检查 HFE基因突变应先检测C282Y和H63D多态性。当C282Y阴性而肝活检或MRI检查提示铁超载,同时排除肝脏和血液病时,应考虑检测和HFE有关的少见突变如转铁蛋白-2基因突变。[4]European Association For The Study Of The Liver. EASL clinical practice guidelines for HFE hemochromatosis. J Hepatol. 2010;53:3-22.http://www.journal-of-hepatology.eu/article/S0168-8278(10)00197-2/fulltexthttp://www.ncbi.nlm.nih.gov/pubmed/20471131?tool=bestpractice.com
C282Y基因突变纯合子是和北欧后裔血色病患者有关的最常见突变。在这一人群中,复杂杂合子(C282Y和H63D)可引起较轻的临床表现。H63D 纯合子极少和血色病的临床表型相关,只有存在共病时才明显。然而在其他人群中,H63D和其他诸如S65C基因突变,不管是纯合子还是复杂杂合子均与血色病相关。[6]Perez R, Toro D, Fournier J, et al. Prevalence of hemochromatosis in the Puerto Rico veteran population. P R Health Sci J. 2007;26:147-150.http://www.ncbi.nlm.nih.gov/pubmed/17722428?tool=bestpractice.com[7]Pietrangelo A. Hereditary hemochromatosis. Biochim Biophys Acta. 2006;1763:700-710.http://www.ncbi.nlm.nih.gov/pubmed/16891003?tool=bestpractice.com[8]Terzic R, Sehic A, Teran N, et al. Frequency of HFE gene mutations C282Y and H63D in Bosnia and Herzegovina. Coll Antropol. 2006;30:555-557.http://www.ncbi.nlm.nih.gov/pubmed/17058523?tool=bestpractice.com[9]Cimburova M, Putova I, Provaznikova H, et al. S65C and other mutations in the haemochromatosis gene in the Czech population. Folia Biol (Praha). 2005;51:172-176.http://fb.cuni.cz/Data/files/folia_biologica/volume_51_2005_6/FB2005A0030.pdfhttp://www.ncbi.nlm.nih.gov/pubmed/16419611?tool=bestpractice.com[10]Leone PE, Gimenez P, Collantes JC, et al. Analysis of HFE gene mutations (C282Y, H63D, and S65C) in the Ecuadorian population. Ann Hematol. 2005;84:103-105.http://www.ncbi.nlm.nih.gov/pubmed/15517265?tool=bestpractice.com[11]Scotet V, Le Gac G, Mérour MC, et al. Impact of HFE genetic testing on clinical presentation of hereditary hemochromatosis: new epidemiological data. BMC Med Genet. 2005;6:24.http://bmcmedgenet.biomedcentral.com/articles/10.1186/1471-2350-6-24http://www.ncbi.nlm.nih.gov/pubmed/15929798?tool=bestpractice.com[12]Pardo A, Quintero E, Barrios Y, et al. Genotype and phenotypic expression of hereditary hemochromatosis in Spain [in Spanish]. Gastroenterol Hepatol 2004;27:437-443.http://www.ncbi.nlm.nih.gov/pubmed/15388046?tool=bestpractice.com[13]Sassi R, Hmida S, Kaabi H, et al. Prevalence of C282Y and H63D mutations in the haemochromatosis (HFE) gene in Tunisian population. Ann Genet. 2004;47:325-330.http://www.ncbi.nlm.nih.gov/pubmed/15581829?tool=bestpractice.com[14]Wrede CE, Hutzler S, Bollheimer LC, et al. Correlation between iron status and genetic hemochromatosis (codon C282Y) in a large German population. Isr Med Assoc J. 2004;6:30-33.http://www.ima.org.il/FilesUpload/IMAJ/0/51/25891.pdfhttp://www.ncbi.nlm.nih.gov/pubmed/14740507?tool=bestpractice.com[15]Milman N, Pedersen P, Steig T, et al. Frequencies of the hereditary hemochromatosis allele in different populations: comparison of previous phenotypic methods and novel genotypic methods. Int J Hematol. 2003;77:48-54.http://www.ncbi.nlm.nih.gov/pubmed/12568299?tool=bestpractice.com[33]Potekhina ES, Lavrov AV, Samokhodskaya LM, et al. Unique genetic profile of hereditary hemochromatosis in Russians: high frequency of C282Y mutation in population, but not in patients. Blood Cells Mol Dis. 2005;35:182-188.http://www.ncbi.nlm.nih.gov/pubmed/16055358?tool=bestpractice.com
实际上,单一基因突变的杂合子不会引起临床症状。寻找血色病罕见病因(如铁调素基因突变)是否有价值尚待明确,临床实验室不常规提供这样的检测。