Metabolic disorders

Question 1

Overflow vs renal disorders

Answer 1

Overflow: disruption of pathway. Inborn error of metabolism
Renal disorder: malfunction in tubular reabsorption mechanism

Question 2

Abnormal metabolic constituents
Color

Answer 2

Homogentistic acid
Melanin
Indican
porphyrins

Question 3

abnormal metabolic constituents
Odor

Answer 3

Phenylketonuria
MSUD
isovaleric academia
cystinuria
cystinosis
homocystinuria

Question 4

Abnormal metabolic constituents
crystals

Answer 4

cystine
leucine
tyrosine
lesch-nyhan disease (uric acid)

Question 5

Amino acid disorders

Answer 5

Phenylalanine Tyrosine disorders
Branch chain amino acid disorder
tryptophan disorders
cystine disorders

Question 6

Phenylketonuria

Answer 6

Mousy odor urine
Increase keto acids in urine
can’t code for phenylalanine hydroxylase
Decrease in melanin

Question 7

Phenylketonuria treatment

Answer 7

newborns/babies: specialized formula
No food with phenylalanine/aspartame
can alter diet slightly with age

Question 8

Phenylketonuria blood testing

Answer 8

Blood is tested for phenylalanine
screen for PKU
Detectable after drinking milk for 24 hours
Guthrie test

Question 9

Phenylalanine Urine testing

Answer 9

Follow up procedure
screening for known PKU to monitor
ferric chloride test: permanent blue-green color

Question 10

Tyrosyluria

Answer 10

excess tyrosine
most common: transitory in premature infants
Insufficient liver development
or live doesn’t make enzymes

Question 11

Tyrosyluria urine testing

Answer 11

tyrosine and leucine crystals (if liver disorder)
ferric chloride test (green fades rapidly)
Nitroso napthol: orange color, non-specific

Question 12

Melanuria

Answer 12

Increased melanin -> dark urine
after exposure to air
overprolifertion of melanocytes

Question 13

Melanuria condition

Answer 13

Malignant melanoma

Question 14

Melanuria tests

Answer 14

Ferric chloride (grey or black precipitate)
Sodium nitroprusside (red color)
Ehrlich’s reagent (red color)

Question 15

alkaptonuria

Answer 15

Alkali lover
darker after standing at room temp
homogenistic acid oxydase missing

Question 16

alkaptonuria condition

Answer 16

Homogenistic acid accumulates
children: brown, black stained diapers
Adults: brown pigments in body tissues, arthritis

Question 17

alkaptonuria testing

Answer 17

Ferric chloride (blue)
clinitest: yellow precipitate
Alkali additive to fresh urine -> dark color

Question 18

Branch chained amino acid (BCAA)

Answer 18

Type 1: Accumulation Early break down products (MSUD)
Type 2: Organic acidemia (acids made further in pathway

Question 19

MSUD

Answer 19

Inborn error of metabolism
Inability to metabolize keto acids
Leucine, isoleucine, valine
keto acids accumulate in blood/urine

Question 20

MSUD condition

Answer 20

Failure to thrive 1 wk after birth
UA findings: sweet odor, ketone +
Testing: MS/MS, DNPH (yellow precip), AA chromotography

Question 21

Organic acidemias

Answer 21

Symptoms: ketonuria, increase serum ammonia
Disorders: isovaleric acidemia, propionic acidemia
Testing: no UA test

Question 22

Tryptophan disorders

Answer 22

Indican
5-HIAA

Question 23

Indicanuria

Answer 23

Increased tryptophan conversion to indole
Hartnup disease
indole converted to indican -> blood -> urine

Question 24

Indicanuria indications

Answer 24

Indican oxidizes to blue
Blue diaper syndrome

Question 25

Hartnup disease

Answer 25

Inherited metabolic disease abnormalities in renal tubes (Fanconi's) dry red scaley rash muscular incoordination

Question 26

Cystine disorders

Answer 26

Cystinuria: transport of amino acids Cystinosis: error of metabolism

Question 27

Cystinuria

Answer 27

Cystine in urine renal disorder inability of tubuals to reabsorb cyctine

Question 28

cystinuria findings

Answer 28

Cystine crystals cystine kidney stones (most common in kids) cyanide-nitroprusside test: red-purple color

Question 29

Cystinosis

Answer 29

Overflow disorder incomplete metabolism of cystine defect in lysosomal membrane cystine deposits in body (cornea)

Question 30

cystinosis findings

Answer 30

polyuria aminoaciduria

Question 31

homocystinuria

Answer 31

increased homocystine failure to thrive, mental deficits, death

Question 32

homocystinuria findings

Answer 32

screening: pos cyanide-nitroprusside: red Confirm: silver-nitroprusside: red

Question 33

Porphyrin disorders screening

Answer 33

Ehrlich's reaction/Howesch test fluorescence: 550-600 nm range (extract w/ glacial acetic acid, blue = negative, purple,pink,red = pos)

Question 34

Hurler's syndrome

Answer 34

Mucopolysacchride disorder Gargoyalism usually fatal in childhood

Question 35

Hunter's syndrome

Answer 35

Mucopolysacchride disorder skeletal deformaty usually fatal in childhood

Question 36

Sanfilippo's syndrome

Answer 36

mucopolysaccharide disorder mental deficiencies most common, least detrimental

Question 37

mucopolysacchride screening tests

Answer 37

CTAB (white turbidity) Acid-albumin turbidity (white turbidity) metachromic staining (blue spot)

Question 38

Lesch-Nyhan disease

Answer 38

failure to inherit, causing large excretion of uric acid crystals

Question 39

Lesch-Nyhan symptoms

Answer 39

Gout, self destruction, renal stones, mental dysfunction Orange particles in diapers

Question 40

Carbohydrate disorders

Answer 40

Melituria: increased urinary sugar inherited disorder

Question 41

galactosuria

Answer 41

Major concern can't convert galactose to glucose GALT or G-1-PUT enzyme

Question 42

Galactosemia

Answer 42

Toxic intermediate conversion products Failure to thrive liver disorder cataracts

Question 43

galactosemia testing

Answer 43

Clinitest (not done anymore) positive while strip test negative treat w/ removal of lactose from diet