医学遗传学20遗传咨询engv.ppt

Medical Genetics20 遗传咨询Genetic CounselingMedical GeneticsGenetic counseling is the process evaluatingfamilyhistoryandmedicalrecordsorderinggenetictestsevaluatingtheresultsofthisinvestigationhelpingparentsunderstandandreachdecisionsaboutwhattodonextMedical GeneticsGenetictestsaredonebyanalyzingsmallsamplesofbloodorbodytissues.Theydeterminewhetheryou,yourpartner,oryourbabycarrygenesforcertaininheriteddisorders.Medical Genetics1.GeneticCounselorsGeneticcounselorsarehealthprofessionalswithspecializedgraduatedegreesandexperienceintheareasofmedicalgeneticsandcounseling.Medical GeneticsMostenterthefieldfromavarietyofdisciplines,includingbiology,genetics,nursing,psychology,publichealthandsocialwork.Medical GeneticsGeneticcounselorsworkasmembersofahealthcareteam,providinginformationandsupporttofamilieswhohavememberswithbirthdefectsorgeneticdisordersandtofamilieswhomaybeatriskforavarietyofinheritedconditions.Medical GeneticsTheyidentifyfamiliesatrisk,investigatetheproblempresentinthefamily,interpretinformationaboutthedisorder,analyzeinheritancepatternsandrisksofrecurrence,andreviewavailableoptionswiththefamily.Medical GeneticsGeneticcounselorsalsoprovidesupportivecounselingtofamilies,serveaspatientadvocates,andreferindividualsandfamiliestocommunityorstatesupportservices.Medical GeneticsTheyserveaseducatorsandresourcepeopleforotherhealthcareprofessionalsandforthegeneralpublic.Medical GeneticsSomecounselorsalsoworkinadministrativecapacities.Manyengageinresearchactivitiesrelatedtothefieldofmedicalgeneticsandgeneticcounseling.Medical Genetics2.WhoShouldSeeOneMostcouplesplanningapregnancyorwhoareexpectingdontneedgeneticcounseling.Medical GeneticsAbout3%ofbabiesarebornwithbirthdefectseachyear,accordingtotheU.S.CentersforDiseaseControlandPrevention-andofthemalformationsthatdooccur,themostcommonarealsoamongthemosttreatable.Medical GeneticsCleftpalateandclubfoot,twoofthemorecommonbirthdefects,canbesurgicallyrepaired,ascanmanyheartmalformations.Medical GeneticsThebesttimetoseekgeneticcounselingisbeforebecomingpregnant,whenacounselorcanhelpassessyourriskfactors.Butevenafterhebecomepregnant,ameetingwithageneticcounselorcanstillbehelpful.Medical GeneticsForexample,severalbabieshavebeendiagnosedwithspinabifidabeforebirth.Recentresearchsuggeststhatdeliveringababywithspinabifidaviacesareansectioncanminimizedamagetothebabysspine-andperhapsreducethelikelihoodthatthechildwillneedawheelchair.Medical GeneticsYoushouldconsidergeneticcounselingifanyofthefollowingriskfactorsapplytoyou:(1)ifastandardprenatalscreeningtest(suchasthealphafetoproteintest)yieldsanabnormalresult(2)ifanamniocentesisyieldsanunexpectedresult(suchasachromosomaldefectintheunbornbaby)Medical Genetics(3)ifeitherparentoracloserelativehasaninheriteddiseaseorbirthdefect(4)ifeitherparentoracloserelativehasaninheriteddiseaseorbirthdefect(5)ifeitherparentalreadyhaschildrenwithbirthdefectsorgeneticdisordersMedical Genetics(6)ifthemother-to-behashadtwoormoremiscarriagesorbabiesthatdiedininfancy(7)ifthemother-to-bewillbe35orolderwhenthebabyisbornMedical GeneticsChancesofhavingachildwithDownsyndromeincreasewiththemothersage:a35-year-oldwomanhasaonein350chanceofconceivingachildwithDownsyndrome.Thischanceincreasestoonein110byage40andonein30byage45.Medical