Niemann-Pick Type A
Niemann-Pick Type A disease (NPA) is a fatal neurodengenerative disorder that is quite serve stricking in infancy. Typically by age six months of age the patient experiences an enlarged liver and spleen, vomitting, and difficulity in feeding. Some children with NPA have a “cherry-red spot” in the retina of the eye (This is common in Tay-Sachs). Death from NPA occurs between 2-4 years of age. The estimate is one out of 75 Ashkenazi Hews are carriers of Niemann-Pick Type A.
- Motor-Skill and coordination issues
- Spasticity (progressive)
- Potential of jaundice at birth with liver failure
- A Cherry Red Spot in the eye (determined by an eye specialist
- Distended abdomen (liver and spleen)
- Averaged age of death by age 2-3
- Rapid Neurological decline
As a whole Niemann-Pick Disease (A, B, C) is an inherited in a autosomal recessive manner. Both parents carry a mutated gene with a 1 and 4 chance (25%) with each pregnancy to have an affected child. Biochemcially, Niemann-Pick Type A disease is the deciciency of an enzyme called sphingomyelinase (ASM). ASM normally degrades a fatty substance better known as sphingomyelin. The defectiveness of the enzyme leads to the accumulation of sphingomyelin in the liver and spleen (primarily), brain, and lymph nodes. NPA has little to no ASM production.
Treatment, Diagnosis, and Screening
Currently there is no treatment for Niemann-Pick Type A disease (NPA). Approximately 1,200 Type A & B cases have been diagnosed world wide. It is reported that a majority of cases reported are from Ashkenazi Jewish descent.
Diagnosis for NPA can be acheived by testing blood by measuring the ASM activity in the white blood cells.
Discovery of Niemann-Pick Disease Gene
The discovery of the gene responsible for Niemann-Pick disease came to light in 1997. This discovery will help propel research on future potential effective treatments. Gene therapy has shown usefulness in mice that have NPA.
Niemann-Pick Type B
Niemann-Pick Type B (NPB) is similar to Niemann-Pick Type A. Both are also known as Acid Sphingomyelinase Deficiency (ASMD) because of the deficiency of acid sphingomyelinase (ASM).. A patient with NPB lives into late childhood or adulthood. Patients generally experience little to no neurological set backs as Type A & C. Out of all three types of Niemann-Pick disease (A, B, C), Type B has the longest potential life span.
- Enlarged Liver & Spleen
- Respiratory problems
- Cardiovascular stress due to the previous two symptoms can lead to heart disease later in life