[The C5 gene polymorphism in patients with PNH]
Jun-Ichi Nishimura1, Yuzuru Kanakura
1Osaka University Graduate School of Medicine, Department of Hematology and Oncology.
Abstract:
This review is a commentary on an article entitled "Genetic variants in C5 and poor response to eculizumab" (N Engl J Med. 2014; 370: 632-639). The molecular basis for the poor response to eculizumab in Japanese patients is unclear. Of 345 Japanese patients with paroxysmal nocturnal hemoglobinuria (PNH) who received eculizumab, 11 showed a poor response. All 11 had a single missense C5 heterozygous mutation, c.2654 G>A, which predicts the polymorphism p.Arg885His. The prevalence of this mutation among patients with PNH (3.2%) was similar to that in healthy Japanese persons (3.5%). This polymorphism was also identified in a Han Chinese population. Non-mutant and mutant C5 both caused hemolysis in vitro, but only non-mutant C5 bound to and was blocked by eculizumab. In vitro hemolysis due to non-mutant and mutant C5 was completely blocked by N19-8, a monoclonal antibody that binds to a different site on C5 than does eculizumab. The functional capacity of the C5 polymorphism p.Arg885His, together with its failure to undergo blockade by eculizumab, accounts for the poor response to this agent in patients who carry this mutation.
More Related Videos
06:21Author Spotlight: Genetic Profiling for Fluorouracil Response in Gastric Cancer
Published on: May 10, 2024
08:22A Novel Strategy Combining Array-CGH, Whole-exome Sequencing and In Utero Electroporation in Rodents to Identify Causative Genes for Brain Malformations
Published on: December 1, 2017
Related Concept Videos
Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu
Comparing Copy Number Variations and SNPs
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes
Single Nucleotide Polymorphisms-SNPs
Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
