Niemann–Pick disease, type C

Niemann–Pick disease, type C (NPC) is a lysosomal storage disorder that affects the body's ability to transport cholesterol and other fatty substances (lipids) inside of cells. This leads to the accumulation of these substances within various tissues of the body, including the brain, liver, and spleen.

Genetics

NPC is caused by mutations in either the NPC1 or NPC2 genes. These genes are responsible for producing proteins that are essential for the normal transport of cholesterol and lipids within cells. Mutations in these genes disrupt this process, leading to the characteristic accumulation of lipids in the cells of individuals with NPC.

Symptoms

The symptoms of NPC can vary widely but often include:

• Hepatosplenomegaly (enlarged liver and spleen)
• Ataxia (lack of muscle coordination)
• Dysarthria (difficulty speaking)
• Dysphagia (difficulty swallowing)
• Gelastic cataplexy (sudden loss of muscle tone triggered by laughter)
• Seizures
• Dementia

Diagnosis

Diagnosis of NPC typically involves a combination of clinical evaluation, genetic testing, and biochemical tests. One common biochemical test is the filipin test, which examines the ability of cells to esterify cholesterol.

Treatment

There is currently no cure for NPC, but treatments are available to manage symptoms and improve quality of life. One such treatment is miglustat, which has been shown to slow the progression of neurological symptoms in some patients. Supportive therapies, such as physical therapy and speech therapy, are also important components of care.

Prognosis

The prognosis for individuals with NPC varies depending on the severity of the disease and the age of onset. Early-onset forms of NPC tend to be more severe and progress more rapidly, while later-onset forms may have a slower progression.

Related Pages

• Lysosomal storage disorder
• Cholesterol
• NPC1
• NPC2
• Hepatosplenomegaly
• Ataxia
• Dysarthria
• Dysphagia
• Seizures
• Dementia