Biochem June 25

Question 1

Inheritance of glycogen storage diseases I-IV?

Answer 1

autosomal recessive

Question 2

what is glycogen storage disease I?

Answer 2

Von Gierke disease

Question 3

what is glycogen storage disease II?

Answer 3

Pompe Disease

Question 4

what is glycogen storage disease III?

Answer 4

Cori disease

Question 5

what is glycogen storage disease IV?

Answer 5

McArdle

Question 6

Which enzyme is deficient in Von Gierke Disease?

Answer 6

Glucose 6 Phosphatase

Question 7

Lab findings in Von Gierke Disease

Answer 7

Severe fasting hypoglycemia (cant complete glycogenolysis or gluconeogenesis

-Increased glycogen in liver/kidneys, high blood lactate, high triglycerides, high uric acid, hepatomegaly and renomegaly

Question 8

Why does lactic acidosis occur with Von Gierkes diseasE?

Answer 8

the cori cycle requires G6P which cannot be produced, leading to lactate build up

Question 9

what pathways are impaired in von gierkes?

Answer 9

Gluconeogensis, glycogenolysis, consequently cori cycle

Question 10

how to treat Von gierkes

Answer 10

frequent oral glucose/cornstarch

AVOID fructose/galactose which feed into glycolysis

Question 11

what is deficient in Pompe disease?

Answer 11

Lysosomal acid alpha-1-4-glucosidase

Question 12

can gluconeogenesis be performed in pompe disease?

Answer 12

yes - its just muscle glycogenolysis that is impaired

Question 13

clinical manifestions of pompe disease

Answer 13

Cardiomegaly, hypertrophic cardiomyopathy, hypotonia, excercise intolerance, early death

Question 14

what accumulates in pompe disease (type II) ?

Answer 14

glycogen accumulates in lysosomes

Question 15

What enzyme is deficient in cori disease?

Answer 15

debranching enzyme (alpha 1,6 glucosidase)

Question 16

Findings in cori disease

Answer 16

mild hypoglycemia (milder form of von gierkes)

• normal blood lactate
• accumulation of limit dextrin-like structures in cytoplasm

Question 17

does cori disease (type III) have intact gluconeogenesis?

Answer 17

yes

Question 18

Which organs are primarily effected in cori disease?

Answer 18

Muscles

-may lead to cardiomyopathy

Question 19

What is deficient in McArdle disease?

Answer 19

Skeletal muscle glycogen phosphorylase

Question 20

Lab finding hallmark of mcardle disease?

Answer 20

FLAT venous lactate curve with normal rise in ammonia levels during exercise

Question 21

Presentation of McArdle disease

Answer 21

Painful muscle cramps, myoglobinuria with strenous exercise, and arythmia from electrolyte abnormalities
Second wind phenomonen due to increased muscular blood flow

Question 22

Which organs are primarily effect in mcardle disaese?

Answer 22

muscles - glycogen builds up but muscles cannot break it down

Question 23

Does mcardle disease have intact gluconeogenesis?

Answer 23

yes

Question 24

What is type 0 glycogen storage disease?

Answer 24

Glycogen synthase deficiency, resulting in no glycogen and thus hypoglycemia but no hepatomegaly