Liver histology in children with glycogen storage disorders type VI and IX

Area of Science:

• Pediatric Hepatology
• Genetic Metabolic Disorders
• Gastroenterology

Background:

• Glycogen storage diseases (GSD) types VI and IX result from liver phosphorylase system deficiencies.
• These GSD types are clinically indistinguishable, presenting challenges in diagnosis.

Purpose of the Study:

• To evaluate the diagnostic value of liver biopsy in children with GSD VI and IX.
• To correlate clinical features, molecular analysis, and imaging with histopathological findings.

Main Methods:

• Retrospective review of 22 pediatric patients diagnosed with GSD VI or IX between 2001 and 2018.
• Reassessment of liver histology by a single pathologist, alongside review of clinical data, molecular analysis, and imaging.

Main Results:

• Hepatomegaly and elevated AST were common presenting features.
• Liver biopsies revealed varying degrees of fibrosis (METAVIR F1-F4, ISHAK F2-F5), hepatocyte glycogenation, steatosis, and inflammation.
• Histopathological findings differed across GSD subtypes, with GSD IXa showing fibrosis scores F1-F3 (METAVIR).

Conclusions:

• Chronic histological changes are evident in liver biopsies of GSD VI and IX, even when clinically mild.
• Histopathology offers superior insight into liver involvement compared to biochemical markers.
• Definitive classification of GSD VI and IX requires molecular analysis, complementing histopathological assessment.