The goal of this observational study is to determine if home lactate meters (both capillary and serum sample) are accurate, compared to lab serum lactate in a population of patients with glycogen storage disease type 1a and to determine if the Accu Chek Guide glucometer (capillary sample) is accurate, in a population of patients with glycogen storage disease type 1a.

The goal of this observational study is to determine if home lactate meters (both capillary and serum sample) are accurate, within 20% of lab serum lactate reading 95% of the time, in a population of patients with glycogen storage disease type 1a and to determine if the Accu Chek Guide glucometer (capillary sample) is accurate, within 20% of lab serum glucose reading 95% of the time, in a population of patients with glycogen storage disease type 1a.

Inclusion Criteria:

• Patients with diagnosed/confirmed (by liver biopsy or genetic testing) Glycogen Storage Disease Type Ia (ICD 10 code: E74.01).
• Connecticut Children's Emergency Department visit and/or admission to Connecticut Children's during time study is active
• For pediatric participants: Ability of child's parent/legal guardian to understand and the willingness to sign a written informed consent document
• For adults: Ability to understand and the willingness to sign a written informed consent

Exclusion Criteria:

• Patients with Glycogen storage disease unspecified 74.00, or Ib
• Patients not meeting inclusion criteria

Patients of Connecticut Children's birth to age 60 years with diagnosed Glycogen Storage Disease Type Ia, that are seen in clinic between 7/2020 - 7/2024, or that present to emergency room or are admitted to Connecticut Children's for surgery, acute illness or dose titration admission.