IEM & general information of healthy infants Flashcards
def. inborn error and IEM
Definition: inborn error
o Gene mutations, usually caused by recessive gene
o Dysregulation in the synthesize of enzymes, coenzymes and transporters necessary for the metabolism of carb, lipids and amino acids
Definition: metabolism
o Accumulation of toxic metabolites
o Deficiency in essential metabolites
T/F IBE can be detected at early age
F
IEM may start to present at any age with wide range of severity but mostly manifest around the newborn period
why do newborn error screening?
there was high incidence of metal retardation before screening; to catch the problem before the damage becomes accumulated
list down 5/8 common syntoms
- overwhelming illness in the new born period
- cardiomyopathy
- seizure
- recurrent vomiting
- developmental delay/mental retardation
- neuropsychiatric symptoms
- poor growth/failure to thrive
- loss of previously acquired skills
newborn error screening: test
First test: urinary phenyl pyruvic acid for PKU
Dry blood spots: collect 24-48 hours after birth for metabolic intermediaries detection
• Canada: 38 conditions
6 guidelines for IE
- In differential diagnosis of sepsis, anoxic encephalopathy or toxic ingestion
- Persist symptoms
- Typical common laboratory test fail to determine a definitive diagnosis
- Can present as either acute illness or as chronic disease/ recurrent and progressive/ at any age
- Can occur in the context of negative family Hx or genetic/metabolic disorder (recessive gene mutation)
- Neonatal death from undetermined causes
list down the first 3 most common IEM conditions
PKU: phenyl ketonuria
MMA: Methylmalonic acidemia
galactosemia
what is the different between Mitochondrial disorder and other common IEMs?
it is from X chromosome only: x-linked mtDNA mutations.
Most IEMs are autosomally recessive
Most commonly absent enzyme: PKU
PAH: phenylalanine hydroxylase
Most commonly absent enzyme: MMA
Methyl malonyl
4 Modals for nutrition management
A: restrict substrate
B:supplement product
C:supplement co-factor to increase residual enzyme activity
D: ajunct therapies—remove abnormal metabolites
what are the 4 difficulties in terms of nutrition management?
- single or multiple nutrition restriction
- risk of nutrition deficiency
- specific supplements, especially regarding essential AAs
- Appropriate growth = the achievement of metabolic balance, which is hard
what is the priority in nutrition management? how to monitor?
- NRG adequacy
- proteie-energy ratio
if someone has IE of protein metabolism, how would you increase total NRG?
choose low-protein breads and pasta for NRG adequacy without adding more protein to the foods
AAs mix vs the source of whole protein
prefer to whole protein (more efficient in some disorder)
why protein balance is very important?
- Growth will be limited by the AA in shortest or inadequate nitrogen supply in the diet.
dietary fat is a good source to meet NRG requirement except:
IE regarding fat oxidation
Four 4 steps in terms of overall PKU management
- Reduce blood phe under 360 umol/L
- Add little by little intact protein to cover phe needs
- Supplement with large neutral AA to compete for he transporter
- Inadequate protein = Assess deficiency?
How to reduce blood phe under 360 umol/L
Fully restrict all protein sources that contain Phe until below 360 umol/L
Acute management of PKU for infants
- Reduce blood phe < 360 umol/L
- Phe-free formulas
- Can reintroduce standard formula or breastmilk in controlled amounts (the level of phe vary)
chronic management of PKU for infants
- Manintain blood phe at range 120-360 umol/L
- Supporting normal growth and development
- Preventing nutrient deficiencies
what is the main end goal of nutrition therapy for IEM
nutrition adequacy for growth (follow the growth curve)
what is Galactosemia
: high accumulation of galactose-1-P, galactose, galactitol and galactonate due to deficiency of GALT. Sometimes, other enzyme deficiencies may exist as well, like GALK and GALE.
the most common complication
jaundice because of liver damage
list 4/6 common consequence of galactosemia
o Most common complication--- jaundice because of liver damage o Anorexia o Potential risk of sepsis o Ultimately fatal o Enlarged liver o Kidney damage
overall nutrition management of galactosemia
restriction of galactose through drinking metabolized milk.
the concern if no restriction of galactose intake
Usual unmetabolized milk will cause the galactose accumulation and ultimately damage the liver, eyes, kidney and brain
Acute management: galactosemia
- Soy-based medical food (forbid dairy components)
- PN can be an option after EN or PO
- Medication: avoid the one containing lactose fillers
Chronic management: galactosemia
- Dairy elimination
- NO Breast feeding
- Rec to continue monitor Vit-D status for bone health
- Education to parents: label reading
- F/V is okay (negligible amounts of Gal)
list 4 items that contain galactose/lactose but ppl commonly don’t realize
butter, organ meats, fermented soy products and soy sauce, meat by-products, milk chocolate
• Breast-fed babies usually feed ? times or more per day
averagely 8 or more
for commercial formula: 6 or more
how do you know it is feeding enough
Urine, Stools, Weight
Baby seems full after drinking
list 5 signs that the baby is not drinking enough
- baby is very drowsy and difficult to wake for feeding
- urine is dark yellow or very little (e.g., more than 6 hours between wet diaper)
- there are orange stains in the urine after the first two days
- stools still contain meconium after the 5th day
- fewer than one bowel movment per 24 hours between the age of 5 days to 4 weeks
when to report APGAR score
• Reported at least at 1 minute and 5 minutes after birth in all infants
APGAR: the range of normal
7-10
what is 0 APGAR score for R?
no crying
heart rate: 2 APGAR SCORE
HR > 100/min
