Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MedGen > Metabolism/NBS/MNT > Flashcards

Metabolism/NBS/MNT Flashcards

1
Q

what three main questions should you ask about substrates?

A

what’s the molecule?
what are we consuming to get it?
how’s it being stored?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how are excess carbs stored? what happens to them when stores are full?

A

glycogen in liver and muscle

converted to fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what happens to excess amino acids?

A

converted to glucose and fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

when does the body enter fasting?

A

about 1 hour after eating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the three processes that occur during fasting? when? what happens?

A

1) glycogenolysis (1-4 hours), glycogen -> glucose
2) gluconeogenesis (3-12 hours), AA -> glucose
3) fatty acid oxidation/ketogenesis (10+ hours), fatty acids -> ketones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the body’s main energy users?

A

brain and muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does the brain prefer as energy?

A

glucose, can use ketones in periods of starvation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What roles does the liver play in metabolism?

A

maintain blood glucose levels, produces enzymes for clotting, and facilitates the creation an recycling of bilirubin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What happens if the lysosome enzymes don’t work properly? how can these occur?

A

massive buildup/storage of material causes them to swell and burst

deficient activity of a single lysosome enzymes, failure of enzymes to localize to lysosome, defect on transport of compounds out of lysosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are some of the functions of peroxisomes?

A

produce hydrogen peroxide, play a role in beta-oxidation of VLCFAs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the common mechanisms of inborn errors of metabolism? what typically causes these?

A

toxic accumulation of subtances

reduction of normal compounds

usually single gene disorders

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the characteristics of IEMs? how can they be treated?

A

roughly 1/2 identified outside of neonatal period

most are AR (other types exist)

treat: dietary, oral tx, infusions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens in GALT deficiency?

A

missing GALT enzyme -> increased Gal-1-P -> presents symptoms of galactosemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what types of things can occur if there’s an error in a metabolic pathway?

A

shunting of accumulated substrates on other pathways, accumulation of toxic substrates/products, missing cofactor or enzyme, deficient products of missing enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what type of disease has an early onset, severe if untreated, and progressive? i.e PKU

A

acute disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what type of disease may occur later in life, can live long time w/o treatment, and progressive?

A

late-onset

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what types of mutations often cause IEMs?

A

LoF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are some of the effects of mutations causing IEMs?

A

reduce activity of an enzyme, reduce or lessen effectiveness of cofactors or activators for the enzyme, produce defective transportation of compounds in the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how can we treat IEMs?

A

limit substrate and precursors (diet/substrate reduction therapy), process toxic products through alternative pathways, supplement cofactors or provide missing enzyme, supplement products or downstream products, chaperone therapy, intrathecal therapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How might an IEM present in an infant?

A

vomiting, seizures, ataxia, lethargy, coma,

dysmorphic features

skeletal abn, poor feeding, FTT (very common)

dilated or hypertrophic cardiomyopathy, hepatosplenomegaly, jaundice, and liver dysfunction

DD, hypotonia or hypertonia, visual and auditory disturbances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How might an IEM present in an older child or adult?

A

various levels of LD,DD,ID; autism
exercise intolerance, muscle weakness (can be progressive), behavioral disturbances, ataxia, anxiety/panic attacks, seizures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what to look for/ask about in pt Hx for IEM?

A

onset of symptoms w/ change in diet and unusual dietary preference/aversion

decompensation out of proportion to what would be expected from infection

similar findings of unexplained neonatal or sudden infant death in siblings or materanl male relatives

Hx of deterioration after intial period of good health

infants and young children may have hx of recurrent episodes of vomiting, ataxia, seizures, lethargy, coma, etc.

poor feeding, FTT, DD, may not reach milestones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what’s the normal range of glucose in the blood? what level is hypo?

A

70-140 mg/dl

<50 in children
<55 in adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what can the body do if enough glucose isn’t present?

A

other food sources: FAs, ketone production and oxidation, metabolism of lactate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What should you think of if hypoglycemia is primary?

A

carb metabolism (GSD I), fat metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What should you think of if hypoglycemia is secondary?

A

disorders of protein metabolism or mito

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

how is NH4 (ammonia) typically removed from the body? what is considered elevated? what happens?

A

by the liver and excreted in urine

> 80

disrupts ATP production

28
Q

what symptoms often result from hyperammonemia?

A

neurological symptoms, significant is seen in a limited # of IEMs

29
Q

what should you suspect if you see 10-100x ammonia levels? 2-3x?

A

10-100: urea cycle defects

2-3x: mito or protein metabolism issues

30
Q

What is respiratory alkalosis? acidosis? metabolic alkalosis? acidosis?

A

1) caused by excessive loss of CO2 (hyperventilation)
2) abn CO2 retention (hypoventilation)
3) reduction of plasma H+ - most commonly from vomiting, ingestion of alkaline drugs
4) net gain of H+ or loss of bicarb -> severe diarrhea, diabetes, strenous exercise, and severe renal failure

31
Q

what is the anion gap? normal?

A

diff btwn major cations and major measured anions

less than or equal to 16*

32
Q

what can cause an increase in plasma lactate?

