Quick Carb Disorder Cards

Galactosemia, Classic

• Most Identifiable Symptom: E. coli sepsis in the neonatal period, liver failure. POI in females. Liver failure.

• Key Biochemical Finding: Elevated galactose-1-phosphate (Gal-1-P); absent GALT enzyme activity.

• Treatment: Immediate lactose-restricted diet (lactose-free formula).

Galactosemia, Duarte

• Most Identifiable Symptom: Asymptomatic.

• Key Biochemical Finding: ~50% GALT activity (homozygous Duarte) or ~25% (compound heterozygous with classic allele); Gal-1-P may rise with lactose challenge.

• Treatment: Often asymptomatic; temporary restriction may be used.

Galactosemia, Variant

• Most Identifiable Symptom: Variable, 1-10% GALT activity.

• Key Biochemical Finding: Low GALT activity (1-10%); elevated Gal-1-P, especially post-lactose challenge.

• Treatment: No uniform consensus; "lactose challenge" used to guide management.

Galactokinase Deficiency

• Most Identifiable Symptom: Cataracts.

• Key Biochemical Finding: Elevated galactose/Gal-1-P (mechanism different from GALT).

• Treatment: Lactose restriction to prevent/resolve cataracts.

Epimerase Deficiency Galactosemia (GALE)

• Most Identifiable Symptom: Ranges from benign to severe liver disease.

• Key Biochemical Finding: Deficiency of UDP-galactose 4-epimerase.

• Treatment: Depends on severity; POI not reported.

Hereditary Fructose Intolerance (ALDOB deficiency)

• Most Identifiable Symptom: Acute symptoms (nausea, lethargy, liver failure) upon fructose ingestion; fructose aversion.

• Key Biochemical Finding: Hypoglycemia, hypophosphatemia after fructose intake.

• Treatment: Eliminate dietary fructose, sucrose, and sorbitol.

Glucose-6-Phosphate Dehydrogenase Deficiency (G6PD)

• Most Identifiable Symptom: Episodes of acute hemolytic anemia triggered by oxidative stressors (drugs, fava beans).

• Key Biochemical Finding: Deficiency of enzyme (X-linked).

• Treatment: Avoid triggers (certain medications, fava beans).

Glycogen Storage Disease Type 0a (GYS2 deficiency)

• Most Identifiable Symptom: Ketotic hypoglycemia; NO hepatomegaly.

• Key Biochemical Finding: Post-prandial hyperglycemia; lactic acidemia.

• Treatment: Prevent fasting hypoglycemia and hyperketosis; prognosis excellent with treatment.

Glycogen Storage Disease Type Ia (Von Gierke disease)

• Most Identifiable Symptom: Severe fasting hypoglycemia, hepatomegaly, "doll-like facies".

• Key Biochemical Finding: Lactic academia, hyperlipidemia, hypoglycemia without ketosis.

• Treatment: Prevent fasting hypoglycemia; high mortality without treatment; long-term complications (renal disease) common.

Glycogen Storage Disease Type Ib

• Most Identifiable Symptom: Severe fasting hypoglycemia, hepatomegaly, "doll-like facies", plus frequent bacterial infections due to neutrophil dysfunction.

• Key Biochemical Finding: Lactic acidemia, hyperlipidemia, hypoglycemia without ketosis.

• Treatment: Prevent fasting hypoglycemia; high mortality without treatment; long-term complications (renal disease) common.

Glycogen Storage Disease Type II (Pompe disease)

• Most Identifiable Symptom: Infantile: cardiomyopathy, hypotonia. Late-onset: progressive myopathy.

• Key Biochemical Finding: Deficiency of acid alpha-glucosidase (acid maltase); glycogen storage in lysosomes.

• Treatment: Enzyme replacement therapy (alglucosidase alfa/Lumizyme); immunomodulation if CRIM-negative.

Glycogen Storage Disease Type V (McArdle disease)

• Most Identifiable Symptom: Exercise intolerance, myalgia, "second wind" phenomenon.

• Key Biochemical Finding: Deficiency of myophosphorylase (PYGM); elevated CK at rest; elevated ammonia/lactate after exercise.

• Treatment: Management of exercise; ingestion of oral sucrose before activity may help.

GLUT2 Deficiency

• Most Identifiable Symptom: Transient neonatal diabetes, hepatomegaly, renal tubular disease.

• Key Biochemical Finding: Deficiency of glucose transporter SLC2A2.

• Treatment: Restrict glucose and galactose.

Congenital Disorders of Glycosylation (CDG) - PMM2-CDG (most common)

• Most Identifiable Symptom: Multisystem abnormalities from birth (CNS, dysmorphic features, hypotonia, coagulation defects).

• Key Biochemical Finding: Abnormal carbohydrate-deficient transferrins (CDT).

• Treatment: Supportive.