein and affect both palmitoylation-dependent sorting and the amount of CSPα in neuronal cells."
    explanation: >
      Cultured-neuron experiments directly support abnormal sorting of the two
      initially described CSPalpha variants.
  - reference: PMID:31919451
    reference_title: "Autosomal-dominant adult neuronal ceroid lipofuscinosis caused by duplication in DNAJC5 initially missed by Sanger and whole-exome sequencing."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "This variant leads to a duplication of the central core motif of the cysteine-string domain of CSPα and affects palmitoylation-dependent CSPα sorting in cultured neuronal cells similarly to two previously described CSPα variants, p.(Leu115Arg) and p.(Leu116del)."
    explanation: Cultured neuronal cells show the same sorting defect for the later in-frame duplication.
  downstream:
  - target: DNAJC5 Microautophagy-MAPS Imbalance
    description: >
      CLN4-associated DNAJC5 variants produce both abnormal
      palmitoylation-dependent sorting and uncoupling of microautophagy from
      MAPS, but the cited experiments do not isolate sorting failure as the
      direct cause of the protein-quality-control imbalance.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:31919451
      reference_title: "Autosomal-dominant adult neuronal ceroid lipofuscinosis caused by duplication in DNAJC5 initially missed by Sanger and whole-exome sequencing."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "This variant leads to a duplication of the central core motif of the cysteine-string domain of CSPα and affects palmitoylation-dependent CSPα sorting in cultured neuronal cells similarly to two previously described CSPα variants, p.(Leu115Arg) and p.(Leu116del)."
      explanation: Supports the upstream sorting defect in CLN4-associated variants.
    - reference: PMID:35506243
      reference_title: "Abnormal triaging of misfolded proteins by adult neuronal ceroid lipofuscinosis-associated DNAJC5/CSPα mutants causes lipofuscin accumulation."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "Importantly, uncoupling these two processes, as seen in cells lacking SLC3A2 or expressing ANCL-associated DNAJC5 mutants, generates DNAJC5-containing AFSMs resembling NCL patient-derived lipofuscin and induces neurodegeneration in a Drosophila ANCL model."
      explanation: Supports the downstream imbalance in CLN4-associated mutants without proving that abnormal sorting is its direct cause.
- name: DNAJC5/CSPalpha Functional Depletion and Presynaptic Dysfunction
  biological_scale: CELLULAR
  subtypes:
  - DNAJC5 CLN4
  description: >
    The original CLN4 study proposed that depletion of functional CSPalpha
    contributes to presynaptic dysfunction and progressive neurodegeneration.
    Because the source uses the hedged phrase "might cause," this is retained
    as an atomic emerging mechanism rather than asserted as a demonstrated
    causal chain.
  genes:
  - preferred_term: DNAJC5
    term:
      id: hgnc:16235
      label: DNAJC5
  cell_types:
  - preferred_term: neuron
    term:
      id: CL:0000540
      label: neuron
  evidence:
  - reference: PMID:21820099
    reference_title: "Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The resulting depletion of functional CSPα might cause in parallel the presynaptic dysfunction and the progressive neurodegeneration observed in affected individuals"
    explanation: The authors propose, rather than directly demonstrate, the presynaptic arm of the CLN4 mechanism.
  downstream:
  - target: Progressive Neurodegeneration
    description: Functional CSPalpha depletion is proposed to contribute to progressive neurodegeneration through presynaptic dysfunction.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:21820099
      reference_title: "Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "The resulting depletion of functional CSPα might cause in parallel the presynaptic dysfunction and the progressive neurodegeneration observed in affected individuals"
      explanation: The hedged mechanistic proposal supports an indirect partial edge, not a demonstrated causal transition.
- name: DNAJC5 Microautophagy-MAPS Imbalance
  biological_scale: CELLULAR
  subtypes:
  - DNAJC5 CLN4
  description: >
    DNAJC5 has coupled roles in ESCRT-dependent endosomal microautophagy and
    misfolding-associated protein secretion (MAPS). CLN4-associated mutants
    uncouple these protein-quality-control routes, generating
    DNAJC5-containing autofluorescent storage material in cells and
    neurodegeneration in a Drosophila model.
  genes:
  - preferred_term: DNAJC5
    term:
      id: hgnc:16235
      label: DNAJC5
  cell_types:
  - preferred_term: neuron
    term:
      id: CL:0000540
      label: neuron
  biological_processes:
  - preferred_term: microautophagy
    modifier: DYSREGULATED
    term:
      id: GO:0016237
      label: microautophagy
  evidence:
  - reference: PMID:35506243
    reference_title: "Abnormal triaging of misfolded proteins by adult neuronal ceroid lipofuscinosis-associated DNAJC5/CSPα mutants causes lipofuscin accumulation."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Here we report two functionally distinct but coupled chaperoning activities of DNAJC5, which jointly regulate lysosomal homeostasis: While endolysosome-associated DNAJC5 promotes ESCRT-dependent microautophagy, a fraction of perinuclear and non-lysosomal DNAJC5 mediates MAPS."
    explanation: Cell-based experiments define the coupled DNAJC5 microautophagy and MAPS activities.
  downstream:
  - target: Lipopigment Accumulation in Lysosomes
    description: >
      Uncoupling DNAJC5-dependent microautophagy and MAPS generates
      DNAJC5-containing autofluorescent storage material resembling patient
      lipofuscin.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:35506243
      reference_title: "Abnormal triaging of misfolded proteins by adult neuronal ceroid lipofuscinosis-associated DNAJC5/CSPα mutants causes lipofuscin accumulation."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "Importantly, uncoupling these two processes, as seen in cells lacking SLC3A2 or expressing ANCL-associated DNAJC5 mutants, generates DNAJC5-containing AFSMs resembling NCL patient-derived lipofuscin and induces neurodegeneration in a Drosophila ANCL model."
      explanation: >
        The cell-based portion directly links CLN4-associated mutants to
        lipofuscin-like autofluorescent storage material.
  - target: Progressive Neurodegeneration
    description: The same protein-quality-control imbalance induces neurodegeneration in an in vivo CLN4 model.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:35506243
      reference_title: "Abnormal triaging of misfolded proteins by adult neuronal ceroid lipofuscinosis-associated DNAJC5/CSPα mutants causes lipofuscin accumulation."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "Importantly, uncoupling these two processes, as seen in cells lacking SLC3A2 or expressing ANCL-associated DNAJC5 mutants, generates DNAJC5-containing AFSMs resembling NCL patient-derived lipofuscin and induces neurodegeneration in a Drosophila ANCL model."
      explanation: The in vivo Drosophila experiment supports neurodegeneration downstream of the imbalance.
