Metabolism Flashcards
Metabolic acidosis with normal NH4 (2 bigs)
- MSUD
2. Organic acidemias
Three disorders with elevated NH4 and metabolic acidosis?
- Propionic Acidemia
- Methylmalonic Acidemia
- Fatty acid oxidation defects
Normal ABG and metabolic looking kid, think what if also w/ high NH4?
Urea Cycle disorder
Metabolic kid w/ normal ABG and normal NH4? (3)
- aminoacidopathy
- galactosemia
- non-ketotic hyperglycinemia
acidotic newborn, ketotic, high NH4
Next diagnostic step and dx?
Check urine organic acid levels: suspect organic acidemia
blood issues you can see with organic acidemia?
low plt and low WBC
lethargy, poor feeding, seizure, high incidence of infections, sweaty feet odor
Dx and tx?
Isovaleric Acidemia
Tx: protein restriction
metabolic d/o with falling down, decr appetite, delayed milestones
organic acidemia
no reducing substances in urine
ketones in urine
normal serum AAs
hepatomegaly, hypoglycemia
Fatty acid metab d/o
Dx of fatty acid metab?
plasma acylcarnitine profile
clue to fatty acid metab d/o w/ timing?
OCcurs w/ fasting, think kid w/ recent decr PO intake
Hyperammonemia w/o acidosis?
Urea cycle defect
may have respiratory alkalosis and lactic acidosis
sx free period, then hypotonia/coma
urea cycle defect
Tx of acute w/ urea cycle defect?
reduce protein intake, incr glucose intake, prn dialysis
metabolic d/o w/ propensity toward gram neg (E coli) infx?
Galactosemia
kid who seizes so avoids sweets
inherited fructose intolerance
positive reducing substances in urine?
galactosemia
islet cell hyperplasia in what syndrome?
Beckwith Wiedemann
hypoglycemia and hepatomegaly?
think galactosemia
drug of choice for refractory hypoglycemia in infant?
diazoxide: decreases insulin secretion, stimulates cortisol release
A good next test for infants w/ hypoglycemia, sz, hepatomegaly, FTT?
urine ketones and reducing substances
lactic acidosis w/ high anion gap, rash, alopecia, neuro signs?
Dx and Tx?
Biotinidase deficiency: (BIO: Bald, Itchy rash, Out cold coma)
Tx w/ biotin supplementation
hypertonic infant w/ tachypnea and shallow breathing, and lethargy in first week of life?
MSUD
amino acids that are elevated in MSUD?
VIAL: valine, isoleucine, alloisoleucine, leucine
homogentisic acid in urine in what disorder?
tx?
Alcaptonuria: dark diaper
tx w/ low phenylalanine and tyrosine
dislocated lens, skeletal abnormality, cognitive issues
Dx?
Tx? (2)
homocystinuria: confirm homocystein in urine
Tx: pyridoxine and then high cystine low methionine diet
when should PKU screening be done
48-72 hrs after protein feed
formula for PKU
lofenalac: low phenylalanine formula
complication of PKU tx
what do they need supplementation w/?
overtx: lethargy, rash, diarrhea - phenylalanine def
Need tyrosine: becomes essential AA
incr heparan sulfate in urine
San Filippo (MPS type III)
adenosine deaminase deficiency
lesch nyhan
doll like face, hypoglycemia, distended abdomen (large liver)
Dx and cause
Glycogen Storage Disease type 1
-defect in glucose-6-phosphatase
lab findings in glycogen storage disease type 1
hypoglycemia,
High: lactic acid, uric acid, TG, cholesterol
large tongue, large heart, respiratory failure,
floppy but hard muscles
Pompe disease
defect in familial hypercholesterolemia
LDL receptor deficiency
thin and long newborn, fat tissue resistant to insulin
congenital lipodystrophy
skin nodules, painful joints in first week of life
cherry red spot in retina
Farber’s disease (think Farmer picking cherries)
large liver and spleen, calcified adrenal gland, fatty deposits
Dx?
Cause?
lab findings?
Wolman disease
defective lipoprotein metab
TG and cholesterol esters in body tissue but normal plasma TG/cholesterol levels
calcified enlarged adrenals
Wolman dz
low serum copper and low serum ceruloplasmin, but HIGH Tissue copper
menkes
true dx of Wilsons
liver bx
orange colored skin lesions, eye opacity, kidney/heart/brain issue
Fabry disease (Lysosal lipid storage dz)
What is krabbe?
demyelination w/ leukodystrophy, progressive neuro decline, death by 2y
cherry red spot, CNS deterioration, HSM
Niemann Pick
another thing to think of if positive PKU screen
BH4 def (coenyme tetrahydrobiopterin), also high phenylalanine levels can be transient, so repeat
thin body habitus, scoliosis, posterior dislocated lens, cognitive impairment
homocystinuria
tx of homocystinuria
pyridoxine
type of lens dislocation in Marfan
anterior
risk of what in homocystinuria?
PE, thrombi
can treat some urea cycle defects w/ what?
arginine
can treat some organic acidemias with what?
biotin
methylmalonic acid responds to what?
B12
Sjogren-Larsson syndrome
- what is it
- clinical presentation
- dx?
inborn error of lipid metab
“MRCP”, seizures, photophobia, vision issues / dots on the retina, ichthyosis is key
Dx: fatty alcohol: NAD oxidoreductase in cultured skin fibroblasts
predisposition to severe hypoglycemia, coma
lab shows hypoglycemia without ketonuria
Acylcarnitine profile abnormal!
what is the primary defect and treatment?
MCAD - medium chain acyl-coA dehydrogenase def
tx w/ freq feeding and carnitine
treatment of MSUD?
restrict branch-chain amino acids / protein
Give thiamine B1
Treatment of Non-ketotic hyperglycinemia
benzoate, valium, dextromethorphan
Treatment of methylmalonic aciduria?
B12
Treatment of homocystinuria?
Betaine, Folate, ASA
Glucocerebrosidase def?
Gaucher disease
Three types of Gaucher dz?
1: mild
2: acute neuronopathic
3: chronic neuronopathic
defect in Gauchet’s
glucocerebrosidase deficiency
