Melissa Wasserstein, MD, Chief of Pediatric Genetic Medicine at the Children’s Hospital at Montefiore, talks about Acid Sphingomyelinase Deficiency (ASMD), also known as Niemann-Pick Disease.
ASMD is an autosomal recessive genetic disorder caused by mutations in the SMPD1 gene that encodes for the enzyme acid sphingomyelinase (ASM), which metabolizes sphingomyelin.
ASMD is represented by a broad clinical spectrum of disease. In the more severe, infantile form, both central and peripheral symptoms are present while the less severe adult form, largely impacts the periphery.
Infantile ASMD has an onset in early infancy and 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.
Chronic visceral ASMD has a variable age of onset from infancy to adulthood. Patients with chronic visceral ASMD show similar morbidities of hepatosplenomegaly, progressive pulmonary dysfunction, thrombocytopenia, and dyslipidemia. These patients may develop clinically significant skeletal disease, cardiac valve abnormalities, stunted growth, and delayed puberty associated with the advancement of disease in the various organ systems.
In between these two extremes, patients with chronic neurovisceral ASMD present with similar symptoms as the chronic visceral form of the disease but may also develop neurologic symptoms of gross motor delay, ataxia and learning disability.
For more information, visit our ASMD page,