title: Complement phenotypes in patients with psoriasis.
abstract: Phenotype frequencies for the complement proteins C4A, C4B, Bf (factor B) and C3 were performed for 49 Caucasian patients with psoriasis. The C4*A6 allele was present in 26.6% of the patients as compared to 5.4% of healthy regional Caucasian controls, p less than 0.001, relative risk = 6.28. The C4*A6 allele is known to be in linkage disequilibrium with the HLA B17 allele and to produce a non-functional gene product when it occurs with the B17 allele. HLA B17 is known to be associated with psoriasis in many Caucasian populations. Additional findings in the present study were a significant reduction in the C4B*2 allele frequency, a non-significant increase in the Bf*F allele frequency and no difference for Bf or C3 phenotype frequencies in the patients with psoriasis as compared to the controls.
authors.affiliation: Department of Pediatrics, University of Tennessee, Memphis.
authors.forename: R J
authors.initials: RJ
authors.lastname: Wyatt
authors.forename: C
authors.initials: C
authors.lastname: Wang
authors.forename: E C
authors.initials: EC
authors.lastname: Hudson
authors.forename: R M
authors.initials: RM
authors.lastname: Jones
authors.forename: P W
authors.initials: PW
authors.lastname: Noah
authors.forename: E W
authors.initials: EW
authors.lastname: Rosenberg
mesh_terms: D003176:Complement C3 / Q000235:genetics; D003181:Complement C4 / Q000235:genetics; D015934:Complement C4a / Q000235:genetics; D015935:Complement C4b / Q000235:genetics; D011415:Complement Factor B / Q000235:genetics; D003165:Complement System Proteins / Q000235:genetics*; D005787:Gene Frequency; D006801:Humans; D010641:Phenotype; D011565:Psoriasis / Q000235:genetics*; D044465:White People
chemical_list: D003176:Complement C3; D003181:Complement C4; D015934:Complement C4a; D015935:Complement C4b; D003165:Complement System Proteins; D011415:Complement Factor B