Isifo sikaHuntington sisigxina esizimeleyo esinezizukulwana eziza kuba nezovavanyo zofuzo. Imfuza engafaniyo, ukwanda kwe-CAG ukuphinda, kufumaneka kwi-chromosome 4.
Ziziphi izifo zeHuntington?
Isifo sikaHuntington sisimo esiyifa esibekwa yintlungu yokunyakaza nokunyuka kwengqondo okuqhubekayo . Isifo sikaHuntington siqala malunga no-40 ubudala kumyinge, kwaye, ngokuqhelekileyo, siqala ngethuba leminyaka elivisayo.
Abo baxhatshazwa ngesifo sikaHuntington banomdla wobomi malunga neminyaka eyi-10-20 emva kokuqala kweempawu.
Le meko ibangela ukukhubazeka okukhulu kunye nokuxhomekeka kwenyameko kubanakekeli njengoko kuqhubeka. Isifo sikaHuntington sisimo esingavamile, esichaphazela malunga ne-1 kubantu abayi-10 000 ukuya kuma-10,000 ukuya ku-20 000 kwihlabathi lonke, ngokuxhaphake kakhulu kubantu baseYurophu.
Ngelishwa, isifo sikaHuntington asinakuphulukiswa , kwaye abo bafumaniswe ngeso sifo abanakho ukhetho lwonyango ngaphandle kokunyamekela, okujoliswe ekukhuselweni kokulimala nokukhusela iingxaki, njengokungondleki kunye nezifo.
Umzimba ojongene nesifo sikaHuntington ufumene ngo-1993, kwaye uvavanyo lwegazi lufumaneka ukuba luchonge ukuba ngaba uphethe i-gene.
Isiphumo sesi sifo kunye nokungabi nonyango ziphakathi kwezizathu zokuba abantu ababazi isifo sikaHuntington kwintsapho bafuna ukuhlolwa kofuzo.
Ukuchonga isigulo ngokuhlolwa kofuzo kunokunceda iintsapho zilungiselele ubunzima obuzayo, kwaye lunokunceda ekwenzeni izigqibo malunga nokucwangcisa intsapho.
Ukunyaniseka kwezifo zikaHuntington
Esinye sezizathu zokuba uvavanyo lofuzo lwesifo sikaHuntington luncedo gqitha kukuba le meko ibona i- autosomal .
Oku kuthetha ukuba ukuba umntu uzuza ilifa elilodwa eliphene kwisifo sikaHuntington, ngoko lowo mntu unako ukuhlakulela isifo.
Umgubo weHuntington ufumaneka kwi-chromosome 4. Bonke abantu bazuza iikopi ezimbini zeefom nganye; ngoko bonke abantu baneikopi ezimbini ze-chromosome 4. Isizathu sokuba esi sifo sibonakala sisigxina kukuba i-gene esisodwa esisweleko sinokwanela ukudala imeko, nangona umntu enesinye i-chromosome evamile. Ukuba unomzali onesi sifo, umzali wakho unechromosome enye enephene kunye nekromosome enye ngaphandle kwesiphene. Wena kunye nomntakwabo ngamnye unokufumana ithuba lokufumana esi sifo kwisifo sakho kumzali wakho ochaphazelekayo.
Izifo ze-Genetics ze-Huntington's
I-gene coding yenziwe ngokulandelelana kwamacidi e-nucleic, ayenama-molecule kwi-DNA yethu ekhokelela kwiiprotheni ezinokuthi umzimba wethu udinga umsebenzi oqhelekileyo. Isalathiso esithile senkcazo kwisifo sikaHuntington sinyuke kwinani lokuphindaphinda kwee-nucleic acid, i-cytosine, i-adenine kunye ne-guanine, kwingingqi ye-exon yokuqala ye- HD gene. Oku kuchazwa njengokuphinda kweCAG.
Ngokuqhelekileyo, kufuneka sibe nokuphinda kwama-20 eCAG kule ndawo ethile. Ukuba unaphinda ngaphaya kwe-26, awukulindelekile ukuba uhlakulele isifo sikaHuntington.
Ukuba unokuphindaphinda phakathi kwe-27 no-35 kwe-CAG, akunakwenzeka ukuba uhlakulele imeko, kodwa usengozini yokudlulisa esi sifo kwintwana yakho. Ukuba uneminyaka ephakathi kwama-36 no-40 ubuyaphinda, unokuhlakulela imeko ngokwakho. Abantu abanokuphindaphinda kwama-CAG angama-40 kulindeleke ukuba bahlakulele isifo.
