Inborn Errors of Metabolism Handout Flashcards
MCAD ethnic
Northern european
MCAD clinical presentation
Develop normally until prolonged fast (often with illness)
Develop hypoketotic hypoglycemia
Presents with altered mental status and lethargy
Diagnosis of MCAD
Screening
Lab eval will reveal non-ketotic hypoglycemia
C6-C10 acylcarnitines
Management of MCAD
Avoid fasting
VLCAD def
Similar to MCAD with fat deposition into organs
Hepatomegaly and liver dysfunction, cardiomyopathy, muscle weakness
C14-C16 acylcarnitines
Restrict dietary fats AND avoid fasting…supplement with medium chain
Clinical manifestations of organic acid disorders
Lethargy, vomiting, and failure to thrive
As progession, hypotonia, seizures, and coma
Metabolic acidosis with high anion gap and ketosis
Could also have elevated lactate, hyperammonemia, and/or hypoglycemia
Diagnosis of organic acid disorders
Most by screening but could develop after
Propionic acidemia
Defect in propionyl-CoA carboxylase leads to defect in Ile, Val, Met, and Thr metabolism
Measure urine for propionic acid
Stop all protein intake and administer dextrose
Methylmalonic acidemia
Methylmalonic acid AND propionic acid in the urine
Adminster Dextrose and stop protein
Vitamin B12 as supplemnt
PKU clinical manifestation
Microcephaly and developmental delay
Adults may have risk of mood disorders or cog dysfunction
PKU diagnosis
Usually screening…see increase in Phe
Management of PKU
Administer BH4 (cofactor)…limit Phe intake
MSUD clinical
Lethargy and irritability, seizures and poor feeding…hypertonicity
Diagnosis of MSUD
Measurement of plasma AAs show elevated Leu, Ile, and Val (alo alloisoleucine)
typically screened but could develop after
Managment of MSUD
Stop all protein intake and administer dextrose
Long term is to administer thiamine and limit
Tyrosinemia 1 clinical
Failure to thirive and hepatomegaly
Kidney toxicity from renal tubular dysfunction presenting as renal tubular acidosis and hypophosphatemia
Diagnosis of tyrosinemia 1
Typically screened
Elevated tyrosine and methionine
Also elevated succinylacetone
Managment of tyrosinemia 1
Reduce met, tyr, and phe
Nitisinone inhibits a dioxygenase whcih decreases generation of toxic fumarylacetoacetate
GSD type 1 enzyme, clinical, labs
G-6-pase
Hepatomegaly with failure to thrive
Severe hypoglycemia
GSD type 3 enzyme, clinical, labs
Debranching enzyme
Hepatomegalym, failure to thrive, muscle weakness, hypotonia
Mild hypoglycemia
GSD type 4 enzyme clinical labs
Branching enzyme
Liver failure
Hypoglycemia occurs late
GSD Type 6 enzyme clinical labs
Hepatic phosphorylase
Hepatomaegaly and failure to thrive
Mild hypoglycemia
Diagnosis of GSDs
Look for hypoglycemia with hypertrigluceridemia, lactic acidosis and hepatomegaly…DNA testing to confirm
Management of GSDs
Maintain glucose levels to prevent hypglycemia…uncooked corn starch
Anderson has no therapy and need liver transplant
Galactosemia inheritance
Auto rec
Galactosemia clincal
After breast feeding Jaundice, poor feeding, and vomiting Hepatomegaly Cataracts Hyperbilirubinemia, abnormal liver function, reducing substances in urine Ketones absent
Galactosemia diagnosis
Newborn screening but may develop after weeks
MEasure GALT activity
Management of galactosemia
Eliminate galactose…soy-based formulas
Hereditary fructose intolerance clinical
Recurrent vomiting and poor feeding after intor of fructose or sucrose into diet
Lethargy and seizures
Hepatomegaly, jaundice and renal dysfunction
Hypoglycemia, hyperuricemia, metabolic acidosis and/or lactic acidosis reducing substances in urine …ketones absent or normal
Diangosis of hereditary fructose intolernace
DNA testing
Managment of hereditary fructose intolerance
Eliminate fructose from diet
