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40 Cards in this Set
- Front
- Back
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what types of disorders are lipid metabolism disorders?
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lysosomal storage diseases
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what are the three GM2 gangliosidoses?
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Tay-Sachs
Sandhoff GM2 activator deficiency |
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what are the subtypes of Niemann-Pick disease?
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Type I: A and B
Type II: C1 and C2 |
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which sphingolipid disorder is most common in Ashkenazic Jews?
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Gaucher disease
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what is the cause of Gaucher disease?
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acid beta-glucosidase deficiency
(aka glucocerebrosidase) |
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which accessory protein is required for activity of glucocerebrosidase?
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Saposin C
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what is the characteristic appearance of the cytoplasm of monocytes/macrophages affected with Gaucher?
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striated tubular structures that look like wrinkled paper
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What is the cause of Fabry disease?
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alpha-galactosidase A deficiency
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what accessory protein is required for activity of alpha-galactosidase A?
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Saposin B
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what is the predominant accumulating glycolipid in Fabry disease?
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globotriaosylceramide (Gb3)
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when do symptoms of Fabry disease manifest?
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childhood or adolescence
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what are the symptoms of Fabry disease?
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pain and parasthesias in extremities
GI disturbances cardiomyopathy progressive renal impairment angiokeratomata |
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how is Fabry disease treated?
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enzyme replacement therapy
(with alpha-galactosidase A) |
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what is the cause of Farber lipogranulomatosis?
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acid ceramidase deficiency
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what accessory protein is required for activity of acid ceramidase?
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saposin D
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what are the symptoms of classic (type I) Farber lipogranulomatosis?
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painful joint swelling
hoarse cry (laryngeal involvement) |
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what causes Krabbe disorder?
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galactosylceramidase deficiency
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what accessory protein is required for galactosylceramidase activity?
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saposin A and saposin C
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what disease is also known as infantile globoid cell leukodystrophy?
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Krabbe disorder
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what is accumulates in Krabbe disorder?
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multinucleated globoid cells in the white matter of the brain
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what is the earliest symptom of Krabbe disorder?
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exaggerated startle response
(hypersensitivity to external stimuli) |
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what is the first step to degrade GM2 gangliosides?
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complexing of GM2 to GM2 activator
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what gene codes GM2 activator?
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GM2A gene
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what are the three isozymes of beta-hexosaminidase? which one is the active one?
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HexS = aa structure
HexA = ab structure HexB = bb structure **a=alpha, b=beta** HexA is only active isozyme |
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what genes encode the alpha and beta subunit of GM2 activator?
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HEXA gene encodes alpha subunit
HEXB gene encodes beta subunit |
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a mutation in what gene causes Tay Sachs?
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HEXA gene
(alpha subunit of beta-hexosaminadase) |
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what is the insertion most common in Ashkenazic Jews (1 in 27)?
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4-base insertion into HEXA gene
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what is the disease caused by defect in GM2A?
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Tay Sachs AB Variant
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what are the symptoms of GM2 gangliosidoses?
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mild motor weakness (3-5 months)
exaggerated startle response regression of acquired motor & mental skills (6-10 months) visual difficulty (cherry-red spot in fundus) Seizures by end of first year decerebrate posturing in second year |
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what are the typical histological findings in Tay Sachs?
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large, vacuolated neurons
lysosomes with whorled appearance |
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what are the symptoms of Niemann Pick type C?
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hepatosplenomegaly
progressive ataxia dystonia dementia vertical gaze supranuclear palsy (always) |
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what is ataxia?
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loss of muscle coordination
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what is dystonia?
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sustained muscle contractions that cause twisting and abnormal posturing
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vertical supranuclear gaze palsy (VSGP)
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inability to look up with eyes
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what are Kuffer cells?
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resident hepatic macrophages
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what cells are foamy and vacuolated in Niemann-Pick Type C?
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hepatocytes
Kupffer cells |
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what is the function of Niemann-Pick type C1-like 1 (NPC1L1)?
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to help cholesterol uptake in small intestine
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where are NPC1L1 proteins located?
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in the brush border cells of the small intestine
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what does ezemitibe (the drug Zetia) bind to to interfere with cholesterol absorption?
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NPC1L1
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what are the two components of the reticuloendothelial system?
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liver
spleen |
