How do you calculate HLA allele frequency?
The allele frequencies were calculated by estimating the total number of copies of alleles (a) and the number of subjects (n) in each group of populations and using the formula, AF = a/2n.
How many HLA-A alleles are there?
For humans, as in most mammalian populations, MHC Class I molecules are extremely variable in their primary structure, and HLA-A is ranked among the genes in humans with the fastest-evolving coding sequence. As of December 2013, there are 2432 known HLA-A alleles coding for 1740 active proteins and 117 null proteins.
What are the most common HLA alleles?
The most common alleles found in Caucasians were HLA-A*02, 24, 01; HLA-B*35, 44, 51; DRB1*11, 13, 07; for Afro-Brazilians they were HLA-A*02, 03, 30; HLA-B*35, 15, 44; DRB1*13, 11, 03; and for Asians they were: HLA-A*24, 02, 26; HLA-B*40, 51, 52; DRB1*04, 15, 09.
What is HLA allele?
HLA genes are highly polymorphic, which means that they have many different alleles, allowing them to fine-tune the adaptive immune system. The proteins encoded by certain genes are also known as antigens, as a result of their historic discovery as factors in organ transplants.
What is the HLA region?
The MHC, also known in humans as the human leukocyte antigen (HLA) region, encompasses 7.6Mb on chromosome 6p21 and is the most gene dense region within the human genome encoding 252 expressed loci [3] including several key immune response genes.
How do I check my HLA?
How HLA testing is done. A sample of blood is taken by inserting a needle into a vein in your arm. Sometimes a swab of cells is taken from inside of your cheek (called a buccal swab) for testing. No special preparation is needed for either method.
What does HLA positive mean?
A positive result means HLA-B27 was found in your blood. You may have a higher-than-average risk of certain autoimmune diseases, such as ankylosing spondylitis and reactive arthritis.
Is HLA-A gene?
HLA is the human version of the major histocompatibility complex (MHC), a gene family that occurs in many species. Genes in this complex are categorized into three basic groups: class I, class II, and class III. In humans, the HLA-B gene and two related genes, HLA-A and HLA-C, are the main genes in MHC class I.
How common is HLA?
It is present in only 1.4-8% of the general population (higher in certain Native American groups and Scandinavians). Of patients with acute anterior uveitis, 50-60% may be HLA-B27 positive. Both racial background and national origin affect this rate of incidence.
How many HLA haplotypes are there?
There are three general groups of HLA, they are HLA-A,HLA-B and HLA-DR. There are many different specific HLA proteins within each of these three groups. (For example, there are 59 different HLA-A proteins, 118 different HLA-B and 124 different HLA-DR!)
Who needs HLA platelets?
HLA-matched platelets are indicated for patients that have thrombocytopenia and have demonstrated CCI values consistent with immune refractory thrombocytopenia on at least two occasions.
What diseases are associated with HLA?
Molecular interaction: MHC-peptides and autoimmune diseases
- Rheumatoid arthritis (RA)
- Multiple sclerosis (MS)
- Systemic lupus erythematosus (SLE)
- Type 1 diabetes mellitus (T1D)
- Sjögren’s syndrome (SS)
- Celiac disease (CD)
- Ankylosing spondylitis (AS)