metabolic disorders Flashcards
(43 cards)
1
Q
describe difference between cystinosis and cystinuria
-
A
- cystinuria: renal disorder, inability to reabsorb cystine = excess cystine
- cystinosis: overflow disorder, lysosomal membrane defect causing incomplete cytie metabolism = excess cystine in body that blocks reabsorption
2
Q
true or false
IEM (inborn error of metabolism) is screened in newborn screening via tandem mass spec
A
true
3
Q
list metabolic constituents/conditions detectable by urine color
A
- homogentisic acid: black
- melanin: black
- indican: blue
- porphyrins: port red
4
Q
list abnormal metabolic constituents or conditions detected by odor
A
- PKU: mousy
- MSUD
- Isovaleric academia: sweat eet
- cystinuria: sulfur
- cystinosis: sulfur
- homocystinuria: sulfur
5
Q
list phenylalanine-tyrosine disorders
A
- phenylketonuria (PKU)
- tyrosyluria
- alkaptonuria
- melanuria
6
Q
list branched chain amino acid disorders
A
- maple syrup urine disease (MSUD)
- organic acidemias
7
Q
list tryptophan disorders
A
- indicanuria
- 5-hydroxyindoleactic acid
8
Q
list cystine disorders
A
- cysinuria
- cystinosis
- homocystinuria
9
Q
describe phenylketonuria
A
- most common
- mousy odor
- increased keto acids
- cannot convert to tyrosine
- no melanin formation (tyrosine derivative)
10
Q
how is phenylketonuria tested for
A
- blood sample
- tandem mass spec
- ingestion of milk for 24 hours then test
- bacterial inhibition = Guthrie
11
Q
list urine screening tests for penylketonuria
A
- done to monitor knwon PKU
- ferric chloride test: permanent blue/green
12
Q
describe tyrosyluria
A
- excess tyrosine
- inherited or metabolic
- transitory most common (premature infant)
- acquired = severe liver disease
13
Q
list urine testing for tyrosuyluria
A
- tyrosine and leucine crystals (liver disorder)
- ferric chloride = green fading rapidly
- nitroso-naphthol test = orange-red (non specific)
14
Q
describe melanuria
A
- increased urine melanin = dark/black
- overproliferation of melanocytes releasing melanogen ox to melinin
15
Q
UA screening tests for Melanuria
A
- ferric chloride: gray or black precipitate
- sodium nitroprusside: red
- Ehrlich: red
16
Q
describe alkaptonuria
A
- urine becomes darker andr alkaline left standing
- brown pigments deposited in body
17
Q
list urinalysis tests for alkaptonuria
A
- ferric chloride: blue
- clinitest: yellow precipitate
- alkalization: alkali to fresh = dark color
- silver nitrate: added to fresh urine = black
18
Q
list two major groups of defective metabolism of branched-chain amino acids
A
- accumulation (early degradation products)
- organic acidemias (further down)
19
Q
describe maple syrup urine disease
A
- inborn error of metabolism
- includes leucine, isoleucine and valine
- inability to metabolize keto acids = accumulation
20
Q
list three amino acids involved in maple syurp urine disease
A
- leucine
- isoleucine
- valine
21
Q
UA findings of MSU
A
- maple syrup smell
- ketone pos
22
Q
list symptoms of organic acidemias
A
- metabolic acidosis
- increased serum ammonia
- can thrive but with problems
23
Q
lst common organic acidemias
A
- isovaleric acidemia
- propionic acidemia
- methylmalonic acidemia
24
Q
true or false
there is no UA testing for organic acidemias
A
true
- only tandem mass spec
25
describe tryptophan disorders - two increasing excretions
- increased excretion of both indican and 5-HIAA
26
describe indicanuria
- abnormal intestinal reabsorption
- tryptophan converted to indole then indican
- blue urine on oxidization
27
what is associated with hartnup disease
indicanurie
- inherited metabolic disease
- no reabsorption of tryptophan
- renal tubule abnormalities
28
define cystinura
defect in renal tubular transport of amino acids
- renal disorder
29
define cystinosis
inborn error of metabolism
- overflow disorder
- nonfunctional lysosomal membranes
30
describe cystinuria
- elevated cystine in urine
- inabiility to reabsorb filtered cystine into blood
- lysine, arginine and ornithine not reabsorbed
- renal disorder
31
list UA findings of cystinuria and testing
- cystine crystals
- cystine calculi (common in children)
- cyanide nitroprusside test = purple
32
describe cystinosis
- overflow disorder
- defect in the lysosomal membrane prevents cysteine from being metabolized in the cytoplasm
- Crystal deposits in the body
- crystals cover RTE cells and prevent reabsorption ==> acquired fanocni
33
define homocystinuria
metabolic defect of methionine producing increased homocysteine
34
UA tests for homocystinuria
- screening: red cyanide nitroprusside (pos)
- confirmatory: red silver nitroprusside (pos)
35
list 3 main types of porphyrin
- uroporphyin
- coproporphyrin
- protoporphyrin
36
list two main precursors of interest in porphyrinuria
ALA and porphobilinogen
37
distinguishing characteristics of porphyrias
port wine red urine
fluorescence (purple, pink or red)
38
define glycoaminoglycans
located in connective tissue
- inherited disorder = prevents the breakdown of polysaccharide branches
39
list type of mucopolysaccharidoses
- hurlers - connective tissue in the face
- hunters
- sanfilippo's - most common
40
list testing for mucopolysaccharidoses
- CTAB
- acid-albumin
- metachromatic staining spt test
41
describe Lesch-Nyhan
- purine metabolism disorder
- uric acid crystals
- orange diaper sand
- goat
42
define melituria
presence of increased urinary sugar (any sugar)
43
describe galactosuria
inability to metabolize galactose to glucose
- glucose negative, build up of galactose
- galactosemia
