Melissa Wasserstein, MD, from the Children’s Hospital at Montefiore, talks about Acid Sphingomyelinase Deficiency (ASMD), also known as Niemann-Pick Diseases type A or type B.
ASMD is a genetic disorder caused by mutations in the SMPD1 gene that encodes for acid sphingomyelinase (ASM), an enzyme that metabolizes sphingomyelin.
Niemann-Pick disease type A, or Infantile ASMD, is marked by progressive and eventually massive hepatosplenomegaly, progressive neurological symptoms, pulmonary damage, and cholesterol abnormalities. Other symptoms include respiratory and gastrointestinal, cherry red maculae, feeding problems, failure to thrive, and irritability.
The milder form of the disease, referred to Niemann-Pick type B or chronic visceral ASMD can begin in infancy oradulthood. Patients with chronic visceral ASMD show similar peripheral symptoms of hepatosplenomegaly, progressive pulmonary dysfunction, thrombocytopenia, and dyslipidemia. These patients may also develop clinically significant skeletal disease, cardiac valve abnormalities, stunted growth, and delayed puberty associated with the advancement of disease in the various organ systems.
As Dr. Wasserstein explains in this video, clinical trials involving enzyme replacement therapy to treat Niemann-Pick disease type B are underway.
It should be noted that the most common type of Niemann-Pick disease is type C. It is due to mutations in MPC1 orMPC2 genes and not the SMDP1 gene.