The 22q11.2 deletion syndrome (22q11.2 del), also known as DiGeorge syndrome, is a genetic disorder with an estimated incidence of 1:3000 to 1:6000 births. These patients may suffer from affection of many organ systems with cardiac malformations, immunodeficiency, hypoparathyroidism, autoimmunity, palate anomalies, and psychiatric disorders being the most frequent. The importance of the complement system in 22q11.2 del has not been investigated. The objective of this study was to evaluate the complement system in relation to clinical and immunological parameters in patients. A national cohort of patients (n = 69) with a proven heterozygous deletion of chromosome 22q11.2 and a group of age and sex matched controls (n = 56) were studied. Functional capacity of the classical, lectin, and alternative pathways of the complement system as well as complement activation products C3bc and terminal complement complex (TCC) were accessed and correlated to clinical features. All patients in our study had normal complement activation in both classical and alternative pathways. The frequency of mannose-binding lectin deficiency was comparable to the normal population. The patients had significantly raised plasma levels of C3bc and a slight, but not significant, increase in TCC compared with controls. This increase was associated with the presence of psychiatric disorders in patients. The present study shows no complement deficiencies in 22q11.2 deletion syndrome. On the contrary, there are signs of increased complement activation in these patients. Complement activation is particularly associated with the presence of psychiatric disorders.

22q11.2 缺失综合征 (22q11.2 del)，也称为 DiGeorge 综合征，是一种遗传性疾病，估计出生率为 1:3000 至 1:6000。这些患者可能患有心脏畸形、免疫缺陷、甲状旁腺功能减退、自身免疫、腭异常和最常见的精神疾病的许多器官系统。尚未研究补体系统在 22q11.2 del 中的重要性。本研究的目的是评估补体系统与患者临床和免疫学参数的关系。一个国家队列 ( n  = 69) 证实了染色体 22q11.2 杂合缺失和一组年龄和性别匹配的对照 ( n = 56) 进行了研究。研究了补体系统的经典、凝集素和替代途径以及补体激活产物 C3bc 和终末补体复合物 (TCC) 的功能能力，并将其与临床特征相关联。我们研究中的所有患者在经典和替代途径中都有正常的补体激活。甘露糖结合凝集素缺乏的频率与正常人群相当。与对照组相比，患者的血浆 C3bc 水平显着升高，TCC 略有但不显着增加。这种增加与患者存在精神障碍有关。本研究显示 22q11.2 缺失综合征没有补体缺陷。相反，在这些患者中有补体激活增加的迹象。