In born errors of metabolism 1 Flashcards
- List the key laboratory studies that should be obtained in the patient with hypoglycemia that will help elucidate the underlying cause.
c peptide, insulin, counter regulatory, ketones, lactate, carnitine
G 6 Phosphatase deficiency
Hypoglycemic, low insulin, large liver, high lactate, high triglycerides. early presentation, short stature, doll phase
Tx with constant glucose
can build glycogen cant get it out, so it goes to pyruvate and lactate–> lactic acidosis
whipples triad
for hypoglycemia
classic neuro or autonomic symptoms
BG
branching enzyme deficiency
abnormal glycogen, liver damage–> cirrhosis by age 4-6
hepatosplenomegaly, failure to thrive
abnormal glycogen accumulated in muscle and heart (cardiomyopathy)
evidence of issues during exercise
Glycogen synthase deficiency
hyperglycemia after a meal, followed by hypoglycemia later.
increased lactate, and severe ketotic hypoglycemia
normal liver
Tx- high protein diet, low glycemic index (corn starch)
glycogen phosporylase
1
Glycogen phosphorylase kinase
1
debranching enzyme
hypoglycemia, big liver, growth retardation
normal uric acid and lactate
elevation of liver enzymes due to damage
fasting ketosis
milder presnetation on hypoglycemia
Tx- low glycemic index (corn starch), keep blood sugar above 70
pyruvate carboxylase deficiency
issue with gluconeogenesis probably lethal
PepCK deficiency
issue with gluconeogenesis probably lethal
Fructose-1,6-bisphosphatase deficiency
high lactate, metabolic acidosis, kussmaul bleathing
hypoglycemia, late and mild
ketones are present
Tx- give glucose, avoid long fasting
Herditary fructose intolerance
AR, absesne of aldolase B leads to intracellular trapping of fructose 1-P. toxic to liver kidney brain
happens when fruit is introduced
nausea vomiting sweating hypoglycemia
Galactosemia
UDP transferase, cataracts, hepatospenomegaly and cirrhosis
Lactose free diet
galactosemia, galactosuria, nausea vomiting and jaundice
galactokinase deficiency
cant phosphorylate galactose
causes galactosemia and galactosuria,
inborn errors of fat metabolism
fasting hypoglycemia with low ketones, no big liver(liver failure-cant get fuel) hypotonia
deprive gluconeogenesis of a fuel source
makes tissue obligate glucose users
exercise induced rhabdo
carnitine issues
1
acyl coa dehydrogenase deficiency
AR can be specific to chain length medium chain most common hypoglycemia, Urine organic acids (cant utilize them acyl coa derivatives in blood
muscle and heart dysfucntion
hypoglycemia
no ketones, fatty liver and hepatomegaly (less dreamatic)
Tx- avoid fasting, carb rich diet
HMG-CO synthase or Lyase
no ketones (milder)
counter regulatory hormone issues
hypopituitarism, growth hormone def, ACTH or cortisol def. (addisons) beta blockers
defects in insulin suppression
congenital hyperinsulinism
infant of a diabetic mother
iatrogenic (innapropriate insulin)
insulinoma
ketotic hypoglycemia
one of the most common cuases of hypoglycemia in childhood
Dx of exclusion
lack of substrates for gluconeogenesis, hypoglycemia after fasting, sponataneously goes away as they age
