Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0032285 (pneumonia)
 54,520 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The functional single nucleotide polymorphism rs1801274 in the FCGR2A gene (His131Arg) influences the efficiency of hIgG2 binding, the main isotype produced in response to encapsulated bacteria like Streptococcus pneumoniae and Haemophilus influenzae. In contrast to the receptor with the His131 allele, FcgammaRIIa-Arg131 binds hIgG2 poorly and carriers of this variant have been shown to be much more susceptible to succumb to bacterial pneumonia or meningitis. As bacteraemic pneumonia is one of the leading causes of death in elderly individuals, we hypothesized that the Arg131 variant could be a major mortality factor in the old. We analysed the FCGR2A-His131Arg polymorphism in a group of 408 German centenarians and two samples of younger Germans aged 60-75 and 18-49 years, respectively. No statistically significant differences were observed between the three age groups, neither at the allele nor at the genotype level. Apparently, the ability to reach old age is largely unaffected by the genetically determined efficacy of the FCGR2A-based immune response. However, the severely reduced ability of FCGR2A-131Arg carriers to eliminate encapsulated bacteria must apparently be compensated by an alternative mechanism, possibly involving other genetic survival factors.
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PMID:The FCGR2A--Arg131 variant is no major mortality factor in the elderly--evidence from a German centenarian study. 1689 92

The A/H1N1 influenza strain isolated in Mexico in 2009 caused severe pulmonary illness in a small number of exposed individuals. Our objective was to determine the influence of genetic factors on their susceptibility. We carried out a case-control association study genotyping 91 patients with confirmed severe pneumonia from A/H1N1 infection and 98 exposed but asymptomatic household contacts, using the HumanCVD BeadChip (Illumina, San Diego, CA, USA). Four risk single-nucleotide polymorphisms were significantly (p<0.0001) associated with severe pneumonia: rs1801274 (Fc fragment of immunoglobulin G, low-affinity IIA, receptor (FCGR2A) gene, chromosome 1; OR 2.68, 95% CI 1.69-4.25); rs9856661 (gene unknown, chromosome 3; OR 2.62, 95% CI 1.64-4.18); rs8070740 (RPA interacting protein (RPAIN) gene, chromosome 17; OR 2.67, 95% CI 1.63-4.39); and rs3786054 (complement component 1, q subcomponent binding protein (C1QBP) gene, chromosome 17; OR 3.13, 95% CI 1.89-5.17). All SNP associations remained significant after adjustment for sex and comorbidities. The SNPs on chromosome 17 were in linkage disequilibrium. These findings revealed that gene polymorphisms located in chromosomes 1 and 17 might influence susceptibility to development of severe pneumonia in A/H1N1 infection. Two of these SNPs are mapped within genes (FCGR2A, C1QBP) involved in the handling of immune complexes and complement activation, respectively, suggesting that these genes may confer risk due to increased activation of host immunity.
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PMID:Genetic variants associated with severe pneumonia in A/H1N1 influenza infection. 2173 55