IgA nephropathy in a girl with mitochondrial disease

Area of Science:

• Nephrology
• Pediatrics
• Genetics

Background:

• Mitochondrial renal disease is a significant, potentially underestimated, cause of end-stage renal disease in children.
• IgA nephropathy (IgAN) is a common primary glomerulonephritis.

Observation:

• A 13-year-old girl presented with proteinuria, short stature, and hearing loss, later diagnosed with mitochondrial disease (MD) and IgA nephropathy (IgAN).
• Her younger sister exhibited similar symptoms, suggesting a potential genetic link.
• Renal biopsy revealed focal segmental mesangial proliferation with IgA deposition and abnormal mitochondria in proximal tubular cells.

Findings:

• Electron microscopy confirmed significant mitochondrial proliferation in renal tubular cells.
• Enzyme assays on cultured skin fibroblasts showed decreased activity in mitochondrial respiratory chain complexes I and IV.
• This case highlights the potential co-occurrence of IgAN and MD.

Implications:

• Underlying mitochondrial disease should be considered in pediatric patients with urinary abnormalities, particularly those with multi-organ involvement.
• This case broadens the understanding of the clinical spectrum of mitochondrial diseases.
• Further research is needed to elucidate the relationship between IgAN and MD.