- name: Cathepsin F Lysosomal Protease Dysfunction
  biological_scale: MOLECULAR
  subtypes:
  - CTSF CLN13
  description: >
    Recessive missense variants in CTSF are predicted to alter the structure
    and function of cathepsin F, a lysosomal cysteine protease, providing a
    plausible mechanism for the storage-disease phenotype across CLN13. A Ctsf
    knockout mouse recapitulates the light- and
    electron-microscopic pathology of Kufs disease.
  genes:
  - preferred_term: CTSF
    term:
      id: hgnc:2531
      label: CTSF
  cell_types:
  - preferred_term: neuron
    term:
      id: CL:0000540
      label: neuron
  biological_processes:
  - preferred_term: lysosomal proteolysis
    modifier: DYSREGULATED
    term:
      id: GO:0007039
      label: protein catabolic process in the vacuole
  molecular_functions:
  - preferred_term: cysteine-type peptidase activity
    modifier: DYSREGULATED
    term:
      id: GO:0008234
      label: cysteine-type peptidase activity
  evidence:
  - reference: PMID:23297359
    reference_title: "Cathepsin F mutations cause Type B Kufs disease, an adult-onset neuronal ceroid lipofuscinosis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "CTSF encodes cathepsin F, a lysosomal cysteine protease, dysfunction of which is a highly plausible candidate mechanism for a storage disorder like ceroid lipofuscinosis."
    explanation: >
      The human genetic study describes the lysosomal-protease mechanism as
      highly plausible but does not directly measure the full causal chain.
  - reference: PMID:23297359
    reference_title: "Cathepsin F mutations cause Type B Kufs disease, an adult-onset neuronal ceroid lipofuscinosis."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "re-examination of a previously published mouse knockout of Ctsf shows that it recapitulates the light and electron-microscopic pathological features of Kufs disease."
    explanation: >
      Mouse-model recapitulation of Kufs pathology supports the CTSF
      loss-of-function mechanism.
  downstream:
  - target: Lipopigment Accumulation in Lysosomes
    description: >
      Predicted cathepsin F dysfunction is proposed to impair lysosomal
      proteolysis and drive ceroid lipopigment storage in Type B Kufs disease.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:23297359
      reference_title: "Cathepsin F mutations cause Type B Kufs disease, an adult-onset neuronal ceroid lipofuscinosis."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "CTSF encodes cathepsin F, a lysosomal cysteine protease, dysfunction of which is a highly plausible candidate mechanism for a storage disorder like ceroid lipofuscinosis."
      explanation: >
        Supports a plausible link from cathepsin F dysfunction to storage;
        the omitted intermediates remain unresolved.
- name: Progressive Neurodegeneration
  biological_scale: TISSUE
  subtypes:
  - CLN6 Kufs A
  - CTSF CLN13
  - DNAJC5 CLN4
  description: >
    Adult NCL produces a progressive neurodegenerative phenotype manifesting
    as dementia, ataxia, and motor system dysfunction, with or without
    progressive myoclonus epilepsy depending on subtype.
  cell_types:
  - preferred_term: neuron
    term:
      id: CL:0000540
      label: neuron
  evidence:
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "MRI showed progressive cerebral and cerebellar atrophy."
    explanation: >
      Imaging evidence for progressive cerebral and cerebellar
      neurodegeneration in CLN6-related Kufs disease.
  - reference: PMID:23838030
    reference_title: "Classification and natural history of the neuronal ceroid lipofuscinoses."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The neuronal ceroid lipofuscinoses represent a group of disorders characterized by neurodegeneration and intracellular accumulation of an auto-fluorescent lipopigment."
    explanation: >
      The classification review supports neurodegeneration as a defining
      feature shared across adult-NCL branches.
  downstream:
  - target: Dementia
    description: >
      Ongoing CLN6-related neurodegeneration produces progressive dementia,
      which was invariable in the cited CLN6 cohort.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:30561534
      reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Dementia appeared to be an invariable accompaniment, although it could take a number of years to manifest and occasionally cognitive impairment preceded myoclonic seizures."
      explanation: >
        Dementia is reported as an invariable manifestation of CLN6-related
        Kufs disease.
  - target: Myoclonus
    description: >
      Neurodegeneration is associated with myoclonic seizures in CLN6 Kufs A;
      the intervening circuit mechanisms are not specified by the cohort.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:30561534
      reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "The typical presentation was of progressive myoclonus epilepsy with debilitating myoclonic seizures and relatively infrequent tonic-clonic seizures."
      explanation: >
        Progressive myoclonus epilepsy with debilitating myoclonic seizures
        is the typical presentation of Type A Kufs disease.
  - target: Cerebellar Ataxia
    description: >
      Neurodegeneration produces progressive ataxia, the most prominent
      motor feature of CLN6-related Kufs disease.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:30561534
      reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Ataxia was the most prominent motor feature."
      explanation: >
        Direct evidence that ataxia is the most prominent motor feature in
        CLN6-related Kufs disease.
  - target: Seizure
    description: >
      The progressive myoclonus epilepsy branch of CLN6-related Type A Kufs
      disease includes tonic-clonic seizures.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:30561534
      reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "The typical presentation was of progressive myoclonus epilepsy with debilitating myoclonic seizures and relatively infrequent tonic-clonic seizures."
      explanation: >
        The same progressive epilepsy syndrome includes tonic-clonic seizures
        as a downstream clinical manifestation.
  - target: Cerebral Atrophy
    description: >
      Progressive CLN6 disease and reported CTSF-related CLN13 can be
      accompanied by cerebral cortical atrophy on MRI.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:30561534
      reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "MRI showed progressive cerebral and cerebellar atrophy."
      explanation: >
        Neuroimaging directly documents progressive cerebral and cerebellar
        atrophy in CLN6-related Kufs disease.
    - reference: PMID:39720560
      reference_title: "Clinical Heterogeneity of Neuronal Ceroid Lipofuscinosis Type 13: A Case Report and Systematic Review of Literature."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Clinical radiologic scans revealed bilateral cortical atrophy, ventriculomegaly, a thin corpus callosum, and cerebellar vermian atrophy."
      explanation: The CLN13 index case documents bilateral cortical atrophy; this does not establish a frequency across CLN13.
