2003年SARS在全球爆发时，不同的个体在感染后表现出不同的病程和最终的治疗结果，这被认为是个体本身的遗传因素在这个过程中起了一定的作用，即不同个体在一些基因上的多态影响了他们对一些疾病的易感性。CD209L基因是19号染色体上C型凝集素家族中的一员，它被证明是SARS病毒的受体，并且它的第4外显子的VNTR多态被认为和宿主对病毒的易感性有关。但是这个结论在其后其他两个研究小组的工作未被得到证实。
为了深入探讨这个问题，在中国科学院昆明动物研究所-香港中文大学生物资源与疾病分子机理联合实验室张亚平院士和邓亮生教授的共同指导下，博士生李慧等对19号染色体上C型凝集素家族的4个成员(FCER2， CLEC4G， CD209 和 CD209L)作了全面的研究，采用检测tagSNPs的方法，在C型凝集素家族基因簇上选取了23个tagSNPs位点来代表这个基因簇的多态。检测了来自中国香港的181个SARS病人和172个匹配的正常对照，结果表明C型凝集素家族的4个基因与中国南方汉族群体对SARS病毒的易感之间没有相关性。同时检测了来自中国不同地区的1145个汉族样本CD209L基因VNTR的多态分布情况，结果表明这个位点在中国人群中存在群体分层现象，提示之前的研究小组可能得到了假阳性结果，主要原因可能正是由于他们忽略了这个问题。
该研究成果发表于《医学遗传学杂志》（Journal of Medical Genetics）上。（生物谷Bioon.com）
生物谷推荐原始出处：
Journal of Medical Genetics，doi:10.1136/jmg.2008.058966，Hui Li，Ya-Ping Zhang
Polymorphisms in the C-type Lectin Genes Cluster in Chromosome 19 and Predisposition to SARS-Coronavirus Infection
Hui Li 1, Nelson L S Tang 2 and Ya-Ping Zhang 1*
1 Kunming Institue of Zoology, CAS, China
2 The Chinese University of Hong Kong, Hong Kong
Polymorphisms of CLEC4M had been associated with predisposition for infection by the SAR-CoV virus. DC-SIGNR, a C-type lectin encoded by CLEC4M, is a receptor for the virus. A VNTR polymorphism in its neck region was recently associated with susceptibility to SARS infection. However, this association was controversial and was not supported by subsequent studies. Two explanations may account for this discrepancy: (1) there may be an unknown predisposition polymorphism located in the proximity which is linked to the VNTR, or (2) it was a spurious association due to unrecognized population structure in the VNTR. We performed a comprehensively genetic association study on this C-type lectin gene cluster (FCER2, CLEC4G, CD209, and CLEC4M) at 19p13.3 by a tagging SNPs approach. 23 tagSNPs were genotyped in 181 SARS patients and 172 population controls. No significant association with disease predisposition was detected. Genetic variations in this cluster also did not predict disease prognosis. But we detected a population stratification of the VNTR alleles in a sample of 1145 Han Chinese collected from different part of China. The results indicated that genetic predisposition allele was not found in this lectin gene cluster and population stratification might cause the previous positive association.
