Background <p>Glycogen storage disease type Ia is a rare inherited metabolic disorder often accompanied by renal complications; however, the dynamic progression and its renal pathology remain poorly understood.</p> Case presentation <p>We report a genetically confirmed Chinese Han female with glycogen storage disease type Ia followed up from childhood to early adulthood (over a 17-year period), documenting the complete natural history of renal involvement. Proteinuria emerged in her childhood (age 6 years), followed by the onset of estimated glomerular filtration rate decreasing and overt Fanconi syndrome in adolescence. Her renal involvement progressed to chronic kidney disease stage 3b in early adulthood, accompanied by a shift to predominantly glomerular-origin proteinuria (84.5%). Key renal biopsy findings revealed abundant glycogen granule deposition in renal tubular epithelial cells, accompanied by extensive tubulointerstitial pathology, while the glomeruli exhibited only secondary focal segmental sclerotic-like changes. The tubulointerstitial injury was more severe than the glomerular lesions.</p> Conclusion <p>This long-term clinicopathological correlation suggests a temporal sequence of renal injury in glycogen storage disease type Ia nephropathy, in which tubulointerstitial changes may precede overt glomerular involvement.</p>