Marcelli-Barge A, Poirier J C, Chantome R, Deschamps I, Hors J, Colombani J
Laboratoire d'Immunologie et d'Histocompatibilité, Hôpital Saint-Louis, Paris, France.
Res Immunol. 1990 Feb;141(2):117-28. doi: 10.1016/0923-2494(90)90131-h.
TaqI, BamHI and HinddIII polymorphisms of the C4 genes were studied with a 500-bp C4 cDNA probe (pAT-A153) specific for the 5' end of the gene. The restriction patterns obtained were correlated with the C4A and C4B genotypes in 35 patients suffering from insulin-dependent diabetes mellitus (IDDM), and results were compared to those from 40 healthy individuals. The controls, all Caucasian, were genotyped for HLA-A, B, C, DR, Bf, C2 and C4, together with 10 diabetics and their families; haplotypes for the other patients had been deduced using DNA and protein polymorphism, and taking into consideration linkage disequilibrium for neighbouring loci. No significant difference between genotypes at the C4A locus was seen in either population. The C4A gene deletion, associated with a C4B "short" gene (66.7%), was found mainly in the haplotype B8,Cw7,DR3,BfS,C2C, C4AQOB1, and the C4B gene deletion in the haplotype B18,Cw5,DR3,BfF1, C2C,C4A3BQO. When diabetic patients were compared with normal individuals, we observed, at the C4B locus, a decrease in the C4B "long" gene (22% vs. 49% respectively, p less than 0.001). A compensatory increase was observed in patients vs. controls for the frequency of C4BQO, both in the deleted and intact form (26% vs. 10% respectively, p less than 0.03).
利用针对该基因5'端的500个碱基对的C4 cDNA探针（pAT - A153），研究了C4基因的TaqI、BamHI和HinddIII多态性。所获得的限制性酶切图谱与35例胰岛素依赖型糖尿病（IDDM）患者的C4A和C4B基因型相关，并将结果与40名健康个体的结果进行了比较。所有白种人的对照组，以及10名糖尿病患者及其家属，均对HLA - A、B、C、DR、Bf、C2和C4进行了基因分型；其他患者的单倍型是利用DNA和蛋白质多态性推导出来的，并考虑了相邻基因座的连锁不平衡。在任何一个群体中，C4A基因座的基因型之间均未观察到显著差异。与C4B“短”基因相关的C4A基因缺失（66.7%），主要见于单倍型B8、Cw7、DR3、BfS、C2C、C4AQOB1，而C4B基因缺失见于单倍型B18、Cw5、DR3、BfF1、C2C、C4A3BQO。当将糖尿病患者与正常个体进行比较时，我们发现在C4B基因座，C4B“长”基因减少（分别为22%对49%，p小于0.001）。在患者与对照组中，观察到C4BQO频率有代偿性增加，无论是缺失形式还是完整形式（分别为26%对10%，p小于0.03）。
