title: HLA-linked C2 deficiency in a Dutch patient with systemic lupus erythematosus.
abstract: A patient with systemic lupus erythematosus was studied whose blood serum on repeated occasions showed undetectable levels of haemolytic omplement (C). A detailed investigation of individual C components in the serum of the proposita and her family revealed the absence of functional C2 in the patient and half-normal values in the relatives. C4 levels in the family, but not in the patient, were above normal, whereas the levels of factor B were low in all cases. No abnormalities were noted in C3, C9, or C1INH. Tissue typing showed linkage of the C2-deficiency gene with the HLA-A10/B18 and A9/B18 haplotypes. No linkage with red cell antigens and no relationship with plasma kallikrein levels was found.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001789:Blood Group Antigens; D003175:Complement C2 / Q000172:deficiency* / Q000235:genetics; D005260:Female; D006680:HLA Antigens / Q000032:analysis / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000235:genetics / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010375:Pedigree
chemical_list: D001789:Blood Group Antigens; D003175:Complement C2; D006680:HLA Antigens