Genetic Traits and Health Effects of IgA Nephropathy

Last reviewed: May 12, 2026 Last updated: May 12, 2026

Written by: Jay Hastings , CEO of PlexusDx

Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations. He has more than 20 years of experience across healthcare innovation, genomics, laboratory operations, healthcare investing, and strategic finance. His work has included scaling healthcare startups, leading CLIA lab integrations, and helping expand consumer access to precision health tools.

Medically reviewed by: Jayden Lee, PharmD, EMBA

Jayden Lee, PharmD, EMBA, is the PlexusDx Medical Science Liaison with a PharmD and MBA specializing in pharmacogenomics and clinical product development, with a proven ability to bridge the gap between genomic research and practical patient outcomes. Dr. Lee has more than 10 years of professional experience in clinical pharmacy, academia, and research.

This article is part of the PlexusDx Education Hub — your resource for evidence-based guidance on genetics & kidney health. Browse all Genetics & Kidney Health education

IgA nephropathy, also called Berger's disease, is the most common primary glomerular kidney disease worldwide. It develops when a specific antibody, immunoglobulin A, builds up in the kidney's filtering units and provokes inflammation. Its course ranges from harmless microscopic findings to progressive kidney damage, and genetics plays a clear role in both who develops it and how it behaves.

What is IgA nephropathy?

The kidneys filter blood through roughly a million tiny units called glomeruli. In IgA nephropathy, abnormal IgA antibodies deposit in the mesangium, the supportive tissue of these units, triggering inflammation that can scar the filter over time. Many people first learn of it after a routine urine test shows blood or protein, or after visibly bloody urine follows a cold or throat infection — a hallmark timing that reflects the disease's link to mucosal immunity.

The four-hit pathogenesis model

Researchers describe IgA nephropathy through a four-hit sequence. First, the body produces IgA1 that is missing a normal galactose sugar (galactose-deficient IgA1). Second, the immune system makes autoantibodies against this abnormal IgA1. Third, the two combine into immune complexes circulating in the blood. Fourth, those complexes deposit in the kidney mesangium and drive inflammation. Genetics influences several of these steps, particularly the tendency to produce galactose-deficient IgA1 and the mucosal immune response behind it.

The genetics: risk loci and what they reveal

Genome-wide association studies have identified more than a dozen risk regions. The strongest signals sit in the HLA region on chromosome 6 — particularly HLA-DQ and HLA-DR genes that govern immune recognition. A deletion of the complement genes CFHR3 and CFHR1 is protective, pointing to the complement system's role. Variants near TNFSF13 (which encodes APRIL, a driver of IgA production) and the alpha-defensin DEFA genes also contribute. Notably, these risk variants are far more common in East Asian and European populations than in African populations, mirroring the disease's striking geographic distribution.

Health effects and progression

Outcomes vary widely. Some people have only intermittent microscopic blood in the urine and stable kidney function for life. Others develop rising protein in the urine, high blood pressure, and gradual loss of filtering capacity that can progress toward kidney failure over years to decades. Higher protein levels, elevated blood pressure, and reduced kidney function at diagnosis are among the factors associated with faster progression, which is why monitoring matters.

Working with a nephrologist

Management is individualized and belongs with a kidney specialist. Broadly, evidence-based care centers on controlling blood pressure, reducing protein in the urine, and monitoring kidney function over time; a nephrologist determines the specifics based on biopsy findings and risk. This article is educational and describes the general clinical context — it does not prescribe treatment. Anyone with blood or protein in their urine should be evaluated by a qualified provider.

Where genetic insight fits your bigger picture

Genetics explains part of why IgA nephropathy runs in some families and populations, but it is only one piece. The PlexusDx Precision Peptide Genetic Test analyzes 14 pathways, 49 peptides, 150+ genetic insights across peptide-related biological pathways. It is educational and does not diagnose, treat, or manage IgA nephropathy or any kidney condition; diagnosis requires clinical evaluation and, typically, a kidney biopsy ordered by a nephrologist.

Frequently Asked Questions About IgA Nephropathy Genetics

Is IgA nephropathy hereditary?

IgA nephropathy has a strong genetic component but is rarely caused by a single gene. Risk variants cluster in the HLA region and in complement genes like CFHR3 and CFHR1, and the disease can run in families. Most cases arise from many risk variants combined with environmental and immune triggers.

What are the main health effects of IgA nephropathy?

Effects range from harmless microscopic blood in the urine to progressive kidney damage. Common findings include blood and protein in the urine, high blood pressure, and, in some people, gradual loss of kidney function over years. Higher protein and blood pressure at diagnosis are linked to faster progression.

Does a genetic test diagnose IgA nephropathy?

No. IgA nephropathy is diagnosed by a nephrologist, usually with a kidney biopsy showing IgA deposits, alongside urine and blood tests. Genetic testing can add context about inherited risk in the HLA and complement pathways, but it cannot diagnose the disease or replace clinical evaluation.

Explore the biology behind your health picture. Explore the Precision Peptide Genetic Test to understand more about your peptide-related biology — genetics as a guide, not a guarantee.

This article is part of the PlexusDx Education Hub. Browse all Genetics & Kidney Health education

The Precision Peptide Genetic Test analyzes how your genes influence peptide-related biological pathways. It does not recommend, prescribe, or determine which peptides you should use. Consult a qualified healthcare provider before beginning any peptide protocol.

Medical and Editorial Standards

Medical review process: This article was reviewed for medical accuracy, scientific clarity, evidence alignment, and appropriate discussion of genetics, medications, supplements, biomarkers, and health-related claims.

Sources and evidence: PlexusDx educational content is developed using peer-reviewed research, clinical literature, reputable medical references, and, where applicable, public health or regulatory guidance. References are included at the end of the article when scientific, medical, or health-related claims are discussed.

Commercial transparency: PlexusDx offers genetic testing, blood biomarker testing, personalized supplement recommendations, and related precision wellness services. Product mentions are intended to help readers understand available options and should not be interpreted as medical advice.

Important disclaimer: PlexusDx educational content is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about medications, supplements, genetic testing, lab testing, or health-related care.