Genetics(8)ifparentsareconcernedaboutgeneticdefectsthatoccurfrequentlyintheirethnicorracialgroupMedical GeneticsForexample,couplesofAfricandescentaremostatriskforhavingachildwithsicklecellanemia;couplesofcentraloreasternEuropeanJewish(Ashekenazi),Cajun,orIrishdescentmaybecarriersofTay-Sachsdisease;andcouplesofItalian,Greek,orMiddleEasterndescentmaycarrythegeneforthalassemia,aredbloodcelldisorder.Medical Genetics3.WhattoExpectDuringaVisitBeforehemeetwithageneticcounselorinperson,youllbeaskedtogatherinformationabouthisfamilyhistory.Medical GeneticsThecounselorwillwanttoknowofanyrelativeswithgeneticdisorders,multiplemiscarriages,andearlyorunexplaineddeaths.Medical GeneticsThecounselorwillalsowanttolookoverhismedicalrecords,includinganyultrasounds,prenataltestresults,pastpregnancies,andmedicationshemayhavetakenbeforeorduringpregnancy.Medical GeneticsIfmoretestsarenecessary,thecounselorwillhelphimsetupthoseappointmentsandtrackthepaperwork.Whentheresultscomein,thecounselorwillcallhimwiththenews.Often,thecounselorwillencouragehimtocomeinforadiscussion.Medical GeneticsThecounselorwillstudyhisrecordsbeforemeetingwithhim,sohecanmakethebestuseofhistimetogether.Duringhissession,heorshewillgooveranygapsorpotentialproblemareasinhisfamilyormedicalhistory.Medical GeneticsThecounselorcanthenhelphimunderstandtheinheritancepatternsofanypotentialdisordersandhelpassesshischancesofhavingachildwiththosedisorders.Medical GeneticsHeorshewilldistinguishbetweenrisksthateverypregnancyfacesandrisksthathepersonallyfaces.Evenifhediscovershehasaparticularproblemgene,sciencecantalwayspredicttheseverityoftherelateddisease.Forinstance,achildwithcysticfibrosiscanhavedebilitatinglungproblemsor,lesscommonly,milderrespiratorysymptoms.Medical Genetics4.AfterCounselingHeandhisfamilywillhavetodecidewhattodonext.Geneticcounselorshelphimtounderstandhisoptionsandadjusttothedifficultiesanduncertaintieshefaces.Medical GeneticsIfhehaslearnedpriortoconceptionthatheand/orhispartnerareathighriskforhavingachildwithasevereorfataldefect,hisoptionsmightinclude:pre-implantationdiagnosisusingdonorspermordonoreggsadoptionMedical GeneticsIfhehasreceivedaprenataldiagnosisofasevereorfataldefect,hisoptionsmightinclude:preparinghimselfforthechallengesyoullfacewhenhehaveyourbabyfetalsurgerytorepairthedefectbeforebirthendingthepregnancyMedical GeneticsForsomefamilies,knowingthattheyllhaveaninfantwithasevereorfatalgeneticconditionseemstoomuchtobear.Otherfamiliesareabletoadapttothenews-andtothebirth-remarkablywell.Medical GeneticsGeneticcounselorscansharetheexperiencestheyvehadwithotherfamiliesinyoursituation.Buttheywillnot suggestaparticularcourseofaction.Medical GeneticsAgoodgeneticcounselorunderstandsthatwhatisrightforonefamilymaynotberightforanother.Medical GeneticsGeneticcounselorscan,however,referhetospecialistsforfurtherhelp.Forinstance,manybabieswithDownsyndromearebornwithheartdefects.Medical GeneticsThecounselormightencouragehimtomeetwithacardiologisttodiscussheartsurgery,andaneonatologisttodiscussthecareofapost-operativenewborn.Medical GeneticsGeneticcounselorscanalsoreferhetosocialworkers,supportgroups,ormentalhealthprofessionalstohelpheadjusttoandprepareforyourcomplexnewreality.