Olunye uphando malunga nale mpahla yemfuza kukuba inani lokuphindaphinda lisoloko landa kunye nesizukulwana ngasinye, into eyaziwayo njengekulindeleke. Ngoko, umzekelo, ukuba unomzali onokuphindaphinda kwama-27 kwi-CAG kwingingqi ejongene nesifo sikaHuntington, unokuba ne-siblings ngokuphindaphindiweyo kwe-31, kwaye umntakwenu unokuba nomntwana ophindaphindiweyo.
Ukubaluleka kokulindela kwi-genetics yesifo sikaHuntington kukuba umntu onokuphindaphinda ngaphezulu kwe-CAG kulindeleke ukuba akhulise iimpawu zesifo ngaphambi komntu onokuphindaphinda.
I-Huntington's Disease Genetic Test Logistics
Indlela yokuvavanya isifo sikaHuntington kukuhlolwa kwegazi. Ukuchaneka kovavanyo luphezulu kakhulu. Ngokuqhelekileyo, ngenxa yokuba isifo sikaHuntington sisimo esibi kakhulu, ukucetyiswa kukucetyiswa ngaphambi nangemva kweemvavanyo zakho zovavanyo.
Kukho izicwangciso ogqirha wakho angasebenzisa ukuphucula kangcono iziphumo zakho zokuvavanya. Umzekelo, ukuba uyazi ukuba unomzali wesifo sikaHuntington, ugqirha wakho unokuvavanya umzali wakho kunye nokubona indlela inani leCAG eliphindaphinda ngayo ngalinye le-chromosomes yakho lifanisa nenani lokuphindaphinda ngalinye le-chromosomes yabazali bakho. . Ukuvavanywa kwabantwana babantwana banokukunceda ukubeka iziphumo ngombono.
Indlela i-HD yeGene ibangela ngayo izifo zikaHuntington
Ingxaki yemfuyo yesifo sikaHuntington, ukuphindaphinda kwe-CAG, ibangela ukungavumelekanga kwiprotheyini ebizwa ngokuba yiprotheni yokuzingela. Akucaci kakuhle ukuba yintoni le protein eyenziwa ngabantu abangenayo isifo sikaHuntington. Yintoni eyaziwayo, nokuba kunjalo, kwisifo sikaHuntington, iprotheni yokuzingela ide kunexesha eliqhelekileyo kwaye iyanqwenela ukuhlukana (ukuphuka kumacandelo amancinci). Kukholelwa ukuba le nxalenye okanye ukutyunjwa okubangelwa yinto enobungozi kumasipha eengqondo.
Ummandla othile wengqondo ochaphazelekayo ngesifo sikaHuntington yi-basal ganglia, ummandla ophantsi kwengqondo eyaziwa ngokuba yinto ejongene nesifo sika-Parkinson. Njengesifo sika-Parkinson, isifo sikaHuntington sibonakala ngeengxaki zenkqubela, kodwa isifo sikaHuntington siphumelela ngokukhawuleza, sisifo esibulalayo, kwaye ukugula komzimba kuyona nto ibonakalayo yesifo.
ILizwi
Isifo sikaHuntington sisimo esibuhlungu esichaphazela abantu beminyaka yobudala obudala kunye nokukhokelela ekufeni kwiminyaka engama-20. Nangona ukuqonda kwezesayensi zesifo, kukho, ngelishwa, akukho unyango olunganciphisa ukukhula kwesifo kwaye akukho unyango lwesifo.
Uvavanyo lwe-Genetic lwesifo sikaHuntington luqhubekela phambili olukhulu olunokukunceda ekuthatheni izigqibo. Iziphumo zokuvavanya i-genetic zingancedisa ngocwangciso lwezesapho, kunye nokulungiselela ukukhubazeka nokufa kwangaphambili.
Ukuba wena okanye umntu owaziyo unesi sifo sikaHuntington okanye uye watshelwa ukuba lesi sifo siya kuvela kwiminyaka ezayo, kunceda ukudibanisa namaqela enkxaso njengendlela yokuqonda ngayo indlela yokujamelana ngayo kunye nokuxhomekeka kwabo banamava afanayo.
Ukongezelela, ngelixa kungekho nonyango okwangoku, uphando luya phambili, kwaye unokucinga ukuba uthatha inxaxheba kwisifundo sophando njengendlela yokufunda malunga nokukhetha kwakho kwaye ufumane ukufikelela kwiinketho zonyango eziphuhliswayo kunye neendlela ezikhulayo.
> Imithombo:
> Bates GP, Dorsey R, Gusella JF. Okqhubekayo. Isifo seHuntington. Nat Rev Dis Primers. 2015 Apr 23; 1: 15005. i-doi: 10.1038 / nrdp.2015.5.
> URichard H. Myers. Izifo ze-Genetics zeHuntington. NeuroRx. 2004 ngoMatshi; 1 (2): 255-262. i-doi: 10.1602 / neurorx.1.2.255 I-PMCID: PMC534940 i-PMID: 15717026