  - target: Cerebellar Atrophy
    description: >
      Progressive CLN6 disease and reported CTSF-related CLN13 can be
      accompanied by cerebellar atrophy on MRI.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:30561534
      reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "MRI showed progressive cerebral and cerebellar atrophy."
      explanation: The CLN6 cohort directly documents progressive cerebellar atrophy on MRI.
    - reference: PMID:39720560
      reference_title: "Clinical Heterogeneity of Neuronal Ceroid Lipofuscinosis Type 13: A Case Report and Systematic Review of Literature."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Clinical radiologic scans revealed bilateral cortical atrophy, ventriculomegaly, a thin corpus callosum, and cerebellar vermian atrophy."
      explanation: The CLN13 index case documents cerebellar vermian atrophy; this does not establish a frequency across CLN13.
  - target: Extrapyramidal Motor Dysfunction
    description: >
      The phenotype-defined Type B branch includes extrapyramidal motor
      dysfunction; CTSF explains a minority of molecularly resolved cases.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:23838030
      reference_title: "Classification and natural history of the neuronal ceroid lipofuscinoses."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "Type B is characterized by dementia with cerebellar and/or extrapyramidal motor symptoms."
      explanation: The review supports the Type B association but does not establish the intervening causal mechanism or CTSF specificity.
  - target: Tremor
    description: CTSF/CLN13 adult NCL can present with cerebellar tremor.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:35359645
      reference_title: "Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "2nd-7th Seizures, myoclonus, cerebellar tremor, cognitive decline, depression, anxiety"
      explanation: The review table supports tremor as a CTSF/CLN13 feature but not a direct causal edge.
  - target: Depression
    description: Depression can be present at onset in CTSF/CLN13 adult NCL.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:35359645
      reference_title: "Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "2nd-7th Seizures, myoclonus, cerebellar tremor, cognitive decline, depression, anxiety"
      explanation: The review table supports depression as a CTSF/CLN13 feature but not a direct causal edge.
  - target: Anxiety
    description: Anxiety can be present at onset in CTSF/CLN13 adult NCL.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:35359645
      reference_title: "Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "2nd-7th Seizures, myoclonus, cerebellar tremor, cognitive decline, depression, anxiety"
      explanation: The review table supports anxiety as a CTSF/CLN13 feature but not a direct causal edge.
phenotypes:
- name: Dementia
  category: Nervous System
  subtypes:
  - CLN6 Kufs A
  - CTSF CLN13
  - DNAJC5 CLN4
  description: >
    Progressive dementia is a core adult-NCL manifestation. It was invariable
    in the cited CLN6 cohort; cognitive decline or progressive dementia is also
    described across CTSF CLN13 and DNAJC5 CLN4.
  phenotype_term:
    preferred_term: Dementia
    term:
      id: HP:0000726
      label: Dementia
    clinical_course: PROGRESSIVE
  evidence:
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Dementia appeared to be an invariable accompaniment, although it could take a number of years to manifest and occasionally cognitive impairment preceded myoclonic seizures."
    explanation: >
      Berkovic et al. document dementia as an invariable feature of
      CLN6-related Kufs disease.
  - reference: PMID:23838030
    reference_title: "Classification and natural history of the neuronal ceroid lipofuscinoses."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Clinical features include ataxia, progressive dementia, seizures, and myoclonus."
    explanation: The classification review documents progressive dementia in DNAJC5-related CLN4.
  - reference: PMID:35359645
    reference_title: "Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "2nd-7th Seizures, myoclonus, cerebellar tremor, cognitive decline, depression, anxiety"
    explanation: The adult-NCL table documents cognitive decline in CTSF/CLN13 disease.
- name: Myoclonus
  category: Nervous System
  subtypes:
  - CLN6 Kufs A
  - CTSF CLN13
  - DNAJC5 CLN4
  description: >
    Myoclonus is debilitating in CLN6 Kufs A and is also reported at onset in
    CTSF CLN13 and DNAJC5 CLN4.
  phenotype_term:
    preferred_term: Myoclonus
    term:
      id: HP:0001336
      label: Myoclonus
  evidence:
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The typical presentation was of progressive myoclonus epilepsy with debilitating myoclonic seizures and relatively infrequent tonic-clonic seizures."
    explanation: >
      Directly identifies debilitating myoclonic seizures as the typical
      presentation of Type A Kufs disease.
  - reference: PMID:35359645
    reference_title: "Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "2nd-7th Seizures, myoclonus, cerebellar tremor, cognitive decline, depression, anxiety"
    explanation: The adult-NCL table lists myoclonus at onset in CTSF/CLN13 disease.
  - reference: PMID:35359645
    reference_title: "Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "3rd-5th Seizures, action myoclonus, visual failure"
    explanation: The adult-NCL table lists action myoclonus at onset in DNAJC5/CLN4.
- name: Seizure
  category: Nervous System
  subtypes:
  - CLN6 Kufs A
  - CTSF CLN13
  - DNAJC5 CLN4
  description: >
    Generalized tonic-clonic seizures are relatively infrequent compared with
    myoclonus in CLN6 Kufs A; seizures are also reported at onset in CTSF Kufs
    B and DNAJC5 CLN4.
  phenotype_term:
    preferred_term: Seizure
    term:
      id: HP:0001250
      label: Seizure
  evidence:
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The typical presentation was of progressive myoclonus epilepsy with debilitating myoclonic seizures and relatively infrequent tonic-clonic seizures."
    explanation: >
      Supports tonic-clonic seizures as a clinical feature of Type A Kufs
      disease.
  - reference: PMID:35359645
    reference_title: "Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "2nd-7th Seizures, myoclonus, cerebellar tremor, cognitive decline, depression, anxiety"
    explanation: The adult-NCL table lists seizures at onset in CTSF/CLN13 disease.
  - reference: PMID:35359645
    reference_title: "Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "3rd-5th Seizures, action myoclonus, visual failure"
    explanation: The adult-NCL table lists seizures at onset in DNAJC5/CLN4.
- name: Cerebellar Ataxia
  category: Nervous System
  subtypes:
  - CLN6 Kufs A
  - DNAJC5 CLN4
  description: >
    Ataxia is the most prominent motor manifestation of CLN6 Kufs A and is also
    described in DNAJC5-related CLN4.
  phenotype_term:
    preferred_term: Progressive cerebellar ataxia
    term:
      id: HP:0002073
      label: Progressive cerebellar ataxia
  evidence:
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Ataxia was the most prominent motor feature."
