What is a genetic disorder? | Facts | yourgenome.org

A genetic disorder is an illness caused by changes in a person's DNA. · These mutations? can be due to an error in DNA replication? or due to ... In:Facts TargetingDisease Whatisageneticdisorder? Ageneticdisorderisadiseasethatiscausedbyachange,ormutation,inanindividual’sDNAsequence. Ageneticdisorderisanillnesscausedbychangesinaperson’sDNA. ThesemutationscanbeduetoanerrorinDNAreplicationorduetoenvironmentalfactors,suchascigarettesmokeandexposuretoradiation,whichcausechangesintheDNAsequence. Thehumangenomeisacomplexsetofinstructions,likearecipebook,directingourgrowthanddevelopment. However,unlikeaprintedbook,thehumangenomecanchange. Thesechangescanaffecttheindividualbases (A,C,GorT) ormuchlargerchunksofDNAorevenchromosomes. OurDNAprovidesthecodeformakingproteins,themoleculesthatperformmostofthefunctionsinourbody. However,whenasectionofourDNAischangedinsomeway,theproteinitcodesforisalsoaffectedandmaynolongerbeabletocarryoutitsnormalfunction. Dependingonwherethesemutationsoccur,theycanhavelittleornoeffect,ormayprofoundlyalterthebiologyofcellsinourbody,resultinginageneticdisorder. Geneticdisorderscanbegroupedintothreemaincategories:1. Singlegenedisorders: disorderscausedbydefectsinoneparticulargene,oftenwithsimpleandpredictableinheritancepatterns. Dominantdiseases: singlegenedisordersthatoccurwhenanindividualhasonealteredcopyoftherelevantgeneandonehealthycopy.Forexample,Huntington’sdisease. Recessivediseases: singlegenedisordersthatonlyoccurwhenanindividualhastwoalteredversionsoftherelevantgene.Forexample,cysticfibrosis. X-linkeddisorders: singlegenedisordersthatreflectthepresenceofanalteredgeneontheX chromosome.X-linkeddisordersaremorecommoninmalesbecausetheyonlyhaveoneXchromosome.Asaconsequencemalesonlyneedonecopyofthealteredgeneforsymptomstooccur.Forexample,musculardystrophy. 2. Chromosomedisorders: disordersresultingfromchangesinthenumberorstructureofthechromosomes. Forexample,Down’ssyndrome,whichresultsfromanextrachromosome21(trisomy21: threecopiesofchromosome21).Down’ssyndromeisachromosomedisorderresulting  fromanextrachromosome21.Imagecredit:Shutterstock3. Multifactorialdisorders(complexdiseases): disorderscausedbychanges inmultiplegenes,ofteninacomplexinteractionwithenvironmentalandlifestylefactorssuchasdietor cigarettesmoke. Forexample,cancer. Share Tweet Pin Thispagewaslastupdatedon2021-07-21 Í RelatedContent:  Whataresinglegenedisorders? Facts SinglegenedisordersarecausedbyDNAchangesinoneparticulargene,andoftenhavepredictableinheritancepatterns. Whattypesofmutationarethere? Facts TherearelotsofdifferentmutationsthatcanoccurinourDNA.  Whatisamutation? Facts AmutationisachangethatoccursinourDNAsequence,eitherduetomistakeswhentheDNAiscopiedorastheresultofenvironmentalfactorssuchasUVlightandcigarettesmoke.  Whatisachromosome? Facts ChromosomesarebundlesoftightlycoiledDNA locatedwithinthenucleusofalmosteverycellinourbody.Humanshave23pairsofchromosomes. Whatisachromosomedisorder? Facts Achromosomedisorderresultsfromachangeinthenumberorstructureofchromosomes.  WhatisDown'ssyndrome? Facts Down’ssyndromeisageneticdisordercausedbythepresenceofallorpartofanextracopyofchromosome21. Whatiscysticfibrosis? Facts Cysticfibrosisisarelativelycommongeneticconditioninwhichthelungsanddigestivesystembecomecloggedwiththick,stickymucus.  Whatismusculardystrophy? Facts DuchenneandBeckermusculardystrophyaretwoinheritedmuscle-wastingdiseasescausedbymutationsinthesamegeneontheXchromosome.  WhatisHuntington'sdisease? Facts Huntington’sdiseaseisaprogressiveneurodegenerativedisorderthatusuallydevelopsinmiddletolateadultlife. Iscancerageneticdisease? Facts Canceristhemostcommonhumangeneticdisease.Thetransitionfromanormalcelltoamalignantcancerisdrivenbychangestoacell’sDNA,alsoknownasmutations. Whatisacomplexdisease? Facts Manycommondiseasesareinfluencedbyacombinationofmultiplegenesandenvironmentalfactors.Thesediseasesarereferredtoascomplexdiseases. Howhelpfulwasthispage? 👎👍 Send What'sthemainreasonforyourrating? Send Whichofthesebestdescribesyouroccupation? Student Scientist/Researcher Teacher Other Send howoldarestudents/howoldareyou? <11 11-16 16-18 18-25 >25 Send Whatisthefirstpartofyourschool'spostcode? Send Howhasthesiteinfluencedyou(orothers)? Send Thankyou,wevalueyourfeedback! Ifyouhaveanyothercommentsorsuggestions,[email protected] Feedback Canyouspare5-8minutestotelluswhatyouthinkofthiswebsite?Opensurvey   Weusecookiestoimprovethissite.IUnderstand