简介：Theaimofthisstudywastoanalyzethepointmutationoftheexon1atcodon54ofthemannose(ormannan)-bindinglectin(MBL)geneinhealthyindividualsofChineseHansandMongolianpopulation,andtofindoutanyassociationbetweentheplasmalevelsofMBLandthegenemutationfrequencyinbethgroupsofindividuals.Bloodsampleswerecollectedrandomlyfrom56healthyindividualsofChineseHansand37Mongolian.ThedetectionofthepointmutationsoftheMBLgenewasperformedbypolymerasechainreaction-restrictionfragmentlengthpolymorphism(PCR-RFLP)anddetectionsforplasmalevelsofMBLweredeterminedbyusingMBLELISAkits.AMBLPCRmethodofassaywasestablishedwithhighspecificity,andgoodreproducibility.ByoptimizingthePCRcondition,theoptimalannealingtemperaturewas55℃,andthelowestdetec-tionlimitwas160pg.Nobandswerefoundinnon-specificitysamples(HAV,HBV,HCVandTB),andthesequencesofPCRproductswerethesameastheexpectedones.AlsoaMBLPCR-RFIPwasestablished.Uponelectrophoresisofthedigestedproductsin3%agarosegel,therewere3patterns:inwhich2bandscorrespondtomoleculeweight232bpand93bp;1band,correspondstomoleculeweight325bpand3bandscorrespondtomoleculeweight325bp,232bpand93bp,respectively.Threebandsof325bp,232bpand93bpofpointmutationswerefoundatcedon54ofMBLcedinggene.FrequenciesinhealthyHanandMongolianpopulationwere0.2321and0.1757respectively.TheaverageplasmaMBLconcentrationwas1998.750μg/L,withSDof1505.152in56healthyHanpopulationand2525.676μg/L,withSDof1955.188in37Mongolian.AnegativecorrelationbetweenMBLconcentrationandgenemutationfrequencywasfoundinhealthyHanpopulation.Frequencyofpointmutationwas1.00whentheMBLconcentrationswerebelow100μg/L;frequencyofpointmutationwas0.4524whentheconcentrationwas100μg/Lto1000μg/L;andthefrequencyofpointmutationwas0.0156whentheconcentrationwaso