Isifo sikaHuntington yisimiso esiyinhloko esinezizukulwane ezizimele ezikhona lapho kuhlolwa khona izakhi zofuzo. Ukungafani kwezakhi zofuzo, ukwenyuka kokuphindaphinda kwe-CAG, kutholakala ku-chromosome 4.
Izifo ZikaHuntington Ziyini?
Isifo sikaHuntington yisimiso esiyinzalo esibekwe uphawu lokucindezeleka okukhulu kwenhlangano nokucindezeleka okuqhubekayo . Isifo sikaHuntington siqala cishe eminyakeni engama-40 ngokwesilinganiso, futhi, ngokuvamile, siqala phakathi neminyaka esemusha.
Labo abahluphekile ngesifo sikaHuntington banesikhathi sokuphila seminyaka eyi-10-20 emva kokuqala kwezimpawu.
Lesi simo sibangela ukukhubazeka okukhulu kanye nokwethembeka kwabathengisi njengoba kuqhubeka. Isifo sikaHuntington yisimo esingavamile, esithinta cishe umuntu oyedwa kwabayishumi kuya ku-10 kuya ku-10 000 emhlabeni wonke, ngokusakazeka okuncane phakathi kwabantu baseYurophu.
Ngeshwa, isifo sikaHuntington asitholakali okwamanje , kanti labo abatholakala benesifo abanakho ukwelashwa ngaphandle kokunakekelwa okusekelayo, okugxile ekuvimbeleni ukulimala nokugwema izinkinga, njengokungondleki kanye nezifo.
Isakhi esiphethwe yisifo sikaHuntington satholakala ngo-1993, kanti ukuhlolwa kwegazi kuyatholakala ukuthola ukuthi uphethe isakhi.
Umphumela wesifo nokuntula ukwelashwa yizizathu zokuthi kungani abantu ababazi isifo sikaHuntington emndenini bafuna ukuhlolwa kofuzo.
Ukubona ukugula ngokusebenzisa ukuhlolwa kofuzo kungasiza imindeni ukulungiselela izinkinga ezizayo, futhi ingasiza ekwenzeni izinqumo mayelana nokuhlelwa komndeni.
Ukuhlonishwa kwezifo zikaHuntington
Esinye sezizathu zokuhlolwa kwesifo se-Huntington esiwusizo kakhulu ukuthi isimo siyi- autosomal .
Lokhu kusho ukuthi uma umuntu ezuza isakhi esisodwa esingafaneleki sesifo sikaHuntington, khona-ke lowo muntu cishe uyakwazi ukuthuthukisa lesi sifo.
Isakhi sofuzo sikaHuntington sise-chromosome 4. Bonke abantu bazuza amakhophi amabili wegesi ngalinye; ngakho-ke bonke abantu banamakhophi amabili e-chromosome 4. Isizathu sokuthi lesi sifo sibonakala sinamandla ukuthi ukuphela kwesakhi sofuzo esisodwa sinokwanele ukudala isimo, ngisho noma umuntu enenye i-chromosome evamile. Uma unomzali onesifo, umzali wakho une-chromosome eyodwa ene-defect kanye ne-chromosome eyodwa ngaphandle kwephutha. Wena kanye nezingane zakubo ngamunye unethuba elingamaphesenti angu-50 lokuzuza lesi sifo kumzali wakho othintekile.
Izifo Zofuzo ZaseHuntington
I-Gene coding yenziwa ngokulandelana kwe-nucleic acids, okuyi-molecule e-DNA yethu efaka amakhomithini ukuthi imizimba yethu idinga umsebenzi ovamile. Ukwehluleka okukodwa kokukhokhwa kwesifo ku-Huntington's isifo senani lokuphindaphinda kwe-nucleic acid, i-cytosine, i-adenine ne-guanine, esifundeni se-exon yokuqala ye- HD geni. Lokhu kuchazwa njengokuphinda kwe-CAG.
Ngokuvamile, kufanele sibe nokuphindaphinda okungu-20 kwe-CAG kule ndawo ethile. Uma unokuphindaphinda kuka-26, awulindelekile ukuthuthukisa isifo sikaHuntington.
Uma uneminyaka ephakathi kuka-27 no-35 ukuphindwa kwe-CAG, cishe awukwazi ukuthuthukisa isimo, kodwa usengozini yokudlulisela lesi sifo enzalweni yakho. Uma uneminyaka ephakathi kuka-36 no-40 ukuphinda, ungase uhlakulele isimo sakho. Abantu abanokuphindaphinda kuka-40 kwe-CAG kulindeleke ukuthi bathuthukise lesi sifo.