    explanation: >
      Supports ataxia as the most prominent motor feature in CLN6-related
      Kufs disease.
  - reference: PMID:23838030
    reference_title: "Classification and natural history of the neuronal ceroid lipofuscinoses."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Clinical features include ataxia, progressive dementia, seizures, and myoclonus."
    explanation: The classification review documents ataxia in DNAJC5-related CLN4.
- name: Cerebral Atrophy
  category: Nervous System
  subtypes:
  - CLN6 Kufs A
  - CTSF CLN13
  description: >
    Progressive cerebral atrophy is documented in CLN6 Kufs A, and bilateral
    cortical atrophy was reported in a molecularly confirmed CLN13 case.
  phenotype_term:
    preferred_term: Cerebral cortical atrophy
    term:
      id: HP:0002120
      label: Cerebral cortical atrophy
    clinical_course: PROGRESSIVE
  evidence:
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "MRI showed progressive cerebral and cerebellar atrophy."
    explanation: >
      Direct neuroimaging evidence of progressive cerebral atrophy in
      CLN6-related Kufs disease.
  - reference: PMID:39720560
    reference_title: "Clinical Heterogeneity of Neuronal Ceroid Lipofuscinosis Type 13: A Case Report and Systematic Review of Literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Clinical radiologic scans revealed bilateral cortical atrophy, ventriculomegaly, a thin corpus callosum, and cerebellar vermian atrophy."
    explanation: The CLN13 index case adds direct MRI evidence of bilateral cortical atrophy without implying frequency.
- name: EEG photosensitivity
  category: Nervous System
  subtype: CLN6 Kufs A
  description: >
    Patients with CLN6-related Type A Kufs disease are usually highly
    photosensitive on EEG.
  phenotype_term:
    preferred_term: EEG with photoparoxysmal response
    term:
      id: HP:0010852
      label: EEG with photoparoxysmal response
  electrophysiology:
    electrophysiology_modality: EEG
  reports_on:
  - target: Progressive Neurodegeneration
    relationship: READOUT_OF
    direction: POSITIVE
    endpoint_context: DIAGNOSTIC
    interpretation: >
      EEG photosensitivity is an electrophysiologic readout of the CLN6 Kufs A
      neurologic disease state, not a causal consequence to place on a solid
      pathophysiology edge.
    evidence:
    - reference: PMID:30561534
      reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Patients were usually highly photosensitive on EEG."
      explanation: The cohort directly documents the EEG readout in CLN6-related Kufs disease.
  evidence:
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Patients were usually highly photosensitive on EEG."
    explanation: >
      Documents high EEG photosensitivity as a characteristic feature of
      CLN6-related Kufs disease.
- name: Cerebellar Atrophy
  category: Nervous System
  subtypes:
  - CLN6 Kufs A
  - CTSF CLN13
  description: >
    Progressive cerebellar atrophy is documented in CLN6 Kufs A, and
    cerebellar vermian atrophy was reported in a molecularly confirmed CLN13
    case.
  phenotype_term:
    preferred_term: Cerebellar atrophy
    term:
      id: HP:0001272
      label: Cerebellar atrophy
    clinical_course: PROGRESSIVE
  evidence:
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "MRI showed progressive cerebral and cerebellar atrophy."
    explanation: Directly documents progressive cerebellar atrophy in the CLN6 cohort.
  - reference: PMID:39720560
    reference_title: "Clinical Heterogeneity of Neuronal Ceroid Lipofuscinosis Type 13: A Case Report and Systematic Review of Literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Clinical radiologic scans revealed bilateral cortical atrophy, ventriculomegaly, a thin corpus callosum, and cerebellar vermian atrophy."
    explanation: The CLN13 index case adds direct MRI evidence of cerebellar vermian atrophy without implying frequency.
- name: Extrapyramidal Motor Dysfunction
  category: Nervous System
  subtype: CTSF CLN13
  description: >
    Extrapyramidal motor symptoms are part of the phenotype-defined Type B Kufs
    presentation; CTSF is one minority molecular cause of that phenotype.
  phenotype_term:
    preferred_term: Abnormality of extrapyramidal motor function
    term:
      id: HP:0002071
      label: Abnormality of extrapyramidal motor function
  evidence:
  - reference: PMID:23838030
    reference_title: "Classification and natural history of the neuronal ceroid lipofuscinoses."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Type B is characterized by dementia with cerebellar and/or extrapyramidal motor symptoms."
    explanation: Supports the legacy Type B phenotype; CTSF-specific penetrance is not established by this review.
- name: Tremor
  category: Nervous System
  subtype: CTSF CLN13
  description: Cerebellar tremor can be present at onset in CTSF/CLN13 adult NCL.
  phenotype_term:
    preferred_term: Tremor
    term:
      id: HP:0001337
      label: Tremor
  evidence:
  - reference: PMID:35359645
    reference_title: "Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "2nd-7th Seizures, myoclonus, cerebellar tremor, cognitive decline, depression, anxiety"
    explanation: The adult-NCL classification table lists cerebellar tremor for CTSF/CLN13.
- name: Depression
  category: Nervous System
  subtype: CTSF CLN13
  description: Depression can be present at onset in CTSF/CLN13 adult NCL.
  phenotype_term:
    preferred_term: Depression
    term:
      id: HP:0000716
      label: Depression
  evidence:
  - reference: PMID:35359645
    reference_title: "Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "2nd-7th Seizures, myoclonus, cerebellar tremor, cognitive decline, depression, anxiety"
    explanation: The adult-NCL classification table lists depression for CTSF/CLN13.
- name: Anxiety
  category: Nervous System
  subtype: CTSF CLN13
  description: Anxiety can be present at onset in CTSF/CLN13 adult NCL.
  phenotype_term:
    preferred_term: Anxiety
    term:
      id: HP:0000739
      label: Anxiety
  evidence:
  - reference: PMID:35359645
    reference_title: "Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "2nd-7th Seizures, myoclonus, cerebellar tremor, cognitive decline, depression, anxiety"
    explanation: The adult-NCL classification table lists anxiety for CTSF/CLN13.
imaging_findings:
- name: Cerebral Atrophy on MRI in CLN6
  modality: MRI
  subtype: CLN6 Kufs A
  imaging_finding_term:
    preferred_term: Cerebral cortical atrophy
    term:
      id: HP:0002120
      label: Cerebral cortical atrophy
  phenotype_term:
    preferred_term: Cerebral cortical atrophy
    term:
      id: HP:0002120
      label: Cerebral cortical atrophy
  located_in:
    preferred_term: cerebral cortex
    term:
      id: UBERON:0000956
      label: cerebral cortex
  diagnostic: false
  description: Structural MRI shows progressive cerebral atrophy in CLN6 Kufs A.
  evidence:
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "MRI showed progressive cerebral and cerebellar atrophy."
    explanation: Directly documents the structured cerebral MRI finding.
- name: Cerebral Atrophy on MRI in CLN13
  modality: MRI
  subtype: CTSF CLN13
  imaging_finding_term:
