People with two copies of a certain version of a receptor (R131) are more likely to get lupus because that version doesn’t grab onto certain antibodies as well, leading to poor clearance of immune complexes.
Scientific Claim
The FcγRIIA R131 allele binds IgG2 with lower affinity than the H131 allele, and homozygosity for R/R131 is associated with increased susceptibility to systemic lupus erythematosus.
Original Statement
“For FcγRIIA, two co-dominantly expressed versions have been identified, R131 and H131, with the 131-Arg (R131) allele binding IgG2 much less avidity than the 131-His (H131) allele (132). Only the homozygous expression of the R/R131 variant has been associated with increased susceptibility of SLE and earlier onset (133, 134).”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
definitive
Can make definitive causal claims
Assessment Explanation
The claim reports a well-replicated genetic association from human epidemiological studies. The language 'associated with' is appropriately used and matches the cited evidence.
Evidence from Studies
Supporting (0)
Contradicting (1)
This study talks generally about how certain immune proteins might be involved in lupus, but it doesn’t mention the specific version of the protein (R131 vs. H131) or show that one binds IgG2 worse or causes more lupus.