Brusco A, Boccazzi C, Plebani A, DeLange G G, Depelchin S, Carbonara A O
Dipartimento di Genetica Biologia e Chimica Medica e Centro CNR CII-CIOS, Turin, Italy.
Int J Clin Lab Res. 1995;25(3):165-8. doi: 10.1007/BF02592561.
The immunoglobulin heavy chain constant region locus is a multigene family composed of nine genes and two pseudogenes, whose high homology is often responsible for meiotic mispairings leading to deleted and duplicated haplotypes. These rearrangements have a population frequency of about 1.5% and 4.5% respectively, with a significant difference between deletions and duplications (P < 0.001). Both positive selection of duplications or negative selection against deletions can account for this imbalance. Serum levels of IgG and IgA subclasses, of IgE, of isohemagglutinins and of IgG antibodies to tetanus toxoid and pneumococcal antigens were evaluated in 11 heterozygous carriers of constant region deletions. There was no gross abnormality in serum IgG and IgA subclass levels, with the possible exception of G1-deleted individuals; furthermore, isohemagglutinins and anti-tetanus toxoid and pneumococcal IgG antibodies are in the normal range, suggesting that the humoral immune response is normal in these carriers. The influence of single and multiple immunoglobulin heavy chain constant region gene deletions on the humoral response is discussed.
免疫球蛋白重链恒定区基因座是一个由九个基因和两个假基因组成的多基因家族，其高度同源性常常导致减数分裂错配，进而产生缺失和重复的单倍型。这些重排的群体频率分别约为1.5%和4.5%，缺失和重复之间存在显著差异（P < 0.001）。重复的正向选择或缺失的负向选择都可以解释这种不平衡。对11名恒定区缺失的杂合携带者的血清IgG和IgA亚类、IgE、同种血凝素以及破伤风类毒素和肺炎球菌抗原的IgG抗体水平进行了评估。血清IgG和IgA亚类水平没有明显异常，G1缺失个体可能除外；此外，同种血凝素以及抗破伤风类毒素和肺炎球菌的IgG抗体在正常范围内，这表明这些携带者的体液免疫反应正常。本文讨论了单个和多个免疫球蛋白重链恒定区基因缺失对体液反应的影响。
