Whether an infection becomes chronic is decided largely by the host, and the strongest host signal is in the genes that decide what the immune system is shown.
Solid lines are connections this site curates. Dashed lines mean the two ends share a research paper — worth knowing, and not a claim that one explains the other.
Hepatitis B is a virus. Whether it is a passing illness or a lifelong infection is not decided by the virus alone — it is decided substantially by the person it infects, and most powerfully by their age at infection. Infected as an adult, most people clear it. Infected as an infant, most do not.
Underneath that, genetics accounts for a real part of the remainder, and the loci say something specific about which part of immunity is doing the work.
rs3077 lies at HLA-DPA1. HLA class II molecules present fragments of protein to helper T cells — they are how the immune system is shown what it is fighting. When the strongest genetic signal for whether an infection persists is in the genes that do the showing, that is a statement about mechanism, not a coincidence.
A Japanese study extended this. After the HLA-DP association was established, a scan of 519,747 positions in 458 cases against 2,056 controls found two positions in the HLA-DQ locus, replicated in 2,209 cases and 4,440 controls, reaching overall p-values of 5.98 × 10⁻²⁸ and 3.99 × 10⁻³⁷ — and independent of the HLA-DP signals already known.
So this is not one HLA association with company. It is several, in adjacent genes, acting separately.
rs11866328 is in GRIN2A, a glutamate receptor subunit gene — which is not where anyone would look for hepatitis biology.
It was found by a study that asked a different question: not who becomes a chronic carrier, but which chronic carriers get worse. It compared 628 asymptomatic carriers against 1,729 who had progressed in Hubei (odds ratio 1.65, 95% CI 1.34–2.02) and replicated it in 226 against 215 in Shandong (odds ratio 1.73, 95% CI 1.14–2.65).
Two different questions, two different sets of genes. Whether you clear a virus and whether you deteriorate while carrying it are not the same trait, and the site keeps them apart on this page for that reason.
Both studies are East Asian — Japanese and Chinese. That is not a limitation to be apologised for; it is where the disease burden is, and hepatitis B genetics is one of the few areas where the major studies were done in the populations most affected.
It does mean the effect sizes should not be assumed to transfer, and HLA allele frequencies differ between populations more than almost anything else in the genome.
There is a vaccine, it works, and it is given at birth in most of the world. It is the single most effective thing that has ever been done about hepatitis B, and no genotype competes with it.
For people already infected, chronic hepatitis B is monitored and treated with antivirals that suppress the virus. Whether and when to treat is decided on viral load, liver enzymes and the state of the liver — not on genotype.
See also chronic hepatitis C, where host genetics did briefly change treatment, and then the drugs changed instead.
Sources. Hu et al. (Hum Mol Genet 2011) followed earlier identification of HLA-DP variants in chronic hepatitis B with a genome-wide scan of 519,747 SNPs in 458 Japanese cases and 2,056 controls, then tested the leading signals in an independent 2,209 cases and 4,440 controls. Two SNPs in the HLA-DQ locus, rs2856718 and rs7453920, reached overall p-values of 5.98 × 10⁻²⁸ and 3.99 × 10⁻³⁷ and remained significant after stratification on rs3077 and rs9277535, indicating an effect independent of the HLA-DP variants. Zhang et al. (Viral Immunol 2011) used genome-wide association with DNA pooling to study disease progression rather than susceptibility, and reported rs11866328 in GRIN2A associated with progression in 628 asymptomatic against 1,729 progressed carriers in Hubei (OR 1.65, 95% CI 1.34–2.02, p = 1.96 × 10⁻⁶, additive model), replicated in 226 against 215 in Shandong (OR 1.73, 95% CI 1.14–2.65).
Positions listed here. rs3077 (HLA-DPA1) and rs11866328 (GRIN2A). The HLA-DQ index SNPs rs2856718 and rs7453920 are not in our variant table.
Two phenotypes, kept separate. Susceptibility to chronic infection and progression within chronic infection are distinct endpoints with distinct study designs, and combining them would misattribute an effect on one to the other.
Clinical use. None. Diagnosis and staging rest on serology, HBV DNA quantification, liver enzymes and assessment of fibrosis. Treatment decisions with nucleos(t)ide analogues follow those measures. Vaccination is the primary preventive intervention and is not genotype-directed.
What a 23andMe/AncestryDNA export or raw VCF can and can't tell you about Chronic Hepatitis B comes down to these specific, well-studied positions — not a diagnosis.
It contributes, and age at infection contributes far more. Infected as an adult most people clear it; infected in infancy most do not. HLA class II variation is the strongest genetic signal, and it shifts odds rather than deciding outcomes.
Nobody expected it, and the honest position is that the mechanism is not established. It was found by asking a different question — which chronic carriers deteriorate, rather than who becomes one — in two Chinese cohorts, and it replicated. A replicated association without a mechanism is a lead, not an explanation.
Yes, and it is not genetic. There is an effective vaccine given at birth in most of the world, and for people already infected there are antivirals that suppress the virus. Treatment decisions follow viral load, liver enzymes and the state of the liver.
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