Metabolism Disorders Flashcards
Hemolytic anemia
usually occurs in patients with G6PD deficiency when cells are under oxidative stress.
What agents cause oxidative stress?
infections
fava beans
drugs such as antimalarials, sulfa antibiotics, and anti-pyretics (reduce fever).
intense activity
insulinoma
causes significantly higher levels of insulin in the blood, hypoglycemia
VonGierke GSDI
mutation of glucose-6-phosphatase, which normally converts G6P into glucose.
Does not affect glycogen synthesis because glycogen synthesis can start with G6P.
It does impair the liver’s ability to release glucose from stored glycogen and impairs gluconeogenesis, resulting in severe hypoglycemia, hepatomegaly, and lactic acidosis (due to excess pyruvate that cannot be turned back into glucose.)
Pompe GSD II
mutation of lysosomal a1,4-glucosidase (which normally breaks down glycogen.)
Inclusion bodies with glycogen.
Cardiomegaly, weakness, death due to accumulation of glycogen in the lysosome.
Cori GSD III
Mutation in debranching enzyme (breaks down glycogen).
glycogen has shorter outer branches due to arrested degradation. Without glycogen debranching enzymes to further convert limit dextrinosis into glucose, they accumulate in the cytoplasm.
mild hypoglycemia, hepatomegaly.
Anderson GSD IV
Mutation of branching enzyme.
Glycogen has long chains with few branches. This abnormal glycogen accumulates in the cells.
Causes cirrhosis, hypoglycemia, and death.
McCardle GSD V
mutation of muscle glycogen phosphorylase, which is involved in the breakdown of glycogen to glucose-1-phosphate in muscle cells.
glycogen is normal
causes muscle cramps and weakness in teens.
Hers GSD VI
Mutation of liver glycogen phosphorylase, which catalyzes the rate-limiting step in glycogenolysis.
glycogen is normal.
Causes mild hypoglycemia, cirrhosis.
