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PubMed This is a summary of 9 peer-reviewed journal articles Updated
Neurology · Neuronal Ceroid Lipofuscinosis Type 13

Misdiagnoses and Related Conditions

At a Glance

CLN13 disease can resemble early-onset Alzheimer’s, frontotemporal dementia, Parkinson’s disease, or psychiatric illness because memory, behavior, and movement symptoms overlap. Symptoms cannot identify the gene or Kufs type; molecular testing is needed.

Because CLN13 is exceptionally rare and its symptoms develop in adulthood, it is frequently hidden behind more common clinical labels. Understanding the difference between these early misdiagnoses—and the historical difference between Kufs disease Type A and Type B—is essential for making sense of the diagnostic journey [1][2].

Common Diagnostic Mimics

Because the early signs often involve personality changes, memory lapses, or motor stiffness, CLN13 is commonly confused with other neurodegenerative diseases:

  • Early-Onset Alzheimer’s Disease: Both cause progressive memory loss, but CLN13 often includes motor symptoms that appear earlier than in typical Alzheimer’s [2][3].
  • Frontotemporal Dementia (FTD): CLN13 frequently begins with “frontal” symptoms, such as poor judgment or emotional apathy, making it appear clinically identical to FTD or FTD with parkinsonism [3][4].
  • Parkinson’s Disease / Movement Disorders: When tremors and stiffness are prominent early on, doctors may initially diagnose a primary movement disorder [3][5].
  • Psychiatric Illness: Early behavioral shifts can lead to a diagnosis of depression, bipolar disorder, or late-onset schizophrenia before physical decline is recognized [6].

In some cases, patients are misdiagnosed with other rare conditions like Huntington’s disease or prion disease because the clinical overlap is so significant [1].

Kufs Type A vs. Kufs Type B: Clinical Phenotypes

Historically, doctors divided adult-onset Batten disease into clinical categories based on the patient’s primary symptoms. It is important to understand that these labels are phenotypic descriptions, not strict genetic rules. While certain genes are closely associated with certain types, there is significant overlap [7][4].

Clinical Phenotype Primary Symptoms Most Commonly Associated Genes
Kufs Type A Progressive Myoclonus Epilepsy (PME): Severe seizures and sudden muscle jerks, often with ataxia [7][4]. Often CLN6 (recessive) or DNAJC5 (dominant, sometimes termed CLN4) [7].
Kufs Type B Dementia and Motor Dysfunction: Changes in thinking, personality, parkinsonism, and ataxia [7][4]. Often CTSF (recessive, termed CLN13) [7].

Why Symptoms Cannot Assign a Genetic Type

While the table above outlines the “classic” presentations, modern genetic research has shown that the boundaries between Type A and Type B are not rigid [4][5].

  • Overlapping Symptoms: Some people with a confirmed CTSF mutation (typically Type B) experience significant seizures and muscle jerks that mimic Type A [4].
  • Variable Families: There are documented families where siblings with the exact same genetic mutation displayed different versions of the disease—one presenting more like Type A and another like Type B [5].

Because clinical symptoms alone cannot reliably determine the underlying genetic cause or the inheritance pattern, molecular testing is required to establish the specific gene involved [7]. Identifying the exact gene (such as CTSF) is the only way to accurately assess family inheritance risks and provide the most informed supportive care [8][9].

