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What is ASMD disease?

About ASMD disease

Acid sphingomyelinase deficiency (ASMD) is a rare, genetic condition that can be passed down in families. It has historically been called Niemann-Pick disease and has three main types in order of increasing severity: type B, type A/B, and type A. ASMD belongs to a larger group of conditions known as lysosomal storage disorders.1,2

ASMD lasts a lifetime and is progressive, which means it can get worse over time. Because symptoms can be hard to notice or may look like other conditions, it is sometimes missed or misdiagnosed. The sooner ASMD is properly diagnosed, the sooner it can be managed.1

 

Video: What is ASMD disease?

If you suspect ASMD, talk to your doctor

Individuals with ASMD may face diagnostic delays of around 3 to 5 years on average.3,4 If you think you or someone in your family might have ASMD, talk to your doctor about possible next steps, such as getting tested.

 

 

How is ASMD diagnosed?

Diagnostic testing is initiated when a doctor suspects their patient may have ASMD based on their signs and symptoms.  

Enzyme testing for ASMD

The recommended method for diagnosing ASMD is a blood test that measures the activity of an enzyme called acid sphingomyelinase (sfin-goh-my-uh-lin-ase), or ASM. If the test shows decreased ASM activity, then the ASMD diagnosis is confirmed.5

Genetic testing for ASMD

Genetic testing may also be performed following the enzyme test, as additional confirmation and to determine which pathogenic variants are present.5

Since ASMD can be inherited, if one family member has been diagnosed with ASMD, relatives should consider talking with their doctor about family screening or possibly getting tested.5

 

 

What causes ASMD?

ASMD is a sphingomyelinase deficiency disease caused by changes in a gene called SMPD1. The role of the SMPD1 gene is to produce the ASM enzyme.

Changes in the SMPD1 gene can prevent the body from being able to make enough ASM. ASM is needed to break down a fatty substance called sphingomyelin (sfin-goh-my-uh-lin). Without enough ASM, sphingomyelin builds up in major organs such as the liver, lungs, and spleen. This buildup can lead to complications over time, including enlarged or damaged organs.2,5

 

 

What are the symptoms of ASMD?

ASMD can affect multiple organs and body systems (groups of organs that work together to perform specific functions). Symptoms can present differently from person to person and can begin at any age—from infancy through adulthood.5
Common ASMD symptoms* may include:

  • Coughing and trouble breathing caused by lung scarring or infections
  • Swollen belly from enlarged spleen (splenomegaly) or liver (hepatomegaly)
  • Easy bruising and bleeding from low platelet counts
  • Gastrointestinal (abdominal) issues and diarrhea
  • Pain in the limbs or joints
  • Bone breaks from weakened bones, due to osteopenia or osteoporosis
  • Ongoing tiredness (chronic fatigue)
  • Low muscle tone (hypotonia)
  • Poor muscle control that affects movement
  • Developmental delays
  • Tingling in the hands and feet
  • Cherry red spot on the retina of the eye
  • Heart issues

*These are not all possible symptoms, nor do all people living with ASMD have all the listed symptoms.1,5

 

How is ASMD managed?

Because ASMD affects many parts of the body, care plans usually involve a team of specialists to manage all the different symptoms.1 Taking an active role in symptom management can give you a greater sense of control. 

Your healthcare team is your best resource for support and guidance and will help create a care plan that fits your personal needs. 

HCP with clipboard and patient

Helpful resources and support for ASMD

Additional support and resources are available for people living with ASMD and their caregivers. For additional information about personalized support, contact our CareConnect team.

Call 1-800-745-4447 (for English, press 3; para español, oprima 7) or email info@CareConnectPSS.com.

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References

1 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. Apr 17 2023;18(1):85. doi:10.1186/s13023-023-02686-6

2 Bajwa H, Azhar W. Niemann-Pick Disease. StatPearls. 2025.

3 Doerr A, Farooq M, Faulkner C, et al. Diagnostic odyssey for patients with acid sphingomyelinase deficiency (ASMD): Exploring the potential indicators of diagnosis using quantitative and qualitative data. Mol Genet Metab Rep. Mar 2024;38:101052. doi:10.1016/j.ymgmr.2024.101052

4 McGovern MM, Wasserstein MP, Giugliani R, et al. A prospective, cross-sectional survey study of the natural history of Niemann-Pick disease type B. Pediatrics. Aug 2008;122(2):e341-9. doi:10.1542/peds.2007-3016

5 McGovern MM, Dionisi-Vici C, Giugliani R, et al. Consensus recommendation for a diagnostic guideline for acid sphingomyelinase deficiency. Genet Med. Sep 2017;19(9):967-974. doi:10.1038/gim.2017.7

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