KMC Forums - Niemann-Pick (please PLEASE read)

Yes.. I know... but, My best friend's brother was diagnosed with this disease (Type B) It's rather new and VERY uncommmon..PLEASE...just take a few moments to look over.

Bradley just turned 5 Wed......

What Is Niemann-Pick Disease?

Niemann-Pick Disease ("Niemann-Pick") is actually a term for a group of diseases which affect metabolism and which are caused by specific genetic mutations. The three most commonly recognized forms of the disease are Types A, B and C.

Types A and B Niemann-Pick are both caused by the deficiency of a specific enzyme activity, acid sphingomyelinase (ASM). This enzyme is ordinarily found in special compartments within cells called lysosomes and is required to metabolize a special lipid, called sphingomyelin. If ASM is absent or not functioning properly, this lipid cannot be metabolized properly and is accumulated within the cell, eventually causing cell death and the malfunction of major organ systems.

Types A and B are both caused by the same enzymatic deficiency and there is a growing concensus that the two forms represent opposite ends of a continuous scale. People with Type A generally have little or no ASM production while those with Type B have up to 10 times the level of ASM.

While both Type A and B have ASM activity that is significantly lower than normal, the clinical prognosis for these two groups of patients is very different. Type A Niemann-Pick is a severe neurologic disease which generally leads to death by 2 to 3 years of age. It is believed that the majority of Niemann-Pick cases are Type A.

In contrast, patients with Type B generally have little or no neurologic involvement and may survive into late childhood or adulthood. Type B individuals usually have enlarged livers and spleens and experience respiratory problems.

Patients with intermediate ASM activity tend to have more neurological problems than Type B but fewer problems than Type A. Because there is not a precise correlation between ASM activity and neurological involvement, it is not possible to accurately predict the severity of the disease by enzyme testing.

Types C, D, and E Niemann-Pick, although similar in name to Types A and B, are very different at the biochemical and genetic level. Patients are not able to metabolize cholesterol and other lipids properly within the cell. Consequently, excessive amounts of cholesterol accumulate within the liver and spleen and excessive amounts of other lipids accumulate in the brain.

Because the defect in metabolism of Types C, D, and E occasionally leads to a secondary reduction in ASM activity in some cells, all five types were originally called Niemann-Pick Disease.

Type C Niemann-Pick has 300 to 350 cases diagnosed world wide. It is believed that the number of people affected is higher but it is often difficult for the correct diagnosis to be made. Type C usually affects children of school age but there is considerable variation in the time of onset and variation in the progression of the disease..

Type D Niemann-Pick has only been found in the French Canadian population of Yarmouth County, Nova Scotia. Geneological evidence indicates that Joseph Muise (c. 1679 - 1729) and Marie Amirault (1684 - c. 1735) are common ancestors to all Type D cases. This couple are the most likely origin for the Type D variant.

A Type E Niemann-Pick has also been suggested based on a number of adults who have been found with some of the same tissue and chemical changes as Type C, but with very late adult onset of symptoms. There is growing evidence that the metabolic processes in Type E individuals are only partially disfunctional, slowing the onset and progression of symptoms.

Genetic research conducted since 1997 strongly indicates that Types C, D, and E are variations of the same disease. On this website, discussion of Type C applies to Types D and E as well.

Niemann-Pick affects all segments of the population with cases reported from North America, South America, Europe, Africa, Asia, and Australia. However a higher incidence of has been found in certain populations:

Ashkenazi Jewish population (types A and B)
French Canadian population of Nova Scotia (type D)
Maghreb region (Tunisia, Morocco, and Algeria) of North Africa (type B)
Spanish-American population of southern New Mexico and Colorado (type C)

__________________
~* I am just a shadow of what I am to become, one of ten thousand jedi. I am a murderer. *~

Lari-Crai Prilin: Fate Changes, a fan-fic by yours truly