Annual Conference

  Wyboston Lakes


  Sat 10 and Sun 11 October

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Glycogen Storage Disease Type VI / GSD 6

Welcome to the AGSD-UK webpage for GSD VI.


GSD Type VI is also called Hers Disease.


Before reading too much about GSD VI, please be assured that with good dietary management, people can lead a normal life, can have unaffected children and should live into old age.



Initial symptoms can vary, common childhood symptoms are:

  • A swollen abdomen (tummy) due to an enlarged liver
  • A history of poor growth or short stature
  • Frequent feeding - always hungry
  • Episodes of low blood sugar (hypoglycaemia) on fasting
  • Excessive tiredness following activity


Potential complications in later life:

  • Cirrhosis (scarring) and /or adenomas on the liver
  • Pregnancy should be closely monitored


Those affected by GSD VI may find their symptoms lessen as they become adults. We generally need less energy as we get older because we are not growing.



Diagnosis of GSD VI is made on the basis of symptoms and/or following the results of a physical examination and blood test results.



GSD VI is caused by a defect in the phosphorylase enzyme.

The defective enzyme prevents glucose from being properly extracted and so glycogen continues to build up in the body. This accounts for the enlarged liver and swollen abdomen and produces symptoms of low blood sugar.  Periods of low blood sugar in GSD VI are milder than other types of GSD as those with type VI can also make glucose from protein.



The AGSD-UK Coordinator for GSD VI is Caroline Calder, who has the condition herself. (This is a voluntary role.) Everyone in the UK diagnosed with GSD VI should register with Caroline to be kept up-to-date with developments. You can contact her via the Contact us page.