A

increased pyruvate production or decreased pyruvate consumption/oxidation

33
Q

what should you expect if hyperlacticacidemia is primary?

A

carb metabolism or mito disease

34
Q

what should you expect if hyperlacticacidemia is secondary?

A

protein or fat metabolism

35
Q

how does ketoacidosis occur?

A

defects in keton utilization or increased ketone production - typically secondary

36
Q

What does CK indicate? what types of conditions can it point to?

A

muscle breakdown or injury

mito, some LSDs

37
Q

tea colored urine can be a sign of:

A

rhabdomyolysis

38
Q

what purpose do carnitines serve?

A

shuffle fatty acids across mito membrane to undergo beta-oxidation

39
Q

If you have galactosemia, you are deficient in: _____. Inheritance? enzyme function?

A

GALT enzyme
Autosomal recessive

5% or less enzyme function

40
Q

what condition is related to classic galactosemia, more frequent, and is known for it Duarte variant? level of enzyme activity? symptoms?

A

partial transferase deficiency

10-50% enzyme activity

usually asymptomatic

41
Q

How is galactosemia detected with NBS? Confirmation? Is there mutation sequencing?

A

abn high level so fGal-1-P

confirmed with GALT

classic panel testing looks for 6 mutations (seq also available)

42
Q

what are some of the features of galactosemia?

A

feeding problems, vomiting, diarrhea, FTT, hypoglycemia, liver failure/jaundica, bleeding, sepsis, females @ increase risk foo premature ovarian failure, DD/ID, cataracts, delayed growth, speech apraxia

43
Q

how can we treat galactosemia?

A

dietary intervatnion
lactose-free formula
calcium supplementation

44
Q

the types of Glycogen storage disease can be broken into 2 groups:

A

hepatic (GSD1 and III) - enlarged liver

muscular (GSD II and V)

45
Q

Classic PKU and maternal PKU are both examples of _______ deficiency. This is an example of a defect in _________ metabolism.

A

PAH, protein

46
Q

untreated classic PKU can present with:

A

seizures, severe or profound ID, microcephaly, behavioral problems, very light skin and hair

47
Q

those with PKU may have _______ smelling urine.

A

mousy

48
Q

how can we treat PAH deficiency? what other amino acid becomes essential (needed from diet)?

A 
PKU diet (limit Phe)
avoid meat, fish, eggs (high protein)
use Phe-free formula as supplement

tyrosine because the body cannot make it from Phe

49
Q

What is tthe purpose of the urea cycle? how might you detect UC defects?

A

rid body of waste nitrogen

elevated levels of ammonia in blood

50
Q

how can we treat UC defects?

A

restrict substrate or precursor

provide or supp. deficient enzyme

increase alt pathway use

supplement products

51
Q

Maple syrup urine disease, isovaleric aciduria, 3MCC deficiency, MMA, Canavan disease, and biotinidase deficiency are all examples of:

A

organic acidurias

52
Q

How are fatty acids released in the body?

A

lipoprotein lipase and hepatic lipase cleaving triglycerides

53
Q

VLCAD, LCHAD, TFP, MCAD, SCAD, SCHAD are all examples of:

A

Fatty acid oxidation defects

54
Q

If you are deficient in MCAD enzyme and have a 985A>G, K304E mutation then you have:

A

MCAD

55
Q

what anaylte trends are seen in MCAD?

A

low plasma carnitine, high medium-chain acylcarnitines

56
Q

how can we treat MCAD?

A

modify infant diet (30% fats)
supplement carnitine as needed
avoid prolonged fasts

57
Q

What is the clinical relevance of fatty acid oxidation defects?

A

oftn cause infant or childhood death following minor illness with fasting

affecting multiple sibs in a family

tx available and highly effective for some

58
Q

what condition set the standard for NBS?

A

PKU

59
Q

what are the criteria for conditions on NBS?

A

severe consequences if not treated soon after birth

simple and inexpensive biochemical test

treatable and is available and effective

60
Q

when do we screen infants for IEMs? why?

core panel screens for how many conditions?

A

24-48 hours after birth (at least one meal)

don’t want to screen in a fasting state

35+

61
Q

Tandem Mass Spec for NBS has a relatively high FP rate…why?

A

so we don’t miss as many as possible

62
Q

what are the goals of medical nutrition therapy?

A

promote healthy brain function and healthy physical growth/development

63
Q

whats’ the major energy difference between simple and complex carbs?

A

simple -> quick source

complex -> longer to break down

64
Q

what’s the goal for MNT for carb metabolism defects?

A

avoid prolonged fasting, restrict offending sugar, prevent hypoglycemia

65
Q

In GSD Type 1a, pts can store glycogen but not break it down, how might we treat this with MNT?

A

high protein, low carb

use sucrose and lactose free formula

consume complex carbs (cornstarch)

use nighttime feedings to prevent fasting

66
Q

generally those with protein metabolism disorders are not allowed: … what are they allowed?

A

most high protein foods

high carb food in high amounts

67
Q

What fatty acids must come our diets?

A

Omega 6 and 3

MedGen (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions