WHY IS IT CALLED NIEMANN-PICK?
The Niemann-Pick diseases are quite separate in terms of the fundamental cause but the similarities in clinical presentation have resulted in the naming of the diseases as Niemann-Pick, after two doctors who described the symptoms in the early part of the 20th century.
In 1914, a German paediatrician, Dr Albert Niemann, described the clinical presentation of children with the disease, but at that time little was known regarding the cellular or molecular explanation.
Then, in the 1920′s, the studies of Ludwig Pick, a German pathologist, provided evidence of a new disorder, one distinct from storage disorders previously described. Further investigations using cells taken from
the tissues of affected individuals in the mid and latter years of the century, resulted in an improved understanding of the diseases and their cause.
Since then there has been a considerable amount of investigation into these and other inherited diseases of metabolism. It was not until 1958 that the disease presentations were classified into type A, B and C.
In 1966 types A and B were identified with a lysosomal enzyme, acid sphingomyelinase. Type C, which in turn was further sub classified into types D, E and possibly others, remained the subject of investigation, mainly by the National Institute of Health near Washington, USA.
Although Niemann-Pick Disease Type C (NP-C) could be diagnosed through clinical, histological and biochemical means, it was not until 1997 that the genetic link was made, which accounted for 95% of the NP-C cases and is identified as NPC1. Subsequently, a further link was made with a second gene, NPC2, which accounted for 4% of the NP-C cases. In very rare instances, an individual has mutations in both of their NPC1 and NPC2 genes.
Some patients diagnosed with the disease remain to be accounted for.