Genetic Testing for Niemann-Pick Disease (NP), Types A and B
Niemann-Pick disease type A, also referred to as ASMD, is one of the most severe genetic disorders affecting infants, and its diagnosis can take a family completely by surprise.¹ Because carriers are not affected by the disease themselves, most parents don't find out they have a mutation, a change in the gene, until after their child’s diagnosis. Carrier screening for Niemann-Pick disease looks for changes in the gene linked to types A and B, so you can know your risk before you're expecting or already planning a pregnancy.
What Is Niemann-Pick Disease, Types A and B?
Niemann-Pick disease types A and B happen when the body can't properly break down a fatty substance called sphingomyelin, which then builds up in the liver, spleen, and lungs. In type A, it builds up in the brain as well.¹
- Type A is the most severe, causing rapid neurological decline that's typically fatal between ages 2 and 3.
- Type B is milder, mainly affecting the liver, spleen, and lungs, with most people living into adulthood.¹
Types A and B affect roughly 1 in 250,000 people in the general population.¹
Niemann-Pick disease also includes a type C, but this is a separate condition caused by changes in a different gene and an underlying problem with cholesterol transport, not a breakdown of sphingomyelin.
SMPD1
SMPD1 is the gene associated with Niemann-Pick disease types A and B (also known as ASMD). Most cases happen when a person inherits a non-working copy of SMPD1 from each parent, which leaves the body without enough of the enzyme needed to break down sphingomyelin.¹
Why Niemann-Pick Disease Testing Matters
Testing prior to conception provides you with the most information. Knowing your carrier status ahead of time helps with planning if your child is later diagnosed and needs treatment. In 2022, the FDA approved the first enzyme replacement therapy (ERT) for Niemann-Pick disease types A and B. For people with type B in particular, it can meaningfully reduce liver and spleen size, improve lung function, and raise low platelet counts.¹ Since treatment doesn’t reach the brain, it can't treat the neurological effects of type A. However, a quicker diagnosis provides earlier access to supportive care, and a faster start to treatment for the symptoms it does address.¹
It’s important to know that most states are not required to test for Niemann-Pick disease as part of newborn screening. Very few states currently screen for Niemann-Pick disease at birth.² Knowing your carrier status ahead of time arms you with information regardless of your state's newborn screening policy. Niemann-Pick disease types A and B are inherited in a pattern called autosomal recessive. A carrier has one working copy of the SMPD1 gene and one nonworking copy. Carriers don’t have the disease themselves, because the one working copy is enough.¹ If both parents are carriers, each pregnancy has a 25% chance (1 in 4) of the child inheriting a nonworking copy from each parent and being affected with Nieman-Pick disease, a 50% chance (1 in 2) of the child being an unaffected carrier like the parents, and a 25% (1in 4) chance of the child inheriting a working copy of the gene from each parent.¹
Your Odds of Carrying the SMPD1 Gene
1 in 90 people of Ashkenazi Jewish descent carry a change in SMPD1, the gene linked to Niemann-Pick disease types A and B.³
Niemann-Pick disease type A occurs with far greater frequency in people of Ashkenazi Jewish descent than in the general population, while type B has been reported across many ethnic backgrounds.¹ Regardless of ethnicity, testing is recommended for individuals of all backgrounds.⁴
Who Should Consider Niemann-Pick Disease Testing?
Niemann-Pick disease carrier screening is especially relevant for anyone with Ashkenazi Jewish ancestry, but it's worth considering more broadly too.
You Have Ashkenazi Jewish Ancestry
Since carrier frequency for Niemann-Pick disease is so much higher in this population, this alone is often reason enough to get screened, regardless of family history.
A Parent or Sibling Has Been Diagnosed With Niemann-Pick Disease
If Niemann-Pick disease runs in your immediate family, your own chance of carrying a genetic change is higher than average, and screening other relatives can help the whole family understand their risk.
You're Planning Ahead of Pregnancy
Because newborn screening for Niemann-Pick disease isn't available everywhere, knowing your carrier status before conceiving is often the most reliable way to find out early.²
Your Partner Has Already Screened Positive
If your partner knows they carry a change in the gene linked to Niemann-Pick disease, screening is the only way to know in advance whether your child could be at risk.
You're Using a Sperm or Egg Donor
Donor gametes carry the same genetic considerations as a partner would, so screening applies here too.⁵
Easy Steps from Home to Results
Order Your Kit
Register online and receive a saliva collection kit shipped directly to your home within a few days.
Collect Your Sample
Provide a saliva sample at home, following the instructions included in your kit.
Lab Analysis
Your sample is analyzed at a CLIA-accredited laboratory using DNA sequencing.
