Niemann-Pick Disease

Niemann-Pick Disease is a rare hereditary condition that affects 1 in 15,000 people but can be extremely life-threatening. Read and know what Niemann-Pick Disease is as well as its causes, symptoms, diagnosis and treatment.

What is Niemann-Pick Disease?

It is the name given to not one but a group of conditions that run down generations in the same family. These acquired conditions result in the collection of fatty substances (lipids) in the cells of the brain, liver and spleen.

Niemann-Pick Disease Types

Medical researchers and doctors have classified this disease into four forms. This classification is based on the particular genetic defect that is involved and the symptoms resulting out of it.

The four main types of Niemann-Pick Disease (NPD), based on this classification, are :

Niemann-Pick Disease Type A

This form of the disease is generally prevalent in early stages of infancy. This infantile disorder has a poor prognosis.

Niemann-Pick Disease Type B

This is a juvenile form of the disease. The symptoms of this condition generally develop in later stages of childhood or during adolescence. Types A and B of this condition are also known together as Type I. Types A and B are two of the most common forms of this disease.

Niemann-Pick Disease Type C

It is usually prevalent in children who are of school-going age. However, it may arise at any time within early infancy and adulthood. This is a more acute form that involves brain complications.

Niemann-Pick Disease Type D

This form is only prevalent in French Canadian individuals of Yarmouth County, Nova Scotia. It is now supposed to be a variation of Type C. Together, Types C and D are referred to as Type II.

A form of the disease has also been found to arise in individuals at the beginning of adulthood. Sometimes, this is referred to as Type E disorder.

Each type of NPD involves various organs. These may or may not include the respiratory system or central nervous system. Each of the NPD types can give rise to varied symptoms. These may occur at various stages of life, from babyhood to adulthood.

Niemann-Pick Disease Symptoms

The symptoms of Type A generally arise in the first few months of the life of patients. These involve:

  • Inflammation in abdomen within 3 – 6 months
  • Bright red blot in the eye
  • Difficulties in feeding without the aid of a feeding tube
  • Progressive loss of initial motor skills

Generally, symptoms of Type B are milder in nature. Very young children may suffer from abdominal inflammation and loss of motor skills, though there is little involvement of the nervous system and brain. Some patients may suffer from repeated infections of the respiratory system.

The symptoms of Type C and D are quite similar. These include:

  • Enlarged liver
  • Enlarged spleen
  • Enlarged lymph nodes
  • Seizures, which is common in Type C
  • Difficulties in moving limbs (Dystonia)
  • Jaundice at birth or shortly after it
  • Difficulties in learning
  • Development of dark patches on skin surface
  • Tremors
  • Decline in mental capabilities (Dementia)
  • Irregularities and slurring of speech
  • Sudden muscle tone loss that may result in falls (Cataplexy)
  • Difficulties in making up and down motions of the eyes (Vertical Supranuclear Gaze Palsy)
  • Unsteadiness and clumsiness in walking (Ataxia)

Children with this condition usually have low amount of white blood cells and platelets. Consequently, they suffer from anemia that makes them susceptible to infection and easy bruising.

Type E, which arises in adults, gives rise to symptoms like inflammation of the brain, enlargement of the spleen and neurological problems. This is a rare type of Niemann-Pick disease and not much is known about it.

However, the symptoms of all forms of this condition differ from one sufferer to another. The progression of this disease may also vary from person to person. Also, only a few symptoms of this disorder may be displayed in the early stages as well as the later stages of the condition.

What Causes Niemann-Pick Disease?

Type A and B of this disease occurs due to the lack of an enzyme known as Acid Sphingomyelinase (ASM) in the cells of the body. ASM helps in metabolization of a fatty substance known as Sphingomyelin, which is present in every cell of the human body.

Absence or improper functioning of the ASM enzyme can lead to an accumulation of Sphingomyelin within the cells. This results in death of cells, making proper functioning difficult for organs. However, Type A of this condition is supposed to develop due to racial preferences. Though it arises in individuals of all ethnic groups and races, it is found to have a greater preference for individuals belonging to the population of Ashkenazi (Eastern European) Jews.

Type C arises due to inability of the human body in decomposing cholesterols as well as other fats (lipids). This results in accumulation of a high amount of cholesterol in the spleen and liver. It also leads to a buildup of a high amount of other lipids in the human brain. It may also lead to reduced activity of ASM in certain cells. This form has been found to affect members of all ethnic groups though it is most commonly found to affect Puerto Rican individuals of Spanish origin.

Type D of this condition arises from a defect that intervenes with the motility of cholesterol between cells in the brain. It is now regarded to be a variation of type C. This type has only been found in the French Canadians of Yarmouth County, Nova Scotia.

Niemann-Pick Disease Diagnosis

The diagnosis of Type A and B of NPD is performed by evaluating the quantity of ASM in white blood cells. The test can be performed by using samples of bone marrow or blood. This test can reveal patients of this disease, but not its carriers. DNA tests can be conducted to identify carriers of NPD Type A and B.

Usually, a skin biopsy is conducted to identify Type C and D of NPD. Laboratory scientists will watch how the skin cells grow and study how they move and store cholesterol. DNA tests may also be done to look for the two genes that cause Niemann-Pick disease Type C.

Some other possible tests for this disease include:

  • Bone marrow aspiration
  • Sphingomyelinase assays
  • Slit-lamp eye exam
  • Liver biopsy (usually unnecessary)

Niemann-Pick Disease Treatment

At present, there is no good treatment for NPD Type A. Transplantation of bone marrow has been found to produce effective results in a few patients suffering from Type B. Research on possible cures is still on, with Gene Therapy and Enzyme Replacement Therapy being considered to be possible methods for treatment in future. A new cure, known as Miglustat, has recently been approved for curing Type C. No specific treatment still exists for Type D.

Though medical research has not proved it yet, a low-cholesterol, healthy diet is supposed to be beneficial for curing this disease. Medicines can provide relief from the symptoms of many disorders, such as seizures and cataplexy that may develop from this condition.

Niemann-Pick Disease Prognosis

Type A of NPD has poor prognosis. Infants with NPD Type A rarely survive over three years of age, despite treatment. Survival may be comparatively longer in patients with Type B. However, many of them need supplemental oxygen due to lung involvement. Sufferers of Type B and C usually have a better prognosis, with certain patients making it to adulthood. However, life expectancy can vary in patients with types C and D. Some patients die while still in childhood whereas others with less prominent symptoms may live into adulthood.

Niemann-Pick Disease Complications

Some of the main complications of this disorder are

  • Deafness
  • Death
  • Blindness
  • Brain damage, leading to mental retardation and slow development of physical skills

National Niemann-Pick Disease Foundation

The National Niemann-Pick Disease Foundation is an organization that supports as well as promotes research related to finding cures for all forms of Niemann-Pick Disease. It also extends support services for NPD sufferers as well as their families.

The organization is based in Wisconsin, USA. The registered address of this establishment is:

National Niemann-Pick Disease Foundation (NNPDF)

P.O. Box 49

401 Madison Avenue, Suite B

Fort Atkinson, WI 53538

Email: nnpdf@nnpdf.org

If your child is showing symptoms of this condition you have a family history of this disease, you should get in touch with an experienced medical professional. Early diagnosis and cure can help avoid some of the discomforting symptoms in future and increase chances of survival.

References:

http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002187/

http://emedicine.medscape.com/article/1114349-overview

http://www.wrongdiagnosis.com/n/niemann_pick_disease/intro.htm

http://www.umm.edu/ency/article/001207.htm

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