Diagnosis of GSD in neonates involves a combination of clinical evaluation, biochemical tests, and genetic analysis: - Biochemical Tests: Blood tests to measure glucose levels, liver enzymes, lactate, and uric acid. - Enzyme Assays: Direct measurement of the activity of the deficient enzyme in tissues or blood. - Genetic Testing: Identification of mutations in specific genes responsible for GSD. - Imaging Studies: Ultrasound or MRI to assess liver and muscle involvement.