Niemann-Pick disease type A is a severe, neurodegenerative disease characterized by an enlarged liver and spleen, recurring lung infections, psychomotor regression, and early death. It is caused by genetic variants in the SMPD1 gene, which affect the breakdown of sphingomyelin.
Niemann-Pick disease type A is more prevalent in Ashkenazi Jewish populations than the general population. Between 1 in 80 and 1 in 100 people of Ashkenazi Jewish heritage carry a defective SMPD1 gene and are known as carriers. However, effective carrier screening programs and prenatal testing has reduced the actual birth incidence.
Take this test to find out if you are a genetic carrier for a SMPD1 variant and are at risk of passing it to your children.
Niemann-Pick disease type A is caused by variants in the SMPD1 gene. This gene provides instructions for the acid sphingomyelinase (ASM) enzyme. ASM converts sphingomyelin fats (lipids) into another type of lipid called ceramide. Affected individuals cannot produce a functional ASM enzyme, causing lipids to accumulate in cells. This accumulation results in cell death, thereby affecting the function of many organs.
Niemann-Pick disease type A is an autosomal recessive disorder, meaning that an individual must inherit two defective copies of the SMPD1 gene for symptoms to occur.
This test detects three genetic variants in the SMPD1 gene which account for approximately 97% of Niemann-Pick disease type A cases and carriers in individuals of Ashkenazi Jewish descent.
Understanding your carrier status for these variants will help you understand the risk of passing a variant to your children.
- Massively enlarged liver and spleen (hepatosplenomegaly)
- Failure to gain weight and grow at expected rates
- Progressive loss of mental abilities and movement (psychomotor regression)
- Swollen lymph nodes
- A cherry-red spot eye abnormality
- Difficulty feeding
- Poor muscle tone
- Lung disease causes recurrent lung infections
How It Works
Step 1: Sign up for a free DNA Access account.
Step 2: Upload your DNA markers to DNA Access.
Step 3: Log in to your account to access your results when they are ready.