    preferred_term: Cerebral cortical atrophy
    term:
      id: HP:0002120
      label: Cerebral cortical atrophy
  phenotype_term:
    preferred_term: Cerebral cortical atrophy
    term:
      id: HP:0002120
      label: Cerebral cortical atrophy
  located_in:
    preferred_term: cerebral cortex
    term:
      id: UBERON:0000956
      label: cerebral cortex
  diagnostic: false
  description: Bilateral cortical atrophy was documented in a molecularly confirmed CLN13 index case.
  evidence:
  - reference: PMID:39720560
    reference_title: "Clinical Heterogeneity of Neuronal Ceroid Lipofuscinosis Type 13: A Case Report and Systematic Review of Literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Clinical radiologic scans revealed bilateral cortical atrophy, ventriculomegaly, a thin corpus callosum, and cerebellar vermian atrophy."
    explanation: Directly documents bilateral cortical atrophy in a molecularly confirmed CLN13 case without implying population frequency.
- name: Cerebellar Atrophy on MRI in CLN6
  modality: MRI
  subtype: CLN6 Kufs A
  imaging_finding_term:
    preferred_term: Cerebellar atrophy
    term:
      id: HP:0001272
      label: Cerebellar atrophy
  phenotype_term:
    preferred_term: Cerebellar atrophy
    term:
      id: HP:0001272
      label: Cerebellar atrophy
  located_in:
    preferred_term: cerebellum
    term:
      id: UBERON:0002037
      label: cerebellum
  diagnostic: false
  description: Structural MRI shows progressive cerebellar atrophy in CLN6 Kufs A.
  evidence:
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "MRI showed progressive cerebral and cerebellar atrophy."
    explanation: Directly documents the structured cerebellar MRI finding.
- name: Cerebellar Atrophy on MRI in CLN13
  modality: MRI
  subtype: CTSF CLN13
  imaging_finding_term:
    preferred_term: Cerebellar atrophy
    term:
      id: HP:0001272
      label: Cerebellar atrophy
  phenotype_term:
    preferred_term: Cerebellar atrophy
    term:
      id: HP:0001272
      label: Cerebellar atrophy
  located_in:
    preferred_term: cerebellum
    term:
      id: UBERON:0002037
      label: cerebellum
  diagnostic: false
  description: Cerebellar vermian atrophy was documented in a molecularly confirmed CLN13 index case.
  evidence:
  - reference: PMID:39720560
    reference_title: "Clinical Heterogeneity of Neuronal Ceroid Lipofuscinosis Type 13: A Case Report and Systematic Review of Literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Clinical radiologic scans revealed bilateral cortical atrophy, ventriculomegaly, a thin corpus callosum, and cerebellar vermian atrophy."
    explanation: Directly documents cerebellar vermian atrophy in a molecularly confirmed CLN13 case without implying population frequency.
biochemical:
- name: Autofluorescent ceroid lipopigment storage
  presence: INCREASED
  subtypes:
  - CLN6 Kufs A
  - CTSF CLN13
  - DNAJC5 CLN4
  context: >
    Adult NCL is defined pathologically by autofluorescent ceroid/lipopigment
    storage material in neural tissue. No specific local CHEBI or NCIT term was
    found for ceroid or lipofuscin, so this readout is represented without a
    forced biomarker term.
  readouts:
  - target: Lipopigment Accumulation in Lysosomes
    relationship: READOUT_OF
    direction: POSITIVE
    endpoint_context: DIAGNOSTIC
    interpretation: >
      Increased autofluorescent storage material reports the core lysosomal
      lipopigment accumulation node.
    evidence:
    - reference: PMID:21820099
      reference_title: "Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Autosomal-dominant adult-onset neuronal ceroid lipofuscinosis (ANCL) is characterized by accumulation of autofluorescent storage material in neural tissues and neurodegeneration"
      explanation: >
        Direct human evidence defines ANCL by autofluorescent storage material
        in neural tissue.
  evidence:
  - reference: PMID:21820099
    reference_title: "Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Autosomal-dominant adult-onset neuronal ceroid lipofuscinosis (ANCL) is characterized by accumulation of autofluorescent storage material in neural tissues and neurodegeneration"
    explanation: >
      Supports autofluorescent neural storage material as the defining adult
      NCL biochemical/pathologic readout.
  - reference: PMID:23838030
    reference_title: "Classification and natural history of the neuronal ceroid lipofuscinoses."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The neuronal ceroid lipofuscinoses represent a group of disorders characterized by neurodegeneration and intracellular accumulation of an auto-fluorescent lipopigment."
    explanation: >
      The classification review supports autofluorescent lipopigment
      accumulation as a shared NCL readout.
- name: Proteolysis-resistant ceroid deposits
  presence: INCREASED
  subtype: DNAJC5 CLN4
  context: >
    In DNAJC5-related autosomal dominant adult NCL (CLN4), depletion of
    functional CSPalpha is linked to lysosomal accumulation of misfolded,
    proteolysis-resistant proteins that form characteristic ceroid deposits;
    this readout is specific to the proposed DNAJC5/CLN4 mechanism rather than
    a marker for every adult-NCL branch.
  readouts:
  - target: DNAJC5 Microautophagy-MAPS Imbalance
    relationship: READOUT_OF
    direction: POSITIVE
    interpretation: >
      Proteolysis-resistant neuronal ceroid deposits report the lysosomal
      protein-quality-control consequence of DNAJC5/CSPalpha dysfunction.
    evidence:
    - reference: PMID:21820099
      reference_title: "Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "lysosomal accumulation of misfolded and proteolysis-resistant proteins in the form of characteristic ceroid deposits in neurons."
      explanation: >
        The original paper proposes this deposit as one arm of the CSPalpha
        mechanism; it does not validate it as a diagnostic assay.
  - target: Lipopigment Accumulation in Lysosomes
    relationship: READOUT_OF
    direction: POSITIVE
    interpretation: >
      These deposits are a DNAJC5-related manifestation of the broader adult
      NCL lysosomal lipopigment storage node.
    evidence:
    - reference: PMID:21820099
      reference_title: "Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "lysosomal accumulation of misfolded and proteolysis-resistant proteins in the form of characteristic ceroid deposits in neurons."
      explanation: >
        The proposed mechanism localizes the deposits to lysosomes but does not
        establish a validated clinical readout.
  evidence:
  - reference: PMID:21820099
    reference_title: "Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "lysosomal accumulation of misfolded and proteolysis-resistant proteins in the form of characteristic ceroid deposits in neurons."
    explanation: >
      Supports the authors' proposed proteolysis-resistant deposit mechanism in
      DNAJC5-related adult NCL.
- name: Cathepsin F lysosomal cysteine protease dysfunction
  presence: DYSREGULATED
  subtype: CTSF CLN13
  context: >
    The CTSF discovery study identifies cathepsin F as a lysosomal cysteine
    protease and describes its dysfunction as a highly plausible storage
    mechanism. It does not directly quantify enzyme activity in patients, so
