HLA-A29

HLA-A29 is a human leukocyte antigen serotype within HLA-A serotype group. The serotype is determined by the antibody recognition of α29 subset of HLA-A alleles. HLA-A29 is more frequently found in individuals with birdshot chorioretinopathy. This disease is a rare form of posterior uveitis, which can lead to vision loss.

Structure and Function

HLA-A29 is a MHC class I molecule, which is a type of protein found on the surface of all nucleated cells. It plays a crucial role in the immune system's recognition of foreign substances. HLA-A29, like other MHC class I molecules, presents peptides (small proteins) from inside the cell to T cells, a type of white blood cell. If these peptides are derived from foreign pathogens, such as viruses or bacteria, the T cells can then kill the infected cells.

Association with Birdshot Chorioretinopathy

HLA-A29 is strongly associated with birdshot chorioretinopathy, a rare form of inflammatory eye disease. More than 95% of patients with this condition carry the HLA-A29 allele. The exact mechanism of how HLA-A29 contributes to the disease is not fully understood, but it is believed that it may present a peptide that triggers an autoimmune response, leading to inflammation in the eye.

Genetic Diversity

HLA-A29 is relatively rare in the general population, with a frequency of less than 5%. It is most common in individuals of European descent. There are two main subtypes of HLA-A29, known as HLA-A*29:01 and HLA-A*29:02. These subtypes differ by only a few amino acids, but these differences can have significant effects on the peptides that the molecule can present.

See Also

• HLA-A
• Birdshot chorioretinopathy
• Major histocompatibility complex
• Autoimmune disease

References

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