In GSD6 the defective enzyme prevents glucose from being properly extracted from liver glycogen. Therefore glycogen continues to build up in the liver. This accounts for the enlarged liver and swollen abdomen and produces symptoms of low blood sugar.

Periods of low blood sugar in GSD6 are milder than in other GSDs as people with GSD6 can also make glucose from protein.

Initial symptoms can vary, common childhood symptoms are: a swollen abdomen 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, and excessive tiredness following activity.

However, with good dietary management, people wih GSD6 can lead a normal life, can have unaffected children and should live into old age.

Potential complications in later life can include cirrhosis (scarring) and/or adenomas on the liver. Pregnancy should be closely monitored. Those affected by GSD6 may find their symptoms lessen as they become adults. We generally need less energy as we get older because we are not growing.