Glycogen Storage Diseases

Question 1

For the following disease, provide the type, defective enzyme, affected organ, how glycogen changes, and clinical features:

Von Gierke Disease

Answer 1

Type: I

Defective enzyme: glucose 6 phosphatase (deficient enzyme or translocase)

Affected Organ: liver and kidney

Glycogen: increased, normal structure

Clinical Features: enlarged liver, failure to thrive, sever hypoglycemia, hyperuricemia, gouty arthritis, hyperlipidemia, mental retardation, lactic acidosis

Question 2

For the following disease, provide the type, defective enzyme, affected organ, how glycogen changes, and clinical features:

Pompe Disease

Answer 2

Type: II

Defective enzyme: 1,4 alpha glucosidase (lysosomal acid maltase)

Affected Organ: all organs

Glycogen: massive increase, normal structure

Clinical Features: cardiorespiratory failure, death usually before age 2

Question 3

For the following disease, provide the type, defective enzyme, affected organ, how glycogen changes, and clinical features:

Cori Disease

Answer 3

Type: III

Defective enzyme: glycogen debranching enzyme

Affected Organ: muscle and liver

Glycogen: increased short outer

Clinical Features: like type I but milder (enlarged liver, failure to thrive, sever hypoglycemia, hyperuricemia, gouty arthritis, hyperlipidemia, mental retardation, lactic acidosis)

Question 4

For the following disease, provide the type, defective enzyme, affected organ, how glycogen changes, and clinical features:

Anderson Disease

Answer 4

Type: IV

Defective enzyme: glycogen branching enzyme

Affected Organ: liver and spleen

Glycogen: normal amount; long branches

Clinical Features: progressive cirrhosis of liver. Liver failure causes death before age 2

Question 5

For the following disease, provide the type, defective enzyme, affected organ, how glycogen changes, and clinical features:

McArdle Disease

Answer 5

Type: V

Defective enzyme: phosphorylase

Affected Organ: muscle

Glycogen: moderate amount; normal structure

Clinical Features: limited ability to perform strenuous exercise; painful muscle cramps

Question 6

For the following disease, provide the type, defective enzyme, affected organ, how glycogen changes, and clinical features:

Hers Disease

Answer 6

Type: VI

Defective enzyme: phosphorylase

Affected Organ: liver

Glycogen: increased amount

Clinical Features: like 1, but milder, (enlarged liver, failure to thrive, sever hypoglycemia, hyperuricemia, gouty arthritis, hyperlipidemia, mental retardation, lactic acidosis)

Question 7

For the following disease, provide the type, defective enzyme, affected organ, how glycogen changes, and clinical features:

Tauri Disease

Answer 7

Type: VII

Defective enzyme: PFK-1

Affected Organ: muscle

Glycogen: increased amount

Clinical Features: like V ( limited ability to perform strenuous exercise; painful muscle cramps)

Question 8

For the following disease, provide the type, defective enzyme, affected organ, how glycogen changes, and clinical features:

VIII

Answer 8

Type: VIII

Defective enzyme: phosphorylase b kinase

Affected Organ: liver

Glycogen: increased amount; normal structure

Clinical Features: mild liver enlargement; mild hypoglycemia

Question 9

For the following defective enzyme, provide the affected organ, how glycogen changes, and clinical features:

glycogen synthase

Answer 9

Affected Organ: liver

Glycogen: decreased

Clinical features: hypoglycemia, postprandial lactic acidemia, fasting ketosis