    this is modeled as dysregulated rather than a measured diagnostic decrease.
  readouts:
  - target: Cathepsin F Lysosomal Protease Dysfunction
    relationship: READOUT_OF
    direction: PRESENT_ABSENT
    interpretation: >
      Presence of inferred cathepsin F dysfunction reports the CTSF-driven
      lysosomal proteolysis defect; no measured clinical assay is asserted.
    evidence:
    - reference: PMID:23297359
      reference_title: "Cathepsin F mutations cause Type B Kufs disease, an adult-onset neuronal ceroid lipofuscinosis."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "CTSF encodes cathepsin F, a lysosomal cysteine protease, dysfunction of which is a highly plausible candidate mechanism for a storage disorder like ceroid lipofuscinosis."
      explanation: >
        The paper explicitly calls this mechanism highly plausible rather than
        reporting a direct patient enzyme-activity measurement.
  evidence:
  - reference: PMID:23297359
    reference_title: "Cathepsin F mutations cause Type B Kufs disease, an adult-onset neuronal ceroid lipofuscinosis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "CTSF encodes cathepsin F, a lysosomal cysteine protease, dysfunction of which is a highly plausible candidate mechanism for a storage disorder like ceroid lipofuscinosis."
    explanation: >
      Supports inferred cathepsin F dysfunction without overclaiming a measured
      decrease or diagnostic endpoint.
- name: Lysosomal enzyme levels at the lysosome
  presence: DECREASED
  subtype: CLN6 Kufs A
  context: >
    In CLN6-deficient experimental systems, inefficient ER export of lysosomal
    enzymes leads to reduced lysosomal enzyme levels, a cellular biochemical
    readout of the CLN6/EGRESS trafficking defect.
  readouts:
  - target: CLN6 EGRESS Complex Lysosomal Enzyme Trafficking Defect
    relationship: READOUT_OF
    direction: NEGATIVE
    interpretation: >
      Lower lysosomal enzyme levels report impaired CLN6-dependent ER-to-Golgi
      lysosomal-enzyme transfer.
    evidence:
    - reference: PMID:32597833
      reference_title: "A CLN6-CLN8 complex recruits lysosomal enzymes at the ER for Golgi transfer."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "In vitro and in vivo studies showed that CLN6 deficiency results in inefficient ER export of lysosomal enzymes and diminished levels of the enzymes at the lysosome."
      explanation: >
        The in vitro component supports reduced lysosomal enzyme levels as a
        cellular readout of CLN6 deficiency.
    - reference: PMID:32597833
      reference_title: "A CLN6-CLN8 complex recruits lysosomal enzymes at the ER for Golgi transfer."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "In vitro and in vivo studies showed that CLN6 deficiency results in inefficient ER export of lysosomal enzymes and diminished levels of the enzymes at the lysosome."
      explanation: >
        The in vivo component supports reduced lysosomal enzyme levels as a
        model-organism readout of CLN6 deficiency.
  evidence:
  - reference: PMID:32597833
    reference_title: "A CLN6-CLN8 complex recruits lysosomal enzymes at the ER for Golgi transfer."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "In vitro and in vivo studies showed that CLN6 deficiency results in inefficient ER export of lysosomal enzymes and diminished levels of the enzymes at the lysosome."
    explanation: >
      The in vitro component supports reduced lysosomal enzyme levels as a
      biochemical/cellular consequence of CLN6 deficiency.
  - reference: PMID:32597833
    reference_title: "A CLN6-CLN8 complex recruits lysosomal enzymes at the ER for Golgi transfer."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "In vitro and in vivo studies showed that CLN6 deficiency results in inefficient ER export of lysosomal enzymes and diminished levels of the enzymes at the lysosome."
    explanation: >
      The in vivo component supports reduced lysosomal enzyme levels in a
      CLN6-deficient model context.
histopathology:
- name: Fingerprint Lipopigment Inclusions
  subtype: CLN6 Kufs A
  description: >
    The defining ultrastructural pathology of CLN6-related Kufs disease is
    autofluorescent lipopigment storage with fingerprint inclusion profiles
    in neurons. Curvilinear profiles, which are characteristic of variant
    late infantile NCL, are not a feature of CLN6-related Kufs disease.
    Detection of storage material can be unreliable in tissues other than
    brain, contributing to diagnostic difficulty.
  evidence:
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Ultrastructural examination of the pathology revealed fingerprint profiles as the characteristic inclusions, but they were not reliably seen in tissues other than brain."
    explanation: >
      Direct evidence that fingerprint profiles are the characteristic
      ultrastructural inclusions of CLN6-related Kufs disease.
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Curvilinear profiles, which are seen in the late infantile form, were not a feature."
    explanation: >
      Distinguishes adult Kufs ultrastructural pathology from the
      curvilinear inclusions of late-infantile NCL.
diagnosis:
- name: Genetic diagnosis
  description: >
    Diagnosis was traditionally dependent on demonstration of characteristic
    storage material via brain biopsy or autopsy. For the three classic adult
    branches modeled here, gene-first testing of CLN6, CTSF, and DNAJC5 can
    establish a molecular diagnosis and largely supersede invasive biopsy;
    broader adult-NCL presentations require an appropriately broad NCL panel.
  evidence:
  - reference: PMID:30561534
    reference_title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The diagnosis of Kufs remains challenging but, with the availability of genetic diagnosis, this will largely supersede the use of diagnostic biopsies, particularly as biopsies of peripheral tissues has unsatisfactory sensitivity and specificity."
    explanation: >
      Supports genetic testing as the preferred diagnostic strategy in
      suspected Kufs disease.
  - reference: PMID:21549341
    reference_title: "Kufs disease, the major adult form of neuronal ceroid lipofuscinosis, caused by mutations in CLN6."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Sequencing of CLN6 will provide a simple diagnostic strategy in this disorder, in which definitive identification usually requires invasive biopsy."
    explanation: >
      Arsov et al. propose CLN6 sequencing as a simple diagnostic strategy
      that can replace invasive biopsy.
- name: DNAJC5 insertion and duplication analysis
  description: >
    In unsolved autosomal dominant adult NCL, analysis should account for
    insertions or duplications in the DNAJC5 cysteine-string domain. A 30-bp
    duplication was initially missed by both standard Sanger sequencing and
    WES, so a negative routine result does not exclude this variant class.
  evidence:
  - reference: PMID:31919451
    reference_title: "Autosomal-dominant adult neuronal ceroid lipofuscinosis caused by duplication in DNAJC5 initially missed by Sanger and whole-exome sequencing."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "It was also missed by subsequent whole-exome sequencing (WES)."
