• Antigens
  • The proteins encoded by certain genes are also known as antigens, as a result of their historic discovery as factors in organ transplants. (wikipedia.org)
  • Immunogenetics emerged in the 1930s as the study of genes controlling antigens (such as those of the various blood group systems) detected by antibodies. (wikipedia.org)
  • The class I genes were discovered in 1936 (the year Jan Klein was born) as coding for blood group (red blood cell) antigens, which, however, were also responsible for the rejection of incompatible grafts. (wikipedia.org)
  • Klein, with his coworker Vera Hauptfeld and his wife Dagmar Klein, were the first to describe the product of the class II genes and identify them as the molecules that control level of antibodies synthesized in response to foreign antigens. (wikipedia.org)
  • genotypes
  • The five SNPs in three genes acted in additive fashion to increase the risk of AMD from less than 1 percent in people with the lowest-risk genotypes at each SNP, to more than 50 percent for those with five risky SNPs. (alzforum.org)
  • This model represents a case which there is a single locus where all genotypes may lead to expression of the allele in its most simplified definition. (wikipedia.org)
  • loci
  • DQ2 There are many other gene-alleles within the haplotype, including more than 250 coding loci that produce transcripts. (wikipedia.org)
  • The haplotype can be written in an extended form covering the major histocompatibility loci as follows: HLA Cw*0702 : B*0702 : DRB1*1501 : DQA1*0102 : DQB1*0602 The older literature may describe this haplotype in two different ways. (wikipedia.org)
  • The haplotype can be written in an extended form covering the major histocompatibility loci as follows: HLA A*01:01 : Cw*07:01 : B*08:01 However, there are many other gene-alleles within the haplotype. (wikipedia.org)
  • Our results show that dissection of complex disease susceptibility loci will be a challenging process and that identification of strongly associated alleles, even when they are protein coding, should not preclude further detailed genetic analysis," write Abecasis and Swaroop. (alzforum.org)
  • locus
  • The length of the haplotype is remarkable because of the rapid rate of evolution at the HLA locus should degrade such long haplotypes. (wikipedia.org)
  • In the US Caucasians, 57% of haplotypes with a core component, Cw7-B8, extend from HLA-A1 locus to DQ2 locus. (wikipedia.org)
  • Concordant results between studies of different ethnic groups serves to support the HLA association for both groups, and discordant results may mean that the allele is simply a marker for the actual locus, or that the different ethnic groups have different HLA disease susceptibility alleles. (chori.org)
  • Gene diversity per locus varied from 0.5788 (DYS388) to 0.8903 (DYS385a/b). (scirp.org)
  • The aHt haplotype has found a higher discriminatory potential than minHt haplotype with a better Pd combined value (0.9999936 vs 0.9999836) and has higher average gene diversity per locus (0.7834 vs 0.7518) in Turkish population. (scirp.org)
  • While type 1 diabetes shows an extended association on the HLA A1-B8-DR3-DQ2 haplotype, the association appears not to extend beyond the HLA-B locus. (wikipedia.org)
  • C4 (complement 4) produces a null allele at on locus C4AQ. (wikipedia.org)
  • This locus in part of the HLA A1-B8-DR3-DQ2 haplotype (markers are A1, CW7, B8, BfS, C4AQ0, C4B1, DR3, DQ2) therefore one study concluded that C4AQ0 could explain the increased infectivity to HIV. (wikipedia.org)
  • They also found two SNPs in a second complement-related locus, this one containing the gene for complement component 1 and complement factor B (C2/CFB). (alzforum.org)
  • For A1, the alpha "A" chain are encoded by the HLA-A*01 allele group and the β-chain are encoded by B2M locus. (wikipedia.org)
  • polymorphisms
  • Particular attention will be given to the role of AGT gene polymorphisms in the etiology of essential hypertension. (ahajournals.org)
