Inborn Errors of Carbohydrates

Question 1

Galactosemia deficiency in

Answer 1

galactose-1-phosphate uridyl transferase (GALT) - most common, galactokinase (GALK), or uridine diphosphate galactose-4-epimerase (GALE)

Question 2

Galactosemia presentation

Answer 2

Mental retardation, failure to thrive, galactosuria (+Clinitest)

Question 3

Hepatic glycogenoses presentation

Answer 3

Hepatomegaly, hypoglycemia, growth retardation

Question 4

Von Gierke disease features

Answer 4

Most common hepatic glycogenosis; hypoglycemia, lactic acidosis, hyperuricemia

Question 5

Muscle glycogenoses presentation

Answer 5

Exercise intolerance, muscle cramps, fatigue, weakness

Question 6

GSD Type 0 deficient enzyme

Answer 6

Glycogen synthase

Question 7

GSD Type Ia (von Gierke) deficient enzyme

Answer 7

Glucose-6-phosphatase

Question 8

GSD Type Ib deficient enzyme

Answer 8

Glucose-6-phosphatase translocase

Question 9

GSD Type II (Pompe) deficient enzyme

Answer 9

Lysosomal acid alpha-glucosidase

Question 10

GSD Type IIIa (Cori-Forbes) deficient enzyme

Answer 10

Glycogen debranching enzyme

Question 11

GSD Type IIIb deficient enzyme

Answer 11

Glycogen debranching enzyme

Question 12

GSD Type IV (Andersen) deficient enzyme

Answer 12

Glycogen branching enzyme

Question 13

GSD Type V (McArdle) deficient enzyme

Answer 13

Phosphorylase (muscle phosphorylase)

Question 14

GSD Type VI (Hers) deficient enzyme

Answer 14

Glycogen phosphorylase

Question 15

GSD Type VII (Tarui) deficient enzyme

Answer 15

Phosphofructokinase

Question 16

GSD Type IXa deficient enzyme

Answer 16

Phosphorylase kinase

Question 17

GSD Type IXb deficient enzyme

Answer 17

Phosphorylase

Question 18

GSD Type XI (Fanconi-Bickel) deficient enzyme

Answer 18

Glucose transporter 2

Question 19

Galactosemia lab feature

Answer 19

Elevated blood and urine galactose

Question 20

Galactosemia clinical features

Answer 20

Jaundice, hepatomegaly, galactosuria, E. coli sepsis, cataract, hypotonia, sensory neural deafness

Question 21

Galactosemia diagnostic test

Answer 21

Erythrocyte galactose-1-phosphate uridyl transferase activity

Question 22

Essential fructosuria cause

Answer 22

Autosomal recessive disorder due to fructokinase deficiency

Question 23

Essential fructosuria feature

Answer 23

Unconverted fructose in plasma

Question 24

Essential fructosuria diagnostic indicator

Answer 24

Presence of fructose in urine

Question 25

Hereditary fructose deficiency cause

Answer 25

Defect of fructose-1,6-bisphosphate aldolase B activity in liver, kidney, intestine

Question 26

Hereditary fructose deficiency clinical features

Answer 26

Irritability, lethargy, seizures, hepatomegaly

Question 27

Fructose-1,6-bisphosphate deficiency cause

Answer 27

Defect in fructose-1,6-bisphosphate enzyme affecting hepatic glucose generation

Question 28

Fructose-1,6-bisphosphate deficiency features

Answer 28

Hypoglycemia, lactic acidosis, convulsions, coma

Question 29

Glycogen storage disease cause

Answer 29

Inherited autosomal recessive deficiency of specific enzymes for glycogen metabolism

Question 30

GSD liver-related types

Answer 30

Types I, III, IV, VI, IX, 0 (cause liver damage)

Question 31

GSD muscle-related types

Answer 31

Types V, VII (cause muscular defects)

Question 32

Von-Gierke disease

Answer 32

GSD Type I; most common glycogen storage disease

Question 33

GSD diagnostic test

Answer 33

Intravenous galactose tolerance test (low glucose levels in Type I)