    explanation: The family study documents a clinically important false-negative limitation of routine DNAJC5 testing.
  - reference: PMID:31919451
    reference_title: "Autosomal-dominant adult neuronal ceroid lipofuscinosis caused by duplication in DNAJC5 initially missed by Sanger and whole-exome sequencing."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Independently occurring variants in the genomic sequence of DNAJC5 encoding the cysteine-string domain of CSPα suggest that this region may be more prone to DNA replication errors and that insertions or duplications within this domain should be considered in unsolved ANCL cases."
    explanation: The authors explicitly recommend considering this variant class in unsolved adult NCL.
- name: Differential diagnosis and diagnostic delay
  description: >
    Adult NCL can be mistaken for acquired neurologic disorders when refractory
    epilepsy, cognitive decline, movement abnormalities, and progressive brain
    atrophy evolve over years. Early inclusion of adult NCL in the differential
    diagnosis may prevent ineffective immunotherapy or shunt procedures.
  evidence:
  - reference: PMID:39470529
    reference_title: "Adult-onset neuronal ceroid lipofuscinosis misdiagnosed as autoimmune encephalitis and normal-pressure hydrocephalus: A 10-year case report and case-based review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Initially diagnosed with autoimmune encephalitis, the patient was later diagnosed with normal-pressure hydrocephalus. A definitive diagnosis of adult-onset neuronal ceroid lipofuscinosis (ANCL) was established after 10 years of observation, utilizing biopsy and genetic testing."
    explanation: The case directly documents two misdiagnoses and a ten-year delay before definitive adult-NCL diagnosis.
  - reference: PMID:39470529
    reference_title: "Adult-onset neuronal ceroid lipofuscinosis misdiagnosed as autoimmune encephalitis and normal-pressure hydrocephalus: A 10-year case report and case-based review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Improved understanding of ANCL from both clinical and radiological perspectives, coupled with early consideration of differential diagnoses, could minimize unnecessary interventions and optimize patient care."
    explanation: The authors explicitly connect earlier differential consideration with avoiding unnecessary interventions.
treatments:
- name: Supportive Care
  description: >
    Adult NCL management is palliative and symptomatic. This entry does not
    infer supportive-care efficacy from a failed disease-directed treatment
    case and does not represent supportive care as disease-modifying.
  treatment_term:
    preferred_term: Supportive Care
    term:
      id: NCIT:C15747
      label: Supportive Care
  evidence:
  - reference: PMID:35359645
    reference_title: "Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "palliative care and symptomatic treatments which are still the main therapeutic interventions."
    explanation: >
      The NCL clinical review directly supports palliative and symptomatic
      management without claiming a disease-modifying effect.
- name: Antiseizure Pharmacotherapy
  description: >
    Antiseizure medications are used symptomatically to reduce seizure burden
    in NCL, including seizure-bearing adult branches. They are not represented
    as disease-modifying or as reliably producing complete seizure freedom.
  context: Symptomatic seizure management in CLN6 Kufs A, CTSF CLN13, and DNAJC5 CLN4.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: anticonvulsant agent
      term:
        id: NCIT:C264
        label: Anticonvulsant Agent
  target_phenotypes:
  - preferred_term: Seizure
    term:
      id: HP:0001250
      label: Seizure
  evidence:
  - reference: PMID:35359645
    reference_title: "Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "there is consensus that medications for epilepsy are used to alleviate seizure burden"
    explanation: >
      Expert clinical review supports antiseizure medication as symptomatic
      burden reduction rather than proof of disease modification.
discussions:
- discussion_id: cln4_visual_loss_classification_conflict
  prompt: Is visual loss a characteristic phenotype of DNAJC5-related CLN4?
  kind: CONTROVERSY
  status: RESOLVED
  attaches_to:
  - has_subtypes#DNAJC5 CLN4
  rationale: >
    A 2013 clinical classification review states that visual loss is absent in
    CLN4, whereas a 2022 overview table lists visual failure. Recording both
    statements preserves the source conflict without promoting the isolated
    table cell to a positive phenotype assertion.
  resolution_note: >
    Visual loss is not curated as a characteristic CLN4 phenotype; the explicit
    disease narrative is preferred over the conflicting overview-table cell.
  evidence:
  - reference: PMID:23838030
    reference_title: "Classification and natural history of the neuronal ceroid lipofuscinoses."
    supports: REFUTE
    evidence_source: OTHER
    snippet: "There is no visual loss in CLN4 disease."
    explanation: The disease-specific CLN4 narrative explicitly refutes visual loss as a characteristic feature.
  - reference: PMID:35359645
    reference_title: "Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Parry/CLN4 #162350 AD 20q13.33 CLN4/DNAJC5 CSPα (soluble protein): cytosol (vesicular membrane) 3rd-5th Seizures, action myoclonus, visual failure"
    explanation: The overview table supplies the conflicting positive phrase but no disease-specific supporting narrative.
datasets: []
references:
- reference: PMID:20301601
  title: "Neuronal Ceroid Lipofuscinoses Overview."
  tags:
  - GeneReviews
- reference: PMID:21549341
  title: "Kufs disease, the major adult form of neuronal ceroid lipofuscinosis, caused by mutations in CLN6."
- reference: PMID:21820099
  title: "Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis."
- reference: PMID:23297359
  title: "Cathepsin F mutations cause Type B Kufs disease, an adult-onset neuronal ceroid lipofuscinosis."
- reference: PMID:23838030
  title: "Classification and natural history of the neuronal ceroid lipofuscinoses."
- reference: PMID:30561534
  title: "Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features."
- reference: PMID:31919451
  title: "Autosomal-dominant adult neuronal ceroid lipofuscinosis caused by duplication in DNAJC5 initially missed by Sanger and whole-exome sequencing."
- reference: PMID:32597833
  title: "A CLN6-CLN8 complex recruits lysosomal enzymes at the ER for Golgi transfer."
- reference: PMID:35359645
  title: "Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview."
- reference: PMID:35506243
  title: "Abnormal triaging of misfolded proteins by adult neuronal ceroid lipofuscinosis-associated DNAJC5/CSPα mutants causes lipofuscin accumulation."
- reference: PMID:39470529
  title: "Adult-onset neuronal ceroid lipofuscinosis misdiagnosed as autoimmune encephalitis and normal-pressure hydrocephalus: A 10-year case report and case-based review."
- reference: PMID:39720560
  title: "Clinical Heterogeneity of Neuronal Ceroid Lipofuscinosis Type 13: A Case Report and Systematic Review of Literature."