Common questions in this guide

What conditions can be mistaken for CLN13 disease?
CLN13 can resemble early-onset Alzheimer’s disease, frontotemporal dementia, Parkinson’s disease or another movement disorder, and some psychiatric illnesses. Huntington’s disease and prion disease may also be considered because symptoms can overlap. Progressive movement problems, seizures, or myoclonus may provide clues, but they do not establish the diagnosis.
How is CLN13 different from frontotemporal dementia?
Both conditions can begin with changes in personality, judgment, or emotional responsiveness, so symptoms alone may not distinguish them. CLN13 may also cause progressive motor problems and, in some people, seizures or myoclonus. Molecular genetic testing is needed to determine whether a CTSF-related disorder is present.
What do Kufs disease Type A and Type B mean?
Kufs Type A and Type B are historical clinical descriptions of adult-onset Batten disease. Type A is mainly associated with progressive myoclonus epilepsy, including seizures, muscle jerks, and ataxia, while Type B more often involves dementia, personality changes, parkinsonism, and ataxia. These labels describe patterns of symptoms and are not strict genetic categories.
Can symptoms show which gene is causing CLN13 disease?
No. Symptoms can overlap between Kufs Type A and Type B, and people with the same gene change may have different clinical patterns. Molecular genetic testing is needed to identify the specific gene and clarify the inheritance pattern.
Why is identifying a CTSF gene change important?
CTSF gene changes are commonly associated with the adult-onset CLN13 or Kufs Type B pattern, although symptoms can overlap. Confirming the gene helps clarify family inheritance risks and supports more informed monitoring and supportive care.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.If seizures are part of the clinical picture, why are we focusing on a CTSF diagnosis rather than other NCL types?
  2. 2.Does our genetic report indicate a recessive variant or a dominant one, and how certain is that interpretation?
  3. 3.Can you explain how the specific behavioral changes we are seeing differ clinically from standard frontotemporal dementia (FTD)?
  4. 4.Were other neurodegenerative conditions like Huntington's, early-onset Alzheimer's, or prion disease thoroughly ruled out?
  5. 5.How does knowing the exact genetic cause change our approach to monitoring and symptom management?

Questions For You

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References

References (9)
  1. 1

    Diagnosis and misdiagnosis of adult neuronal ceroid lipofuscinosis (Kufs disease).

    Berkovic SF, Staropoli JF, Carpenter S, et al.

    Neurology 2016; (87(6)):579-84 doi:10.1212/WNL.0000000000002943.

    PMID: 27412140
  2. 2

    Exome sequencing in a consanguineous family clinically diagnosed with early-onset Alzheimer's disease identifies a homozygous CTSF mutation.

    Bras J, Djaldetti R, Alves AM, et al.

    Neurobiology of aging 2016; (46()):236.e1-6.

    PMID: 27524508
  3. 3

    Novel frameshift CTSF mutation causing kufs disease type B mimicking frontotemporal dementia-parkinsonism.

    Gultekin M, Tufekcioglu Z, Baydemir R

    Neurocase 2022; (28(1)):107-109 doi:10.1080/13554794.2022.2038635.

    PMID: 35139754
  4. 4

    Mutated CTSF in adult-onset neuronal ceroid lipofuscinosis and FTD.

    van der Zee J, Mariën P, Crols R, et al.

    Neurology. Genetics 2016; (2(5)):e102 doi:10.1212/NXG.0000000000000102.

    PMID: 27668283
  5. 5

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

    Ghayal NB, Roemer SF, Tipton PW, et al.

    Neurology. Genetics 2025; (11(1)):e200227 doi:10.1212/NXG.0000000000200227.

    PMID: 39720560
  6. 6

    Long-term follow-up of two siblings with adult-onset neuronal ceroid lipofuscinosis, Kufs type A.

    Özkara Ç, Gündüz A, Coşkun T, et al.

    Epileptic disorders : international epilepsy journal with videotape 2017; (19(2)):147-151 doi:10.1684/epd.2017.0911.

    PMID: 28587997
  7. 7

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

    Berkovic SF, Oliver KL, Canafoglia L, et al.

    Brain : a journal of neurology 2019; (142(1)):59-69 doi:10.1093/brain/awy297.

    PMID: 30561534
  8. 8

    Novel compound heterozygous mutations causing Kufs disease type B.

    Wang C, Xu H, Yuan Y, et al.

    The International journal of neuroscience 2018; (128(6)):573-576 doi:10.1080/00207454.2017.1403439.

    PMID: 29120254
  9. 9

    Adult-Onset Recessive Cerebellar Ataxia and Severe Multisystem Disease-Associated Genes: Hypomorphic Alleles and Clinical Interpretation Pitfalls.

    Cipriano L, Petillo R, Priolo M, D'Ambrosio P

    Genes 2026; (17(7)) doi:10.3390/genes17070758.

    PMID: 42510798

This page explains CLN13 misdiagnoses and Kufs disease phenotypes for informational purposes only and does not constitute medical advice. A neurologist and genetics professional should interpret your symptoms and genetic results.

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