  • In the second paper, from Goncalo Abecasis and Anand Swaroop of the University of Michigan at Ann Arbor, a similarly intensive survey of SNPs in the CFH gene in 762 affected people and 268 controls turned up 20 polymorphisms that showed stronger association than Y402H. (alzforum.org)
  • Alleles that change a gene's expression level without altering protein structure have been implicated in several other neurodegenerative diseases, revealing an increasing role for regulatory polymorphisms (see ARF related news story ). (alzforum.org)
  • To explore the genetic involvement of the eNOS gene in essential hypertension, we examined the possible association between essential hypertension and several polymorphisms including the Glu298Asp variant, variable number tandem repeats in intron 4 (eNOS4b/4a), and two polymorphisms in introns 18 and 23. (ahajournals.org)
  • 2000
  • 2000) observed that the haplotype is of likely paleo North African origin, and later studies of North Africa support that finding. (wikipedia.org)
  • populations
  • Multigene haplotypes following standard dynamics only exist in robust populations for a short time, the average distance between genes of about 200,000 nts, which means that over 250 generations (~5000 years) one expects 1/2 of adjacent genes to have new gene-alleles, unless the genes are small and very close together. (wikipedia.org)
  • Parts of the haplotype are spread into East Asia and even appear within the New world's indigeonous populations. (wikipedia.org)
  • 8 9 To further elucidate the genetic involvement of the eNOS gene in essential hypertension, we examined the possible association between the Glu298Asp variant and essential hypertension in two Japanese populations. (ahajournals.org)
  • DQ2.5
  • Although it cannot identify the alpha ".5" chain of HLA DQ, DQA1*0501 gene is almost always found within the DR3-DQ2 haplotype Eurasia (however is older studies DQA1*0505 is commonly confused with DQA1*0501) DR3 is genetically linked to HLA-DR52, DRB3*0202 allele, and HLA-DQ2 (DQ2.5). (wikipedia.org)
  • Other haplotypes such as Cw5-B16-DR3 or B8-DR3-DQ2.5 have been presented in the literature. (wikipedia.org)
  • SNPs
  • 8 Because the disease association of a SNP may depend on its cis interactions with other SNPs in a gene, we examined haplotypes in addition to individual SNPs. (ahajournals.org)
  • In the study from the Seddon group, first author Julian Maller worked together with Mark Daly and colleagues at the Broad Institute of Harvard and MIT to survey 1,536 SNPs over three genes in more than 2,000 people (1,238 affected individuals and 934 controls). (alzforum.org)
  • polymorphic
  • The class I cell surface heterodimer has one highly polymorphic alpha chain, with variable residues clustering within the peptide binding cleft, which is encoded by exons 2 and 3 of the gene. (chori.org)
  • In class II molecules, the beta chain contains the highly polymorphic regions, which are localized to exon 2 of the gene and encode the peptide-binding cleft. (chori.org)
  • The HLA genes are the most polymorphic in the genome. (chori.org)
  • HLA genes are highly polymorphic, which means that they have many different alleles, allowing them to fine-tune the adaptive immune system. (wikipedia.org)
  • diseases
  • Also a dozen inflammatory diseases of the immune system can attribute some risk to the haplotype. (wikipedia.org)
  • While other diseases, like type 1 diabetes may have several, highly different, genes that attribute risk. (wikipedia.org)
  • Today however the collection of genes is associated with increased incidences of certain diseases. (wikipedia.org)
  • In at least 2 diseases, the risk of autoimmune disease extends beyond the class II region of the haplotype. (wikipedia.org)
  • Determining genetic risk is an exceedingly complicated proposition, the study indicates, and finding all the risk alleles for common diseases will likely involve a thorough analysis of hundreds or thousands of cases. (alzforum.org)
  • A1-B58 haplotype (A1-B17 where B58 is dominant) may remain associated with anti-neutrophil cytoplasmic antibody (ANCA) With the exception of type 1 diabetes, most of the evidence for direct association of A1 with autoimmune diseases evaporated as DR3 and DQ2 genes were characterized. (wikipedia.org)
