Acid sphingomyelinase deficiency, ASMD, historically known as Niemann-Pick disease (NPD) types A, A/B and B, is a rare, autosomal recessive disease caused by a deficiency of acid sphingomyelinase resulting from pathogenic variants in the SMPD1 gene1
- Sphingomyelin accumulates in cells mainly of the mononuclear phagocytic system
- Organs most affected: liver, spleen, lungs, nervous system, and skeletal system1
Estimated worldwide incidence is 0.4 to 0.6 in 100,000 newborns2
- Current numbers are likely underestimated3
- Specific types of ASMD are more prevalent in certain ethnic groups, e.g., ASMD type A (infantile neurovisceral ASMD) in persons of Ashkenazi Jewish descent3
Affects males and females equally4
Clinical Spectrum of ASMD
Gaucher Disease and Acid Sphingomyelinase Pathways
Although the inherited metabolic defect is different for Gaucher disease and ASMD, individuals affected with each disease will experience progressive substrate accumulation within the monocyte/macrophage system.
1. McGovern MM, et al. Genet Med. 2017;19(9):967–974. 2. McGovern MM, et al. Pediatrics. 2008;122(2):341–349. 3. Schuchman EH. J Inherit Metab Dis. 2007;30(5):654–663. 4. McGovern M, et al. Genet Med. 2013;15(8):618–623.
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