Okunye okubhekwa nalesi siphambeko sofuzo ukuthi inani lokuphindaphinda livame ukwanda nesizukulwane ngasinye, izinto ezibizwa ngokuthi ukulindela. Ngakho-ke, isibonelo, uma unomzali onokuphindaphinda kuka-27 ku-CAG esifundeni obhekene nesifo sikaHuntington, ungaba nezingane zakubo ngokuphindaphinda kuka-31, futhi ingane yakho ingaba nengane ephindaphinda.
Ukubaluleka kokulindela ezakhiweni zesifo sikaHuntington ukuthi umuntu onokuphindaphindiwe kwe-CAG kulindeleke ukuba athuthukise izimpawu zesifo ngaphambi komuntu onokuphindaphindiwe okuncane.
I-Huntington's Gisease Test Genetic Testistics
Indlela yokuhlola isifo sikaHuntington ngukuhlolwa kwegazi. Ukunemba kokuhlolwa kuphezulu kakhulu. Ngokuvamile, ngenxa yokuthi isifo sikaHuntington sinesimo esibi kangaka, ukululekwa kunconywa ngaphambi nangemva kwemiphumela yokuhlolwa kofuzo.
Kunezinye zezindlela udokotela wakho angasebenzisa ukuze ahumushe kangcono imiphumela yakho yokuhlolwa. Isibonelo, uma wazi ukuthi unomzali onesifo sikaHuntington, udokotela wakho angase avivinye umzali wakho omunye futhi abone ukuthi inani le-CAG eliphindaphinda kuma-chromosomes akho ngalinye lifanisa nenani lokuphindaphinda kwe-chromosomes yabazali bakho . Ukuhlolwa kwezingane zakini kungasiza ukubeka imiphumela ebucayi.
Indlela i-HD Gene eyenza ngayo izifo zikaHuntington
Inkinga yezofuzo zesifo sikaHuntington, ukuphindaphinda kwe-CAG, kubangela ukungavamile ekukhiqizeni amaprotheni okuthiwa iprotheni yokuzingela. Akucaci kahle ukuthi yini le phrotheni eyenziwa kubantu abangenayo isifo sikaHuntington. Yini eyaziwayo, noma kunjalo, ukuthi kulesi sifo sikaHuntington, amaprotheni azingelayo anesikhathi eside kunokujwayelekile futhi ajwayele ukuhlukaniswa (ukuhlukana zibe izingxenye ezincane). Kukholelwa ukuthi lokhu kuhlukaniswa noma ukuhlukaniswa okubangelwayo kungase kube yingozi ukuze kusetshenziswe amangqamuzana ebuchosheni.
Isifunda esithile sobuchopho esithinta isifo sikaHuntington yisona se-basal ganglia, isifunda esijulile ebuchosheni esibizwa nangokuthi sinesibopho se-Parkinson's disease. Njengesifo sikaParkinson, isifo sikaHuntington sibhekene nezinkinga zokunyakaza, kodwa isifo sikaHuntington siphuthuma ngokushesha, siyabulala, futhi ukuwohloka komqondo yisifo esibonakalayo sesifo.
Izwi elivela
Isifo sikaHuntington yisimiso esibuhlungu esithinta abantu ekuqaleni kweminyaka yobudala kanye nokuholela ekufeni eminyakeni engama-20. Naphezu kokuqonda kwesayensi ngesifo, kukhona, ngeshwa, akukho ukwelashwa okunganciphisa ukuqhuma kwesifo futhi akukho ukwelashwa kwesifo.
Ukuhlolwa kwesifo sofuzo kwesifo sikaHuntington kuyintuthuko enkulu engasiza ekuthatheni izinqumo. Imiphumela yokuhlolwa kwezakhi zofuzo ingasiza ekuhleleni komndeni, nokulungiselela ukukhubazeka nokufa kusenesikhathi.
Uma wena noma umuntu owaziyo unesifo sikaHuntington noma utshelwe ukuthi lesi sifo sizovela eminyakeni ezayo, kuyasiza ukuxhuma namaqembu asekela njengendlela yokuqonda ukuthi ungabhekana kanjani nokuthi uncike kanjani kulabo abanokuhlangenwe nakho okufanayo.
Ukwengeza, nakuba kungekho ukwelashwa ngalesi sikhathi, ucwaningo luya phambili, futhi ungase ucabange iqhaza ocwaningweni locwaningo njengendlela yokufunda mayelana nezinketho zakho nokuthola izinketho zokwelapha zakamuva nezithuthukayo.
> Imithombo:
> Bates GP, Dorsey R, Gusella JF. Et al. Isifo seHuntington. Nat Rev Dis Primers. 2015 Apr 23; 1: 15005. doi: 10.1038 / nrdp.2015.5.
> Richard H. Myers. I-Huntington's Disease Genetics. I-NeuroRx. 2004 Apr; 1 (2): 255-262. i-doi: 10.1602 / neurorx.1.2.255 i-PMCID: PMC534940 i-PMID: 15717026