Glycosade v UCCS in the Dietary Management of Hepatic GSD

Inclusion Criteria: * Diagnosed by either genetic mutation analysis or enzymology study (this includes patients with only a single mutation but who also have supportive enzymology consistent with the condition). For those whom mutation analysis is not completed this will be assessed during the study. * Aged 2 years or older (5 years or older in the USA) * Established on full intake of uncooked corn starch therapy for at least 6 months Exclusion Criteria: * Women who are pregnant or breastfeeding at the start of the study or planning to become pregnant during the study will be excluded. * children less than 2 years of age