dnophenocopy.
dentinogenesisimperfectatypeiiisanautosomaldominantdisorderofdentinformationandmineralization.recently,thecriticalregionhasbeennarrowedfromthe6.6cmd4s2691-d4s2692intervaltothe2.0mbgata2a11-d4s1563intervalathumanchromosome4q21.inthecurrentinvestigation,fiveexteivechinesedgi-iipedigreeswerecollected.linkageanalysiswithstrpat4q21regionhasfurtherrefinedthecandidateregiontoa800kbinterval.theresultsofthemutation-screeningaaywithpcr-cpandsequenceofdgenehavedemotratedthatagtoatraitionwasdetectedinthedonorlicesite(gt)ofintron3inhypedigree.innjfamilyallaffectedmemberscarryaccatoacatraversionatcondon17(p17t).agtottaversationinthefirstnucleotideofexon2wasidentifiedinaffectedindividualsofxzfamily.othergenesincriticalregionhavebeenexcludedfromacausativeroleinthepathogenesisofdgi-ii.theseresultshoweverdonotexcludemutatioinotherfamiliesoroccurredinnon–codingandregulationalregioofthesegenes,the800kbcriticalregionisaneasilymanipulatedfragment.therefore,thebaccontigsaingthecriticalintervalwerecreated
andcotructionofbacsequencingsubclonelibraryhasbeenfinished.theworkwillprovetobeacentralrecourceinthecreationofatracriptionmapandthesequenceoftheregionandwillaidintheultimatecloningofthedgi-iilocusinotherdgi-iioftheregionandwillaidintheultimatecloningifthedgi-iilocusinotherdgi-iifamilies,
keywords:hereditarygingivalfibromatosis,dentinogenesisimperfectatypeii,
positionalcloning,genomwidesearch,linkageanalysis