What is Niemann-Pick Type C Disease (NPC)?
Niemann-Pick Type C Disease (NPC) simply put is FATAL. It is a genetic, neurodegenerative disorder that consequently accumulates large amounts of cholesterol and other excess fats in the cells of the liver, spleen, and brain causing progressive deterioration of the nervous system. It usually starts to affect children of school age (4-7 years old) by interfering with their ability to metabolize cholesterol. Adult onset may also occur.
NPC is apart of the Lysosomal Storage Disorder family that encompasses about 50-60 diseases under the umbrella. You may have heard of more common Lysosomal Diseases such as Tay Sachs, Battens, Pompe Disease, Gaucher Disease, and many more.
Life Expectancy with Niemann Pick Type C Disease
Life expectancy with Niemann Pick Type C Disease (NPC) is younger than 20 years of age typically not living past their teenage years. However, there is no normal to go from because this disease is so rare most neurologists, geneticists, and Primary Care Physicians have never treated a child or adult with this disease. They estimate there has been around 500 cases diagnosed worldwide ever. It is projected that less than a 100 individuals are alive currently in the US.
For more information: Additional Resources
Additional information puts this disease into perspective according to the *American Journal of Medical Genetics Part A. “The average age of diagnosis for NPC1 disease was 10.4 years, with one-half of patients being diagnosed before the age of 6.9 years. The average age of death for NPC1 disease was 16.2 years, with one-half of patients dying before the age of 12.5 years.” This information was from 87 questionnaires returned from the year long study in 2007.
How is it diagnosed?
Niemann-Pick Type C Disease (NPC) is a very rare condition that presents many variables for those medical professionals who suspect a diagnosis such as NPC, it can be determined by taking a small piece of skin (“skin biopsy”), growing the cells (“fibroblasts”) in the laboratory, and studying their ability to transport and store cholesterol. DNA tests can further look for the two genes that cause Niemann-Pick Type C Disease (NPC) known as NPC1 gene and NPC2 gene. NPC1 gene accounts for 95% of all diagnoses.
Treatments
No clear and definitive therapy for Niemann-Pick Type C Disease (NPC) exists as of today. Researchers are making progress however as parents those timelines are not the same as the medical fields. The best strategy is through supportive care which therapies are available. These include medications to control seizures, abnormal posturing of limbs and tremors. Speech, occupational and physical therapy are also used to help with daily functioning.
Currently an “off label” drug called “Miglustat” or “Zavesca” manufactured by Actelion, is being used with patients with Niemann-Pick Type C Disease (NPC). “Off Label” means the alternative use from its original intended purpose (Gaucher’s Disease Type 1). Currently it isn't FDA approved (2009-early 2010) which makes it difficult for some families to try this experimental treatment. With being highly expensive as most rare disease drugs are, it is designed give hope for additional time with their loved ones but not cure NPC.
Overall the resolution to curing this disease will likely be a “cocktail” of remedies.
Side effects of Niemann Pick Type C Disease
The health of children & adults with NPC will deteriorate until ultimately Niemann-Pick Type C Disease (NPC) claims his or her life. With the progression of NPC it will present symptoms including the loss of swallowing (Dysphagia), laughing, remembering (Dementia), speaking (Aphasia), trouble moving eyes (Vertical Gaze Palsy), and often seizures occur. Patients often find themselves losing coordination (Gelastic Cataplexy), stumbling, falling (Ataxia), and will eventually need the aid of a wheelchair. This is all caused when brain cell function is blocked due to the cells inability to metabolize cholesterol.
Symptoms of Niemann Pick Type C Disease
- Enlarged liver and/or spleen
- Liver failure without neurological symptoms
- Difficulties with speech
- Development of dementia
- Seizures
- Jaundice at birth
- Early development of neurological problems
- Low muscle tone
- Delayed motor development beginning before age 2
- Sudden loss of muscle strength
- Progressive liver failure starting in infancy
- Early lung involvement without neurological disease
Autosomal Recessive Inheritance of NP-C
Niemann-Pick Type C disease is inherited. It is apart of a bigger family of 40-50 Lysosomal Storage Diseases. **”It is inherited in a autosomal recessive pattern which means both copies, or alleles, of the gene must be mutated (altered in such a way that function is impaired, in contrast to a polymorphism, in which the nucleotide sequence is altered but causes no functional disruption) for a person to be affected by the disorder. Most often, the parents of a child with an autosomal recessive disorder are not affected but are carriers of one copy of the altered gene. If both parents are carriers, there is a 25% chance with each pregnancy for an affected child.”
Below Dr. Marc Patterson of the Mayo Clinic in Rochester, MN
(**) http://en.wikipedia.org/wiki/Niemann%E2%80%93Pick_disease
