Glycogen storage disease type III




Glycogen storage disease type III


Population genetics

Mendelian genetics and punnett squares

Hardy-Weinberg equilibrium

Inheritance patterns

Independent assortment of genes and linkage

Evolution and natural selection

Genetic disorders

Down syndrome (Trisomy 21)

Edwards syndrome (Trisomy 18)

Patau syndrome (Trisomy 13)

Fragile X syndrome

Huntington disease

Myotonic dystrophy

Friedreich ataxia

Turner syndrome

Klinefelter syndrome

Prader-Willi syndrome

Angelman syndrome

Beckwith-Wiedemann syndrome

Cri du chat syndrome

Williams syndrome

Alagille syndrome (NORD)


Polycystic kidney disease

Familial adenomatous polyposis

Familial hypercholesterolemia

Hereditary spherocytosis

Huntington disease

Li-Fraumeni syndrome

Marfan syndrome

Multiple endocrine neoplasia

Myotonic dystrophy


Treacher Collins syndrome

Tuberous sclerosis

von Hippel-Lindau disease


Polycystic kidney disease

Cystic fibrosis

Friedreich ataxia

Gaucher disease (NORD)

Glycogen storage disease type I

Glycogen storage disease type II (NORD)

Glycogen storage disease type III

Glycogen storage disease type IV

Glycogen storage disease type V


Mucopolysaccharide storage disease type 1 (Hurler syndrome) (NORD)

Krabbe disease


Niemann-Pick disease types A and B (NORD)

Niemann-Pick disease type C

Primary ciliary dyskinesia

Phenylketonuria (NORD)

Sickle cell disease (NORD)

Tay-Sachs disease (NORD)



Wilson disease

Fragile X syndrome

Alport syndrome

X-linked agammaglobulinemia

Fabry disease (NORD)

Glucose-6-phosphate dehydrogenase (G6PD) deficiency


Mucopolysaccharide storage disease type 2 (Hunter syndrome) (NORD)

Lesch-Nyhan syndrome

Muscular dystrophy

Ornithine transcarbamylase deficiency

Wiskott-Aldrich syndrome

Mitochondrial myopathy

Autosomal trisomies: Pathology review

Muscular dystrophies and mitochondrial myopathies: Pathology review

Miscellaneous genetic disorders: Pathology review


Glycogen storage disease type III


0 / 12 complete

USMLE® Step 1 questions

0 / 3 complete

High Yield Notes

7 pages


Glycogen storage disease type III

of complete


USMLE® Step 1 style questions USMLE

of complete

A 1-year-old girl is brought to the clinic for evaluation of poor growth and poor muscle tone. The mother states that the patient “doesn’t seem to be gaining weight,” despite adequate feedings. Temperature is 36.4°C (97.5°F), pulse is 98/min, blood pressure is 104/64, and respiratory rate is 35/min. Motor examination reveals diffuse hypotonia in all 4 limbs. Abdominal examination reveals hepatomegaly. Rapid fingerstick glucose is 40 mg/dL. Echocardiogram reveals left ventricular hypertrophy. Serum lactate levels are within normal limits. A liver biopsy reveals widespread fibrosis with minimal fat infiltration. Further analysis reveals accumulation of limit dextrin-like complexes in the cytosol of hepatocytes. Which of the following is the most likely diagnosis? 

External References

First Aid








Cori disease p. 85

Debranching enzyme

Cori disease p. 85

External Links


Glycogen storage disease type III is one of the genetic disorders affecting how the body stores and uses glycogen. People with glycogen storage disease type III have a deficiency of the glycogen debrancher enzyme (α-1,6-glucosidase), one of the enzymes that help to break down glycogen. The symptoms of glycogen storage disease type III generally appear during childhood and include generalized muscle weakness, hepatosplenomegaly, fasting hypoglycemia, and ketosis.


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