FcγRIIa Genotyping
Overview
FcγRIIa genotyping identifies the R131H single nucleotide polymorphism in the FcγRIIa gene, yielding three genotypes: HH, HR, and RR. The assay uses nested PCR to amplify a ~1 kb region spanning exons 4–5 of the FcγRIIa gene. Outer primers (P63 sense, FcγRII-30 antisense) are followed by allele-specific inner sense primers — 494A (for Arg/R131) and 494G (for His/H131) — with P52 as the common antisense primer. Products are resolved by agarose gel electrophoresis. Genomic DNA is extracted from whole blood.
Key Points from Literature
- Used in Garcia2009 - Long-term Clinical Symptoms Post-Dengue to genotype 97 dengue patients; the HH genotype was significantly associated with persistent post-dengue symptoms vs HR+RR combined (p = 0.027; OR 2.83).
- Used in Garcia2010 - Asymptomatic Dengue FcγRIIa Polymorphism with the identical protocol to genotype 139 individuals (68 DF, 29 DHF/DSS, 42 asymptomatic); HH frequency was 51.5% in DHF, 39.4% in DF, and only 9.1% in asymptomatic individuals (p = 0.008); RR was protective against DHF (OR 0.09).
- Protocol follows Bazilio et al. (2004), developed originally in the context of lupus nephritis susceptibility.
Contradictions & Debates
None yet recorded.