  • Some diseases found associated with A1 actually link to the extended A1-B8 haplotype, viral induced hepatitis and accelerated progression of HIV are examples. (wikipedia.org)
  • humans
  • 7 Whether genetic variation in the B2AR gene is associated with SCD risk in humans has not previously been explored. (ahajournals.org)
  • The human leukocyte antigen (HLA) system or complex is a gene complex encoding the major histocompatibility complex (MHC) proteins in humans. (wikipedia.org)
  • descent
  • None of the patients had mutations of the lipoprotein lipase gene common in subjects of French-Canadian descent. (ahajournals.org)
  • 0501
  • Cw5-B18 The Cw5-B18 (Cw*0501:B*1801) appears to be the oldest portion of the haplotype, as it is found below the sahel in the rainforest dwelling peoples of Cameroon and it is also found in the Nikoholo Mandenka. (wikipedia.org)
  • Levels of B18-DR3 in Europe appear to be combinations of the Cw*0501 and Cw*1201 haplotype. (wikipedia.org)
  • found
  • DQ2 is the most frequent haplotype of its length found in US Caucasians, ~15% carry this common haplotype. (wikipedia.org)
  • This haplotype if found often in Northern Spain, Switzerland, Netherlands. (wikipedia.org)
  • The CwB haplotype peaks in Sardinia along with the rest of the haplotype and can be found in high resolution studies of the S. Irish, N. Irish, UK Caucasoids, and French. (wikipedia.org)
  • In Europe A1-B8 is found, generally as part of the HLA A1-B8-DR3-DQ2 haplotype. (wikipedia.org)
  • A recent study of DR3-DQ2/DR4-DQ8 phenotype found that A1-cw7-B8 was actually lower than expected relative to other A-B types, indicating that risk associated genes are located between B8 and DR3. (wikipedia.org)
  • Unexpectedly, the strongest disease association they found within the CFH gene was not the previously observed Y402H SNP, but an intronic SNP that did not affect protein sequence. (alzforum.org)
  • One haplotype A3-B7-DR15-DQ1 can be found over a vast region and is in apparent selective disequilibrium. (wikipedia.org)
  • In persistent sarcoidosis this haplotype was found to be increased in sarcoidosis, and further study eliminated risk contributed by A3-Cw7 and DQ6.2 indicating B7-DR15 haplotype contains risk of disease (OR = 2.5). (wikipedia.org)
  • In Croatian children, two HLA-B27 alleles were found associated with disease, B*2702, B*2705. (wikipedia.org)
  • B*2705 was found to be dominant allele associated. (wikipedia.org)
  • A more recent study looked at a number of linked gene-alleles and found I82-2:D6S265-1:HLA-A3:D6S128-2:HLA-F1:D6S105-8 was constantly associated while B7 appeared beyond the haplotype linked to disease. (wikipedia.org)
  • The B53 sequence is identical to B35 but short sequence specifies a Bw4 rather than a Bw6 motif (as found in B35), indicating B53 is a recent product of gene conversion. (wikipedia.org)
  • variants
  • To investigate whether functional variants of the B2AR gene influence SCD risk, we genotyped 5249 elderly individuals who were followed up prospectively to identify SCD events. (ahajournals.org)
  • In Africa A1-B8 and India A1-B8 is associated with other genes and other variants of A*01 and B*08 Philosophically, A1-B8 is more than just two gene-alleles. (wikipedia.org)
  • In two papers in the August 27 online edition of Nature Genetics, researchers report finding additional CFH sequence variants that are even more strongly associated with the risk of AMD than the Y402H allele. (alzforum.org)
  • One of the papers, from a group of Boston researchers led by Johanna Seddon at the Massachusetts Eye and Ear Infirmary, also confirms variants in two other genes that act additively with CFH to determine the risk of AMD in individuals. (alzforum.org)
  • adaptive immune
  • In the adaptive immune system, the three preeminent sets of genes are those that code for the Mhc, T-cell receptor (Tcr), and B-cell receptor (Bcr, the antibodies) proteins. (wikipedia.org)
  • common
  • Therefore, 3 common haplotypes exist: H1 (Gly16-Glu27), H2 (Arg16-Gln27), and H3 (Gly16-Gln27). (ahajournals.org)
