Glycogen Storage Diseases

Question 1

Glucose-6-phosphatase deficiency Type I

Answer 1

Von Gierke Disease

Last enzyme of gluconeogenesis

Question 2

Increased glycogen in
liver
kidney
intestines

Fasting hypoglycemia and massive hepatomegaly
Elevated lactate, uric acid, cholesterol and TAG

Renal complications

Slow growth, diarrhea, bleeding disorders, electrolyte abnormalities

Hypotonia and gout

Answer 2

Von Gierke Disease Type I

Question 3

Diagnosis of Glucose-6-Phosphatase Von Gierke Disease:

Answer 3

Administer epinephrine, glucagon, galactose, fructose or glycerol and it doesn’t provoke a normal hyperglycemic response

DNA testing
Enzyme measurement

Question 4

Von Gierke Disease Glucose-6-phosphatase deficiency on liver biopsy will show

Answer 4

glycogen accumulation in cells

Question 5

Treatment for Von Gierke Disease Glucose-6-phosphatase deficiency:

Answer 5

Avoid fasting

Maintain normal fasting glucose levels

Nocturnal intragastric or frequent high
carbohydrate meals until 2 years of age

intragastric feeding of uncooked cornstarch

In refractory disease, Liver transplant

Question 6

Autosomal recessive

Deficiency of muscle glycogen phosphorylase (myophosphorylase)

Answer 6

McArdle Disease

Type V

Question 7

Inherited disorder of glycogen metabolism characterized by

deposition of glycogen in skeletal muscle SUBSARCOLEMMA

Temporary weakness and cramping of skeletal muscles during or after exercise since they can’t utilize glycogen

Answer 7

McArdle Disease Myophosphorylase deficiency

Question 8

No rise in blood lactate levels during exercise

Asymptomatic in infancy

Myoglobinuria, serum CK levels always elevated

If they work out long enough, they utilize fatty acids at 25-30 mins

Answer 8

McArdle Disease Myophosphorylase Deficiency

Question 9

McArdle Myophosphorylase Deficiency diagnostic

Answer 9

Muscle biopsy assay shows myophosphorylase enzyme deficiency

Myoglobinura, increased serum CK

Question 10

Muddy brown cast

can cause

Answer 10

Myoglobin in urine

Renal tubular acidosis because myoglobin is an acid

Question 11

McArdle Myophosphorylase Deficiency treatment

Answer 11

High protein, high fat diet
Give sucrose prior to warm-up period and exercise
Prognosis is good with sedentary lifestyle

Question 12

Inherited disorder

Deposition of glycogen in cardiac and skeletal muscle

Answer 12

Pompe Disease

Type II

Question 13

Alpha 1,4 glucosidase (acid maltase) deficiency

Answer 13

Pompe disease

Type II

Question 14

Generalized glycogenesis because the defect is in all cells

Inability to convert mannose to glucose

Rapid progressive cardiomyopathy

Answer 14

Pompe’s disease

Question 15

Pompe’s disease hallmark

Answer 15

Rapid progressive cardiomyopathy

Question 16

Macroglossia
Hypotonia
Hepatomegaly

Death in 1-2 years of age

Answer 16

Pompe disease

Question 17

Pompe’s disease diagnosis

Answer 17

EKG: shortened PR interval!

Question 18

Pompe’s disease treatment

Answer 18

Recombinant alpha glucosidase to delay

enzyme replacement