inborn errors of metabolism Flashcards
deficiency in pku
phenylalanine transferase (cant convert phe to tyrosine); mild problem with BH4
lab results for pku
UOA: inc phenylketones
PAA: inc Phe, low tyrosine
due to low tyrosine-
1. low neurotransmitters: dopamine, norepinephrine, and adrenaline
2. fair skin (Tyr is a precursor of the skin pigment melanin)
PKU as teratogen (features)
dysmorphic features, microcephaly, IUGR, congenital heart
clinical features in infant with PKU
fair skin
eczematoid rash
mousy/musty odor
treatment of PKU
restrict phe, BH4 supplement
first test for change in mental status
blood glucose
condition could falsely elevate NH4
use torniquet, prolonged process in lab (result in 1 hr), no ice
how to collect NH4
free flow, ice, process within 1 hr
Condition with elevated lactate:pyruvate
mitochondrial d/o
What presents with elevated plasma AA
aminoacidopathies, urea cycle, organic acedemia
What presents with abnormal urine organic acid
AA, FAOD, organic acid
Mode of inheritance of aminoacidopathies
autosomal recessive
Labs suggestive urea cycle do
AbN PAA, elevated NH4, respiratory alkalosis
Labs suggestive Organic Acids
Abn PAA, metabolic acidosis, AbN UOAs
Deficiency in MSUD
branched chain alpha ketoacid dehydrogenase
What are the Branched-chain AA
Isoleucine, valine, LEUCINE
MSUD and ethnic group
Old order Mennonites
presentation MSUD
diminished arousal
poor feeding
hypertonia
coma
death
maple syrup smell
which branched-chain AA causes Sx in MSUD
Leucine (neurotoxic and osmotic effect)
Acute mgt of MSUD
high dextrose isotonic Iv and lipids; serum Na high normal
long term mgt for MSUD
diet, liver transplant
deficiency in homocystinuria
deficiency in cystathionine beta synthetase
labs finding homocystinuria
elevated homocysteine and methionine in blood, urine, NBS, plasma AA
clincal features of homocystinuria
intellectual disability
tall stature
osteoporosis
recurrent thrombosis
ectopia lentis (lens dislocation- downwards)