Receive Results
Receive your results within 3 to 4 weeks. You can choose to schedule a complimentary consultation with a certified genetic counselor to review your findings, and we recommend doing so for any result other than a straightforward negative.
Affordable Access for Everyone
Insurance Billing
Self-Pay Option
Understanding Your Results
Positive (Carrier)
A positive result means you carry one working copy and one nonworking copy of the SMPD1 gene.¹ You are not affected by Niemann-Pick disease, but you can pass the nonworking copy of the gene to a child. If you're planning a pregnancy, your partner should also be screened in advance, since your child's risk depends on whether your partner carries a change in the same gene.⁵
Negative Result
A negative result means you have a significantly lower chance of being a carrier for Niemann-Pick disease without bringing it all the way to zero, since no screen can detect every possible gene change.⁴
If You and Your Partner Are Both Carriers
If both partners carry a change in SMPD1, each pregnancy has a 25% chance of being affected by Niemann-Pick disease.¹ If you are pregnant, prenatal tests for Niemann-Pick disease, such as chorionic villus sampling (CVS) or amniocentesis, can diagnose early whether a current pregnancy is affected.⁸ Genetic counseling is strongly recommended at this stage, and every jscreen result comes with access to a board certified genetic counselor to walk through what your specific results mean and what your options are. We strongly recommend testing prior to conception, which allows for the greatest range of reproductive options.
Take the Next Step for Your Family’s Health with Carrier Screening
Frequently Asked Questions
Can you test for Niemann-Pick disease?
Yes. Genetic testing for Niemann-Pick disease can be done before or during pregnancy. Carrier screening checks whether you or your partner carry a change in SMPD1, the gene linked to Niemann-Pick disease types A and B.
What do Niemann-Pick disease genetic testing results mean?
Results generally fall into two categories. A negative result means you're very unlikely to be a carrier, though it can't rule out every possible change. A positive result means you carry one working and one nonworking copy of SMPD1, with no health effects to you personally.
How do you test for Niemann-Pick disease from home?
With a genetic carrier screen, the whole process happens from home. You order a kit online, provide a saliva sample using the instructions included, and mail it back using the prepaid materials in the kit. Your sample is analyzed at a CLIA-accredited laboratory, and results are typically available within 3 to 4 weeks of your sample arriving at the lab.
What diagnostic tests are available for Niemann-Pick disease during pregnancy?
If both partners are found to be carriers, diagnostic tests for Niemann-Pick disease, such as chorionic villus sampling (CVS) or amniocentesis, can determine whether a current pregnancy is affected, rather than waiting until birth.6
Do I need genetic counseling after my results?
While genetic counseling isn't required, it's strongly recommended, especially if your result is positive.6 Every screen through jscreen includes access to a complimentary consultation with a board certified genetic counselor, who can explain what your specific results mean and what your options are going forward.
What happens if my partner and I are both carriers of Niemann-Pick Disease?
Each pregnancy would have a 25% chance of being affected by Niemann-Pick disease.¹ At that point, most people work with a genetic counselor to talk through their options, which can include prenatal diagnostic testing during a current pregnancy, or other family planning approaches if you haven't conceived yet.6
References
- Acid Sphingomyelinase Deficiency. National Organization for Rare Disorders (NORD). Last updated January 2, 2025. Accessed August 14, 2026.
https://rarediseases.org/rare-diseases/acid-sphingomyelinase-deficiency/ - The Importance of Newborn Screening for Niemann-Pick Disease. National Niemann-Pick Disease Foundation (NNPDF). Accessed August 14, 2026.
https://nnpdf.org/the-importance-of-newborn-screening-for-niemann-pick-disease/ - Niemann-Pick Disease Types A and B. Norton & Elaine Sarnoff Center for Jewish Genetics. Revised August 2022. Accessed August 14, 2026.
https://www.jewishgenetics.org/genetic-disorders/search-genetic-disorders/niemann-pick-disease-types-a-and-b/ - Geberhiwot T, Wasserstein M, Wanninayake S, et al. Consensus clinical management guidelines for acid sphingomyelinase deficiency (Niemann-Pick disease types A, B and A/B). Orphanet J Rare Dis. Published April 17, 2023. Accessed August 14, 2026.
https://link.springer.com/article/10.1186/s13023-023-02686-6 - Carrier Screening for Family Planning. Mayo Clinic Health System. Published June 23, 2023. Accessed August 14, 2026.
https://www.mayoclinichealthsystem.org/hometown-health/speaking-of-health/carrier-screening-for-family-planning - Santoli CMA, Dotters-Katz SK, Sparks TN, Kuller JA. An Overview of Current Prenatal Genetic Screening and Diagnosis Guidelines. Pregnancy. Published April 10, 2025. Accessed August 14, 2026.
https://doi.org/10.1002/pmf2.70016