Translocations Robertsonian: incazelo, izici kanye nezici

Yonke ivolumu nesidoda okunikelwe ifakwe konke ngazimbili 46 wama-chromosomes. A-chromosome is kusukela biology ezaziwayo, atholakala kuyi-nucleus yengqamuzana. Umuntu enempilo has a karyotype ka 23 ngazimbili wama-chromosomes diploid. Lokho 46 XX - chromosome setha abesifazane 46 XY - isethi besilisa lezakhi zofuzo. Uma wephula noma yiziphi-chromosome, okuyisisekelo "umphathi kaNkulunkulu" ikhodi yofuzo, izinhlobo ezahlukene ukwephulwa zenzeka.

Ukuguqula izakhi zofuzo Akubona abantu. izinguquko ezincane nesidoda okunikelwe neqhaza ukwehluka izindlela imvelo eyayibonakala ngazo. Esikhathini okuthiwa olinganiselayo chromosomal translocation ushintsho kwenzeka ngaphandle ukulahlekelwa ulwazi futhi ngaphandle ukuphindaphindeka okungadingekile. Ngokuvamile lokhu kwenzeka ngesikhathi meiosis (chromosome division), ngaphezu, ngezinye izikhathi ingxenye chromosome ayimpinda (ukuphindwa kwenzeka), bese imiphumela ezingalindelekile. Kodwa sizocabangela translocations Robertsonian kuphela, izici zabo nemiphumela.

translocation Robertsonian - kuyini? izinkinga zofuzo zesintu

Ngenxa ukudabuka we-chromosome eduze centromere zikhona izinguquko ezihlelekile e izakhi zofuzo lomuntu nokukwazi. Igebe kungaba olulodwa, kodwa kuyenzeka futhi futhi. Omunye ingalo chromosome ngemva kwekhefu (ngokuvamile ingalo iDemo) kulahleka. Kodwa uhlangabezana ezimweni lapho ikhefu kwenzeka ngasikhathi sinye 2 Ama-chromosomes e, izingalo zazo ushintshanisiwe. Ngezinye izikhathi, kufanele atitfobe translocation kuphela uma izingxenye ehlombe. Kodwa ezinjalo kusetshenziswa kakhulu izikhali iDemo wama-chromosomes acrocentric e uhlobo (lapho centromere uhlukanisa chromosome kwi izingalo eside futhi esifushane) abaziphathi nanini izibhamu ukwaziswa okubalulekile. Ngaphandle nokulahlekelwa izici eziningana ezinjengolwazi akubalulekile kangako ngoba impahla lezinceku ikopishelwe omunye Ama-chromosomes e acrocentric.

Kodwa lapho wahlukanisa ingalo iDemo tho nge izingalo esifushane omunye isakhi sofuzo, nobude esisele futhi soldered komunye nomunye, a translocation enjalo ayisekho olinganiselayo. "Rearrangement" ezinjalo eziyisisekelo zofuzo - lena translocation Robertsonian.

Ngacwaninga futhi echazwe kulolu hlobo translocation W. Robertson ngo-1916. Futhi igama lakhe lathiwa futhi anomaly. translocation Robertsonian kungaholela ukuthuthukiswa zomdlavuza, kodwa kungase kube nomthelela ukubukeka futhi impilo yenethiwekhi. Nokho, ingane ezimweni eziningi, uma omunye umzali translocation, ozalwa abanokukhubazeka.

kuguquka kanjani abavamile?

Ngenxa intuthuko kwezobuchwepheshe kanye nokuthuthukiswa zofuzo njengendlela isayensi, namuhla kungenzeka ukwazi kusengaphambili uma kukhona kwezinso ku karyotype wengane ongakazalwa. Manje kungenzeka ukuba afeze izibalo: kangaki kukhona anomaly zofuzo? Ngokusho idatha zamanje, translocations Robertsonian zenzeka oyedwa nosana ayizinkulungwane. Iningi ngokuvamile kutholakala ukuthi uphethwe yini translocation ne-chromosome 21.

Small chromosomal translocation nhlobo usongo lwezikhali yayo. Kodwa uma sithinta ezibalulekile ikhodi, ingane ingase izalwe efile noma bafe ezinyangeni ezimbalwa, ezifana, isibonelo, leli cala lo Patau syndrome. Kodwa Patau syndrome kwenzeka kakhulu kuyaqabukela. Endaweni ethile 1 e 15,000 ukubeletha.

