[Identical twin sisters with IgA nephropathy]

Area of Science:

• Nephrology
• Immunogenetics

Background:

• Immunoglobulin A (IgA) nephropathy is a common cause of glomerulonephritis.
• Familial clustering and human leukocyte antigen (HLA) associations suggest a genetic predisposition.

Observation:

• Presents identical twin sisters diagnosed with IgA nephropathy at different ages.
• Both cases exhibited microscopic hematuria and proteinuria, with normal physical exams and serum IgA levels.
• Renal biopsies revealed mesangial proliferation and IgA deposition.

Findings:

• Identical twins shared specific HLA serotypes, including HLA-Bw35.
• The findings support a potential role for HLA-linked immune responses in IgA nephropathy development.

Implications:

• Suggests a genetic component influencing IgA nephropathy susceptibility in familial cases.
• Highlights the importance of HLA typing in understanding the pathogenesis of IgA nephropathy.