Glycogen Storage and Lipid Disorders

Question 1

I - von Gierke

Answer 1

glucose-6-phosphatase def

severe hypoglycemia (gluconeogenesis blocked also!!)
lactic acidosis
hepatomegaly
hyperlipidemia (inc glucagon - inc glucagon)
protruded abdomen, emaciated extremities

Question 2

II - Pompe

Answer 2

Lysosomal alpha-1,4 glucosidase def

cardiomegaly
muscle weakness
death in 2 years

Question 3

III - Cori

Answer 3

glycogen DEbranching enzyme def

mild hypoglycemia
liver enlargment
limit dextrinosis

Question 4

IV - Andersen

Answer 4

Branching enzyme def

infantile hypotonia
cirrhosis
death in 2 yrs

Question 5

V - McArdle

Answer 5

muscle glycogen phosphorylase def

muscle cramps and weakness with exercise
myoglobinuria
NO hypoglycemia or hyperlipidemia
glycogen accum on muscle biopsy (sugar stains PAS positive) - diff with CAT/CPT def

Question 6

VI - Hers

Answer 6

hepatic glycogen phosphorylase def

MILD fasting hypoglycemia (gluconeogen unaffected)
hepatomegaly
cirrhosis

Question 7

Abetalipoproteinemia

Answer 7

apo-B100 apo-B48 def (auto rec)

accum of lipid, chol within cholesterol due to inabilityto export chylomicrons

failure to thrive
steatorhea
acanthocytosis
ataxia

Question 8

I Primary hyperlipidemia

Answer 8

LPL or apoC-II def (auto rec)
elevated chylomicrons AND VLDLs

red-orange eruptive xanthomas
fatty liver
acute panc

Question 9

IIa Primary hypercholesterolemia

Answer 9

LDL receptor def (auto dom)
elevated serum cholesterol

MI at very early age!!! like 5 if homozygous
inc risk atherosclerosis, coronary artery disease
xanthomas on achilles tendon
tuberous xanthomas on elbows
xanthelasmas
corneal arcus

Question 10

Myopathic CAT/CPT def

Answer 10

presents like McArdles BUT
muscle aches and weakness happen after prolonged fasting!
still provocated by exercise
lipid accum on muscle biopsy (stain oil red O, sudan black)