Unidad de Inmunología Hospital Universitario La Paz and Hospital La Paz Health Research Institute (IdiPAZ), Madrid, Spain.
Orphanet J Rare Dis. 2012 Jun 18;7:42. doi: 10.1186/1750-1172-7-42.
Complement Factor I (CFI) is a serine protease with an important role in complement alternative pathway regulation. Complete factor I deficiency is strongly associated with severe infections. Approximately 30 families with this deficiency have been described worldwide.
We have studied five new Spanish families suffering from CFI deficiency. From 19 screened people, 7 homozygous, 10 heterozygous and 2 healthy subjects were identified. Clinical, biochemical and genetic descriptions are included.
Molecular studies demonstrated 4 novel mutations in the screened individuals; amongst them, we describe here the first great gene deletion reported in the CFI locus, which includes full exon 2 and part of the large intron 1.
CFI deficiency is possibly an underestimated defect and the eventual existence of this deficiency should be tested in those patients exhibiting low C3 and recurrent bacterial infections. We propose a simple diagnostic flowchart to help clinicians in the identification and correct diagnosis of such patients.
补体因子 I（CFI）是一种丝氨酸蛋白酶，在补体替代途径的调节中具有重要作用。完全缺乏因子 I 与严重感染密切相关。全世界已经描述了大约 30 个具有这种缺陷的家族。
我们研究了五个来自西班牙的患有 CFI 缺陷的新家族。在筛选出的 19 人中，发现 7 名纯合子、10 名杂合子和 2 名健康个体。包括临床、生化和遗传描述。
分子研究在筛选出的个体中发现了 4 个新的突变；其中，我们在这里描述了 CFI 基因座中首次报道的大基因缺失，该缺失包括完整的外显子 2 和部分大内含子 1。
CFI 缺陷可能是一个被低估的缺陷，最终应该在那些表现出低 C3 和反复细菌感染的患者中检测到这种缺陷的存在。我们提出了一个简单的诊断流程图，以帮助临床医生识别和正确诊断这些患者。
