Niemann-Pick disease type B
NPD type B is a rare inborn error of metabolism of autosomal recessive inheritance.
Patients with Niemann-Pick disease type B (NPDB) have a benign course and prognosis, while Niemann-Pick disease type A (NPDA) and Niemann-Pick disease type C (NPDC) are always associated with severe neurological involvement. They are known to be complicated with varying degrees of prognosis-determining liver dysfunction.
Synopsis
short stature (less common)
cherry-red maculae (less common)
dyspnea
frequent respiratory infections
decreased pulmonary diffusion secondary to alveolar infiltration
diffuse reticular or finely nodular infiltrations
hepatomegaly
progressive liver failure (7655746)
splenomegaly
absence of neurologic manifestations
Pathology
Multiple visceral organs (lung, liver, spleen, kidney) contain foamy resident cells and histiocytes
large vacuolated foam cells (?NP cells?) on bone marrow biopsy
sea blue histiocytes
decreased platelets
Associations
generalized AL amyloidosis of kappa type (7655746)
Ultrastructure
foam cells with lamellar inclusions
LABORATORY ABNORMALITIES
Decreased acid sphingomyelinase activity
Increased LDL cholesterol
Increased triglycerides
Decreased HDL cholesterol
MISCELLANEOUS
Onset in infancy or childhood
Variable phenotype
More common in Ashkenazi Jews
Allelic disorder to Niemann-Pick disease type A (257200)
Etiology
Caused by mutations in the acid lysosomal sphingomyelin phosphodiesterase-1 gene (SMPD1) (MIM.607608)
See also
Niemann-Pick diseases (NPDs)
- Niemann-Pick disease type A (NPDA)
- Niemann-Pick disease type B (NPDB)
- Niemann-Pick disease type C (NPDC)
References
Takahashi T, Akiyama K, Tomihara M, Tokudome T, Nishinomiya F, Tazawa Y, Horinouchi K, Sakiyama T, Takada G. Heterogeneity of liver disorder in type B Niemann-Pick disease. Hum Pathol. 1997 Mar;28(3):385-8. PMID: 9042807