Understanding Niemann Pick Disease Type C: 

Symptoms, Diagnosis, and Management

What is Niemann Pick Disease Type C?

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Niemann Pick Disease Type C (NPC) is a rare lysosomal disorder that can appear at any age with variable symptoms. NPC is caused by variants in the NPC1 or NPC2 gene and affects approximately 1 in 100-000-120,000 individuals. Genetic variants in the NPC1 or NPC2 gene cause the buildup of cholesterol in the body which results in adverse symptoms in multiple systems of the body. 

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What are the symptoms of NPC?

Niemann Pick disease type C symptoms

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NPC presents with a variety of onsets and symptoms, and each individual's experience can vary widely. Common symptoms are outlined below: 

• Prolonged jaundice at birth
• Developmental delay
• Hepatosplenomegaly (enlarged liver and spleen) 
• Hypotonia (low muscle tone)
• Delayed motor development
• Clumsiness
• Dysarthria (slurred speech)
• Cataplexy (often triggered by laughter)
• Abnormal eye movements (inability to move eyes up and down)
• Hearing loss 
• Progressive ataxia
• Speech delay
• Dysphagia (difficulty swallowing)
• Seizures
• Cognitive decline (similar to dementia - but occurring in childhood)
• Psychiatric or behavioral problems (presenting similarly to ADHD, schizophrenia, etc)
• Lung disease
• Liver failure
• Failure to thrive

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How is NPC diagnosed?

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Diagnosing NPC requires genetic testing. The primary methods used include:

• Lysosomal disorder, epilepsy, metabolic disorder, or other targeted panels: These panels test for multiple genes that might be responsible for the symptoms.
• Whole Exome Sequencing (WES): This test examines all the protein-coding regions of the genes.
• Whole Genome Sequencing (WGS): This comprehensive test looks at the entire DNA.
• Chromosomal Microarray Analysis: Although rarely used, this can identify larger genetic changes that might be responsible for the symptoms.

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If you or a loved one is experiencing symptoms associated with NPC, Probably Genetic offers no-cost genetic testing and genetic counseling to patients with confirmed eligibility. 

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To be eligible, patients must be experiencing NPC symptoms and not have already received a genetic diagnosis. Probably Genetic is dedicated to offering as many tests as possible and commits to re-reviewing previously waitlisted applications as our testing capacity grows. 

What are common misdiagnoses for NPC?

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Due to the overlap of symptoms with other conditions and the rarity of the disease, NPC can often be misdiagnosed. Common misdiagnoses include:

• Cerebral Palsy
• Gaucher Disease
• Schizophrenia
• ADHD
• Early-onset Alzheimer’s
• Autism

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How is NPC treated?

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Currently, there is no single, approved therapeutic intervention for NPC. Treatment focuses on managing the symptoms and may vary significantly from one individual to another. Common treatments include:

• Medications: To control seizures and manage other symptoms.
• Therapies: Physical, occupational, and speech therapies to support development.
• Nutritional Support: To manage cholesterol buildup 

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As research continues, clinical trials and new therapies are being developed, providing hope for better management and treatment options in the future.

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Life Expectancy and Prognosis

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Life expectancy for this condition depends significantly on the age when symptoms first appear, ranging from early childhood mortality to several decades of survival in adult-onset cases.

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Early Infantile Onset (Before Age 1): Infants diagnosed before their first birthday face the most severe prognosis and may not survive beyond early school age.

Childhood Onset: Children who develop symptoms during childhood typically have a life expectancy extending into their late teens to twenties.

Adult-Onset Cases: Adults diagnosed with this condition generally have the longest survival rates, often living 10 to 20 years or more following diagnosis.

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No-Cost Genetic Testing Program

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Probably Genetic offers a no-cost genetic testing program for individuals suspected of having NPC. The process to apply is straightforward:

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1. Begin the Online Symptom Assessment: Describe the symptoms you or a loved one is experiencing.

2. Complete Your Profile: Provide additional necessary information, including your address for the sample collection kit.

3. See if You Qualify: You’ll be notified via email regarding your eligibility.

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Building a Support Network

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Connecting with others who understand your experiences is crucial. The National Niemann Pick Disease Foundation and Ara Parseghian Medical Research Fund offer resources and community support to help families manage the challenges of NPC.

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By leveraging these resources, patients and families can gain better insights into managing NPC and connecting with others who share similar experiences. Whether you're seeking information, community support, or considering genetic testing, these resources can help you navigate the journey with NPC.

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