HLA-A23

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HLA-A23 is a specific allele of the HLA-A gene, which is part of the human leukocyte antigen (HLA) system. The HLA system plays a crucial role in the immune system by helping the body distinguish between its own proteins and those made by foreign invaders such as viruses and bacteria.

Genetics

The HLA-A23 allele is one of the many variants of the HLA-A gene, located on the short arm of chromosome 6 at position 6p21.3. The HLA-A gene is part of the major histocompatibility complex (MHC) class I molecules, which present peptide fragments derived from intracellular proteins to cytotoxic T cells.

Function

HLA-A23, like other HLA-A alleles, encodes a protein that is expressed on the surface of almost all nucleated cells. This protein binds to peptide fragments from the cell's own proteins or from intracellular pathogens and presents them to T cells of the immune system. This process is essential for the immune system to recognize and respond to infected or malignant cells.

Clinical Significance

Certain HLA alleles, including HLA-A23, have been associated with various autoimmune diseases, infectious diseases, and transplant rejection. The presence of HLA-A23 can influence the outcome of organ transplantation and the body's response to certain infections.

Population Distribution

The frequency of the HLA-A23 allele varies among different populations. It is more commonly found in individuals of African descent and less frequently in other populations. Studies of HLA allele distribution can provide insights into population genetics and anthropology.

Related HLA Alleles

HLA-A23 is closely related to other HLA-A alleles, such as HLA-A24 and HLA-A25. These alleles share similar sequences and functions but differ in their peptide-binding specificities and population distributions.

See Also

• HLA-A
• Human leukocyte antigen
• Major histocompatibility complex
• Immune system
• Autoimmune disease
• Organ transplantation