  • A1 is more common in Europe than elsewhere, it is part of a long haplotype that appears to have been frequent in the ancient peoples of Northwestern Europe. (wikipedia.org)
  • In Klein's conception, immunogenetics was to deal with what immunology and genetics have in common-a set of genes that control and effect immune responses of any kind. (wikipedia.org)
  • genetic
  • Study of genetic variation within the B2AR gene may help identify those at increased SCD risk. (ahajournals.org)
  • Genetic Epidemiol 6:127-130 Knapp,Seuchter,Baur (1987) "The haplotype-relative-risk" (HRR) method for analysis of association in nuclear families. (wikipedia.org)
  • sequence
  • They call for careful studies not just of SNP association, but of regional DNA sequence and gene expression patterns to get a full understanding of the contribution of the CFH gene. (alzforum.org)
  • Sequence analysis of the promoter region of the apo AI gene reveals heterozygosity for guanine-to-adenine substitution at position 76 in two kindreds with no evidence of segregation with the low HDL trait. (ahajournals.org)
  • This suggests an origin for HLA-B53 involving a gene conversion of HLA-B35 by an allele containing this Bw4 sequence. (wikipedia.org)
  • disease
  • Some disease like coeliac disease primarily associate with certain genes. (wikipedia.org)
  • This disequilibrium made it appear that A1 and other class I gene-alleles were disease factors, when these alleles were only attached to a long segment of conserved DNA that had disease associated genes on the other end. (wikipedia.org)
  • suggests
  • Accumulating evidence, including findings of elevation of arterial blood pressure in mice lacking the endothelial nitric oxide synthase (eNOS) gene, strongly suggests that alteration in NO metabolism is implicated in hypertension. (ahajournals.org)
  • Protein
  • We will begin by describing the basics of the AGT gene and protein, followed by some of the known physiological roles of the classical and tissue renin-angiotensin system (RAS) in blood pressure regulation. (ahajournals.org)
  • major
  • Aside from the genes encoding the 6 major antigen-presenting proteins, there are a large number of other genes, many involved in immune function, located on the HLA complex. (wikipedia.org)
  • His major research focus was on the major histocompatibility complex, (MHC or Mhc), which comprises series of genes, which play a critical part in the initiation of the adaptive immune response (AIS), exemplified by the production of antibodies specific for different pathogens. (wikipedia.org)
  • class
  • Sarcoidosis and human leukocyte antigen class I and II genes: it takes two to tango? (wikipedia.org)
  • He developed the modern concept of the Mhc as consisting of two principal kinds of gene, for which he coined the designations class I and class II genes. (wikipedia.org)
  • exon
  • We have identified a missense variant, Glu298Asp, in exon 7 of the eNOS gene and demonstrated that it is associated with both coronary spastic angina and myocardial infarction. (ahajournals.org)
  • We recently identified another variant of the eNOS gene within exon 7: G to T conversion at nucleotide position 894 of eNOS cDNA resulting in a replacement of glutamic acid by aspartic acid at codon 298 (Glu298Asp). (ahajournals.org)
  • Association
  • In this review, we will revisit the evidence supporting or refuting an association of the angiotensinogen (AGT) gene with hypertension. (ahajournals.org)
  • The A1-B8-DR3-DQ2 haplotype has a known association with Enteropathy-associated T-cell lymphoma, approximately 70% of patients are homozygotes for DQ2 with at least one copy of DR3-DQ2. (wikipedia.org)
  • study
  • 2 A recent study using mice with disrupted eNOS gene revealed that eNOS function is required for vascular and hemodynamic responses to acetylcholine and that the disruption of the eNOS gene leads to hypertension. (ahajournals.org)
  • long
  • This dynamic can change if the population expands rapidly from a few individuals that lived in isolation as long as other haplotypes are maintained. (wikipedia.org)