📚

References & Deep Research

References

12

PMID:20301601

Neuronal Ceroid Lipofuscinoses Overview.

No top-level findings curated for this source.

PMID:21549341

Kufs disease, the major adult form of neuronal ceroid lipofuscinosis, caused by mutations in CLN6.

No top-level findings curated for this source.

PMID:21820099

Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis.

No top-level findings curated for this source.

PMID:23297359

Cathepsin F mutations cause Type B Kufs disease, an adult-onset neuronal ceroid lipofuscinosis.

No top-level findings curated for this source.

PMID:23838030

Classification and natural history of the neuronal ceroid lipofuscinoses.

No top-level findings curated for this source.

PMID:30561534

Kufs disease due to mutation of CLN6: clinical, pathological and molecular genetic features.

No top-level findings curated for this source.

PMID:31919451

Autosomal-dominant adult neuronal ceroid lipofuscinosis caused by duplication in DNAJC5 initially missed by Sanger and whole-exome sequencing.

No top-level findings curated for this source.

PMID:32597833

A CLN6-CLN8 complex recruits lysosomal enzymes at the ER for Golgi transfer.

No top-level findings curated for this source.

PMID:35359645

Neuronal Ceroid Lipofuscinosis: The Multifaceted Approach to the Clinical Issues, an Overview.

No top-level findings curated for this source.

PMID:35506243

Abnormal triaging of misfolded proteins by adult neuronal ceroid lipofuscinosis-associated DNAJC5/CSPα mutants causes lipofuscin accumulation.

No top-level findings curated for this source.

PMID:39470529

Adult-onset neuronal ceroid lipofuscinosis misdiagnosed as autoimmune encephalitis and normal-pressure hydrocephalus: A 10-year case report and case-based review.

No top-level findings curated for this source.

PMID:39720560

Clinical Heterogeneity of Neuronal Ceroid Lipofuscinosis Type 13: A Case Report and Systematic Review of Literature.

No top-level findings curated for this source.

Deep Research

1

Adult Neuronal Ceroid Lipofuscinosis Deep Research Fallback ▸

Adult Neuronal Ceroid Lipofuscinosis Deep Research Fallback

Date: 2026-05-13

Provider Attempts

falcon: just research-disorder falcon Adult_Neuronal_Ceroid_Lipofuscinosis started and remained silent past the agent timeout window; terminated without producing a usable artifact.
openai: just research-disorder openai Adult_Neuronal_Ceroid_Lipofuscinosis started and remained silent past the agent timeout window; terminated without producing a usable artifact.

Because no deep research provider returned a usable report, curation proceeded from MONDO:0019260, a bounded set of cached primary literature, and the existing group-level Neuronal Ceroid Lipofuscinosis research artifact.

Integrated Literature Synthesis

Adult neuronal ceroid lipofuscinosis (Kufs disease) is a rare adult-onset form of the NCL group of lysosomal storage neurodegenerative diseases. Disease typically begins in the third or fourth decade and is clinically divided into Type A (Kufs-A), a progressive myoclonus epilepsy with dementia, ataxia, and pyramidal or extrapyramidal motor signs, and Type B (Kufs-B), dominated by dementia with motor system dysfunction (cerebellar ataxia or extrapyramidal signs) generally without prominent myoclonic epilepsy. In contrast to the childhood NCL subtypes, retinopathy and visual loss are characteristically absent.

Adult NCL is genetically heterogeneous. Arsov and colleagues established that recessive pathogenic variants in CLN6 are the most common recessive cause of Kufs disease, particularly the Type A progressive myoclonus epilepsy phenotype, and provided systematic clinicopathologic and ultrastructural characterization showing fingerprint and granular lipopigment inclusions in CLN6-related cases (PMID:21549341). Subsequent exome work by Smith and colleagues identified homozygous and compound heterozygous CTSF mutations encoding cathepsin F as the major recessive cause of Kufs Type B (designated CLN13), implicating impaired lysosomal cysteine protease activity in the adult-onset disease group (PMID:23297359). The autosomal dominant adult-onset form CLN4 is caused by heterozygous mutations in DNAJC5 encoding cysteine-string protein alpha (CSPalpha), as established by Noskova and colleagues using linkage and exome sequencing in multiple unrelated families with autosomal dominant adult NCL (PMID:21820099).

Mechanistically, the three molecular etiologies converge on lysosomal and synaptic dysfunction. CLN6 encodes an ER-resident transmembrane protein required for normal lysosomal proteolytic homeostasis; loss of function leads to neuronal accumulation of autofluorescent ceroid lipopigment with fingerprint and granular ultrastructure. CTSF encodes the lysosomal cysteine protease cathepsin F; recessive loss-of-function impairs intralysosomal protein catabolism and drives lipopigment storage in neurons. Reviews emphasize that across NCL subtypes, including adult-onset forms, lysosomal storage and progressive neuronal loss are the core pathophysiologic features (PMID:30561534). DNAJC5/CSPalpha is a synaptic-vesicle-associated co-chaperone whose dominant pathogenic variants disrupt synaptic protein folding/quality control and SNARE-complex assembly, producing presynaptic dysfunction in addition to lipopigment storage; more recent work continues to characterize CLN4/DNAJC5 as a distinct dominant adult-onset NCL with predominant dementia and extrapyramidal features and to highlight palmitoylation/SNARE-related biology in disease pathogenesis (PMID:39470529).

No curative therapy currently exists for adult NCL. Management is supportive and primarily targets the clinical phenotype, including antiseizure pharmacotherapy for myoclonic and other seizures in Kufs-A. Genetic counseling is informed by the distinct recessive (CLN6, CTSF) and dominant (DNAJC5) inheritance patterns.

Key References

PMID:21549341 - Arsov et al. Kufs disease, the major adult form of neuronal ceroid lipofuscinosis, caused by mutations in CLN6.
PMID:21820099 - Noskova et al. Mutations in DNAJC5, encoding cysteine-string protein alpha, cause autosomal-dominant adult-onset neuronal ceroid lipofuscinosis (CLN4).
PMID:23297359 - Smith et al. Cathepsin F mutations cause Type B Kufs disease, an adult-onset neuronal ceroid lipofuscinosis.
PMID:30561534 - Review of neuronal ceroid lipofuscinoses summarizing lysosomal storage and progressive neurodegeneration across NCL subtypes, including adult-onset forms.
PMID:39470529 - Recent work on CLN4/DNAJC5-related adult NCL and CSPalpha synaptic biology in disease pathogenesis.

Notes on Scope

This fallback artifact is specific to adult-onset NCL (Kufs disease, MONDO:0019260) and complements the broader Neuronal_Ceroid_Lipofuscinosis-deep-research-asta.md group-level artifact. Curation focused on the three adult-onset genetic etiologies (CLN6, CTSF, DNAJC5/CLN4), the Type A vs Type B clinical distinction, and the absence of retinopathy that distinguishes adult NCL from childhood NCL subtypes.

Adult Neuronal Ceroid Lipofuscinosis

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References & Deep Research

References

Deep Research

Adult Neuronal Ceroid Lipofuscinosis Deep Research Fallback

Provider Attempts

Integrated Literature Synthesis

Key References

Notes on Scope