Downloadedfromgut.bmj.comonAugust6,2013-Publishedbygroup.bmj.com136Gut2002;50:136–138Postscript...............................................................................................IalsoquestionthediagnosisofWilson’ssensitivityofcaeruloplasmin,urinarycopperLETTERSdiseaseintwoofthepatientsinthisseries.excretion,andKayser-FleischerringsinthePatientNos20and22hadliverdiseasebutdiagnosisofWilson’sdisease.werenegativeforKayser-Fleischerrings,hadDrBrewer’ssecondpointrelatestoreportedDiagnosisofWilson’sdisease:anon-elevatedurinecopper,andnormallowlevelsofurinarycopperexcretioninsevenanexperienceoverthreecaeruloplasminlevels.Thediagnosiswassup-ofourpatients.InthesepatientsthevaluesdecadesposedlymadeinpatientNo20byelevatedwerereportedasµmol/24hourswhentheylivercopper.Non-Wilsonianchronicliverdis-shouldhavebeenconvertedtoµg/24hours.ThepaperbyGowetal(Gut2000;46:415–19)easecanalsoelevatehepaticcopper.12TheThetruelevelsforpatientNos6,7,8,11,12,discussedthediagnosisofWilson’sdiseaseindiagnosisinthispatientisuncertain,anddis-17,and20are312,117,437,1250,762,125,30patientspresentingtotwodifferentclinicalprovedifurinecopperistrulylow.PatientNoand100µg/24hours,respectively.facilitiesover28years(1971–1998).Becausea22alsohadelevatedlivercopperanda“posi-DrBreweralsoquestionedtheurinarycop-paperofthistypeislikelytobeviewedasantiveradiolabelledcopperplasmaclearanceperexcretionvaluesinpatientNos16and22.authoritativeguide,itisimportantthatthetest.”Again,hepaticcopperisnotproofoftheInbothofthesecasesthedatawererecheckedinformationbevalid.Forthatreason,Icalldiagnosis.Theabnormalradiocoppertestisandthereportedvalueswerefoundtobecor-attentiontothefollowingsignificanterrorsinsupportivebutWilson’sheterozygotes,com-rect.prisingabout1%ofthepopulation,areoftenthepaper.PJGowTheauthorsreporturinecoppervaluesof5,falselypositive.3Urinecopperof44µg,ifvalid,RASmallwood4,7,4,5,2,and2µgper24hoursinsevenwouldruleoutthediagnosis.patientsintheirtable1.ThesedatacannotInsummary,i