Niemann-Pick disease type C’s unpredictability makes diagnosis challenging1,2
Niemann-Pick disease type C may be hard to diagnose due to the heterogeneity of symptom presentation and because individual symptoms overlap with other common diseases. This variance from person-to-person can make it difficult to recognize and result in delayed diagnosis.1-3
Disease progression can be rapid or slow making symptom recognition more difficult. Compared to pre-adolescent onset patients (<15 yrs), adolescent (>15 yrs) and adult-onset patients may be even more challenging to diagnose due to2:
• Differing presentation from younger children
• More psychiatric symptom involvement
• Less hepatosplenomegaly presentation
As a genetic disease characterized by neurodegeneration, NPC can cause many combinations of symptoms.2
Some NPC symptoms are consistent with other more common diseases making identification difficult1,2,4
NPC symptom categories:
Ambulation
Fine motor skills
Speech
Memory
Symptoms:
Ataxia
Cataplexy
Dementia
Dysarthria
Dystonia
Hypotonia
Psychosis
For illustrative purposes only
More common conditions like Alzheimer's disease and schizophrenia have similar symptoms to NPC, which can make NPC difficult to identify.4
NPC can also cause just one or two neurological symptoms alongside other physical or mental health problems, highlighting the importance of reading between the signs to recognize NPC.2
Multidisciplinary healthcare coordination is essential to timely diagnosis and treatment1
NPC can have a drastic impact on the ability to live everyday life for affected individuals and place an ever-increasing burden on their families, but may be hard to diagnose due to heterogeneity of symptom presentation and symptoms that overlap with other diseases.1-3
To diagnose as early as possible, collaborating with the management team of referring physician, treatment specialists, and treatment supporting physicians can include1:
- Clinical geneticists
- Dietitians and Nutritionists
- Gastroenterologists
- Genetic counselors
- Neurologists
- Nurse practitioners
- Occupational/Physical therapists
- Ophthalmologists
- Pediatricians
- Physician assistants
- Primary care physicians
- Psychiatrists
Testing options on the path to diagnosis
In an unpredictable, irreversible, and degenerative disease such as NPC, timely diagnosis is imperative.1,3
Testing is readily available and may be available free of charge for those who qualify.
Types of tests:
Considered the first step to NPC diagnosis. Biomarkers currently analyzed include1:
- oxysterols
- lysosphingolipids*
- bile acids
Gene panels for some of the symptoms of NPC often include screenings for mutations in NPC1 and NPC2. Single gene sequencing should be conducted in cases with a high clinical suspicion of NPC.1
Filipin test† of skin sample on cultured fibroblasts to look for unesterified cholesterol accumulation within the lysosomes.1
In addition, a medical history and clinical examination can aid in proper diagnosis. NPC is not curable, but management with available treatments is possible.1,3
*Primarily lysosphingomyelin-509.
†No longer standard and only used as confirmatory evidence following inconclusive genetic testing.
†No longer standard and only used as confirmatory evidence following inconclusive genetic testing.
Testing, diagnosing, and treating NPC as early as possible is critical for appropriate management of the condition.1