Izici ezibangela kwavela translocation e-chromosomes

Emvelweni, zikhona izinto ngokuguqula izakhi, nokuguqulwa, okungukuthi, ama. Kodwa imvelo kwenza izinguquko ayo ekuthuthukiseni ufuzo. Kunezici eziningana ezingase neqhaza izinguquko njalo mutational. Lezi zici abizwa ngokuthi mutagenic. Aziwe lezi zinto ezilandelayo:

• nomthelela elisekela nitrogen;
• alien biopolymers DNA;
• KOMAMA nophuzo oludakayo lapho ukhulelwe;
• umthelela amagciwane ngesikhathi sokukhulelwa.

I translocation ezivamile kwenzeka ngenxa yemiphumela eyingozi emisebeni emzimbeni. Kuthinta emisebeni ultraviolet, ama-proton ne-X ray, futhi-gamma rays.

Yikuphi iyashintsha chromosome?

Ibhekane translocation chromosome 13, 14, 15 no-21: ethandwa kakhulu futhi iyingozi translocation - a translocation Robertsonian phakathi Ama-chromosomes e-14 kuya ku-21.

Uma ngenxa meiosis amafomu chromosome eyengeziwe (trisomy) fetus nge translocation ezinjalo, ingane izalwe ine-Down syndrome. Icala efanayo kungenzeka uma Robertsonian translocation livelile phakathi Ama-chromosomes e-15 no-21.

Translocation chromosome band D

Robertsonian translocation chromosome Iqembu D kuthinta Ama-chromosomes e acrocentric kuphela. Ama-chromosomes e-13 14 zinengxenye translocations e-74% amacala, futhi babizwa translocations ongenakulinganisela, ngokuvamile imiphumela eyingozi empilweni akuzona.

Nokho, kukhona esinye isimo esingase ezihambisana anomalies enjalo. translocation Robertsonian 13, 14 ezingabantu kungaholela wenzalo kahle esiphathiswa owesilisa (45 xy chromosome isethi). Ngenxa yokuthi, ngenxa ekulahlekelweni zombili izingalo kafushane, kunokuba 2 ngazimbili wama-chromosomes ngokuvamile nguye has ezimbili ezinde, gametes umuntu onjalo abakwazi ukunikeza inzalo iphila kuphela.

esifanayo translocation Robertsonian 13, 14 abantu besifazane kunciphisa ikhono layo ukuba nomntwana. Nyanga zonke kukhona abesifazane abanjalo, kodwa kunezikhathi lapho uzale izingane enempilo. Kodwa izibalo isazobonisa ukuthi akuvamile. Empeleni, izingane zabo azisizi.

Imiphumela translocations

Siye sathola ukuthi ezinye izinguquko ezihlelekile ziyezwakala ngempela futhi musa ukusongela. Robertsonian translocation iyunithi kunqunywa kuphela ukuhlaziywa. Kodwa kabusha translocation e isethi isizukulwane esilandelayo wama-chromosomes esiyingozi kakade.

translocation Robertsonian 15 futhi 21 ngokuhlanganyela nezinye izinguquko ezihlelekile kungenzeka ngisho eyinhlekelele. Zonke imiphumela izinguquko ezithile ezihlelekile karyotype kuchazwe kabanzi. Khumbula ukuthi karyotype - ke sizalwa nawo isethi ngabanye wama-chromosomes e-nucleus.

Trisomy futhi translocation

Ngaphezu kwalokho translocations Ufuzo isehlane angahlangani ezifana chromosome trisomy. Trisomy kusho ukuthi karyotype fetus umise omunye wama-chromosomes triploid esikhundleni amakhophi 2 ngezinye izikhathi kwenzeka trisomy KaMose. Lokho triploid iqoqo waphawula hhayi zonke emangqamuzaneni omzimba.

Trisomy kuhlangene translocation Robertsonian kuholela nemiphumela emibi kakhulu: ezifana Patau syndrome, Edwards futhi kwande-Down syndrome. Kwezinye izimo, isethi anomalies kuholela kwesisu kusaqalwa.

Down Syndrome. ukubonakaliswa

Kufanele kuqashelwe ukuthi translocation ezihilela Ama-chromosomes e-21 kanye no-22 kukhona umuntu omdala ophumelelayo. anomalies ezinjalo akubulali, akuzona isigamu-ebulalayo, kodwa umane kuholele abakhubazekile entuthuko. Ngakho, trisomy 21 lihambisana translocation Robertsonian ku karyotype e ukuhlaziywa karyotype fetus - 'yesibonakaliso' eliqinisekile-Down syndrome, isifo esidluliselwa ngofuzo.

