Adult patients exhibit normal stature, motor function, and biochemical parameters. Rare variants of GSD may cause muscle dysfunction or severe cardiomyopathy. GSD VI is most common among members of the Mennonite religious group. All other forms of GSD VI are autosomal-recessive and affect both sexes equally. These children also may have histories of mild fasting hypoglycemia and hypotonia.
Some patients remain asymptomatic, and routine physical examination reveals hepatomegaly.
Although children may have growth delay and short stature, adolescents and adults often have normal stature. The abdomen of a child with GSD VI usually protrudes, and abdominal examination reveals hepatomegaly and increased liver span. In some cases, hepatomegaly may be massive. Splenomegaly, however, always is absent. Adult patients may have mild or no hepatomegaly.