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11 Cards in this Set
- Front
- Back
Clinical Niemann-Pick Disease
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Inheritance
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Autosomal recessive; sphingomyelin phosphodiesterase 1 (SMPD 1) gene locus 11 p 15.4 15.1 (types A, B)
Type C gene locus 18p |
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Prenatal
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CVS/amniocentesis sphingomyelinase enzyme assay from cultured chorionic villus tissue/amniotic fluid cells
DNA analysis |
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Incidence
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Type A most common over 50% are Ashkenazi Jews; a few hundred cases reported; M=F
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Age at Presentation
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Type A infancy
Type B infancy to childhood Type C childhood |
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Pathogenesis
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Mutations in SMPD 1 results in acid sphingomyelinase deficiency in types A and B with subsequent accumulation of sphingomyelin in characteristic foam cells within all organs, increased in brain (except type B), liver, spleen, lymph nodes, and lungs; cholesterol esterification defect in type C with normal sphingomyelinase
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Clinical
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Type A
Skin Xanthomas; yellow brown, waxy induration on exposed surfaces Central Nervous System Progressive psychornotor deterioration, hypotonicity, muscle weakness Gastrointestinal Hepatosplenornegaly, emaciated appearance fai lure to thrive, vomiting Lymphatics Generalized enlarged lymph nodes Eyes Blindness, cherry red spots Ear Nose Throat Deafness Lungs Bronchopneumonia, infiltration of foam cells Type B CNS spared, otherwise similar to type A Type C Developmental delay, hepatosplenornegaly, progressive psychomotor deterioration |
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D/Dx
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Gaucher disease (p. 310)
Tay Sachs disease |
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Lab
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Serum sphingomyelinase assay
Bone marrow biopsy |
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Management
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Supportive care parenteral nutrition, antibiotics, transfusions, splenectomy
Bone marrow transplant type B |
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Prognosis
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Type A death by 2 to 3 years of age secondary to progressive deterioration, fatal pulmonary infection
Type B death in adolescence; may survive into adulthood Type C death in adolescence |