HLA-B*57:01

What is HLA-B*57:01?

HLA-B*57:01 is a variant of a human leukocyte antigen (HLA) gene, the system the immune system uses to present fragments of proteins — including drugs bound to proteins — to T cells. Particular HLA alleles bind particular drugs, which is why carrying one can turn an ordinarily safe medicine into a severe immune reaction, and why some alleles track autoimmune conditions.

Tag SNP rs2395029 in HCP5 gene is in near-perfect LD with HLA-B*57:01 in European populations (r²=0.999). PPV >99.9% in Europeans.

How common is HLA-B*57:01?

Drug reactions linked to HLA-B*57:01

Abacavir Hypersensitivity Syndrome high risk

HLA-B*57:01 carriers should NOT be prescribed abacavir. Use an alternative antiretroviral agent. FDA and CPIC recommend HLA-B*57:01 testing before initiating abacavir therapy.
Evidence: CPIC Level A (Strong); FDA Black Box Warning · Source: CPIC Guideline for Abacavir and HLA-B (2014, updated 2024) · HLA-B*57:01 prevalence: ~5-8% in Europeans, ~1% in East Asians, ~1-2% in Africans.

How is HLA-B*57:01 inferred from a consumer DNA file?

Consumer chips do not sequence HLA genes. HLA-B*57:01 is inferred from the tag SNP rs2395029 (risk allele G), which travels with the HLA allele on the same stretch of chromosome. How reliably it does so (r²) differs by ancestry:

A tag-SNP call is a probability, not a laboratory HLA type. A positive result that would change a prescription should be confirmed by clinical HLA typing.