Down Syndrome libhekene kokubili abakhubazekile ngokomzimba nangokwengqondo. Ukubikezela zokuphila balaba bantu sisihle. Naphezu isifo senhliziyo kanye izinguquko bokuphila kuleli skeleton, nomzimba wabo usebenza kahle.

Izici sici syndrome:

• ubuso flat;
• ulimi lakhulisiwe;
• eziningi isikhumba entanyeni, uya phinda;
• clinodactyly (ugobile iminwe);
• epicanthus;
• isifo senhliziyo kungenzeka e-40% amacala.

Abantu nale syndrome kancane uqale ukuya, ukusho amagama. Futhi ukufunda kube nzima kunamanye izingane beminyaka yobudala efanayo.

Nokho ziyakwazi umsebenzi wokudala emphakathini futhi ezinye ukwesekwa futhi kuyasebenza efanele nalezi izingane basuke kahle ayeba esikhathini esizayo.

Patau syndrome

Lesi sifo lingaphansi ezivamile kuka-Down syndrome, kodwa izici ezihlukahlukene abe ingane enjalo kakhulu. Cishe u-80% izingane nale Ihlahlubo ufe kungakapheli unyaka ongu-1 ubudala.

Ngo-1960 yena wafunda ngale anomaly futhi bathola izimbangela kwezakhi ukwehluleka Klaus Patau, nakuba kuye 1657 echazwe lesi sifo T. Bartolini. Ubungozi yalezi zinkinga luyanda nabesifazane ababemkhalela ubelethe ingane emva kweminyaka 31.

Lezi zingane ziyizisulu ukukhubazeka enciphile emzimbeni kuhlangene ukuthuthukiswa okukhulu lengqondo. Isici yalesi sifo:

• microcephaly;
• izandla normal, ngokuvamile kwakheka izinzwane ezengeziwe;
• ongaphakeme isethi izindlebe ukuma okungajwayelekile;
• lip emfantwini;
• entanyeni iDemo;
• amehlo eliwumngcingo;
• ngokucacile "lushone" ibhuloho;
• zamehlo izinso nenhliziyo;
• emfantwini lip noma ulwanga;
• Ukukhulelwa Kukhona Umthambo enkabeni eyodwa kuphela.

Idlanzana lokusinda izinsana usizo lwezokwelapha. Futhi luyakwazi ukuphila isikhathi eside. Kodwa anomalies azalwa naso ezisasithinta nesimo sokuphila nangamafuphi yayo.

Edwards syndrome

Trisomy 18 chromosome translocation ngemuva kuholela Edwards Syndrome. Lesi sifo incane eyaziwayo. Nale uphethwe ingane ngokulambisa ziphile zize izinyanga eziyisithupha. Ukukhetha umthetho wemvelo ayikuvumeli sikhule kakhulu abakhubazekile amaningi.

Ngokuvamile, inani obungefani e sifo Edwards - mayelana 150 abakhona izitsha kombungu igazi, inhliziyo, izitho zangaphakathi. Njalo ekhona lezi zingane hypoplasia we cerebellum. Kukhona okungahambi ngendlela akheke ngayo iminwe. Isikhathi esining impela a anomaly ehlukile enjalo ivela njengendlela deformity unyawo.

Iluphi uvivinyo ukucacisa kahle kwezinso ku utero?

Ukuze karyotype ukuhlaziya fetus ezidingekayo ukuze bathole izinto - amaseli fetus.

cwaningo eziningana. Likhanyise ke kwenzeka kanjani.

1. chorionic villus izibonelo zalokho. Uhlaziyo uma sebehlanganisa amasonto angu-10. Lezi villi - yiwona ngqo kuyizinhlayiyana placenta. Lokhu kuyizinhlayiyana of izinto eziphilayo azithathe uzokutshela konke mayelana nekusasa izithelo.

2. Amniocentesis. Nge inaliti sithathwa amaseli fetus ambalwa, futhi-amniotic fluid. Ezithathwe ikakhulukazi ngesonto 16 yokukhulelwa, futhi ngemva kwamasonto ambalwa, lo mbhangqwana ungakwenza uthole ulwazi lemininingwane mayelana nokuthi inhlalakahle yengane.

Kuleli ukuhlaziywa ithunyelwa nabonina ingozi ekuthumeleni ingane abanokukhubazeka anda. Ngokuvamile ukuhlaziywa zofuzo iqondiswe labo ngazimbili lapho:

1) kwakufanele izisu kwenja;

2) umbhangqwana uye wahluleka okukhulelwa ingane;

3) e umndeni uya ehlobene eduze ukuxhumana nemvelo.

Laba bantu abasha bangase babe translocations Robertsonian kwezinye chromosome. Futhi ngakho kufanele kuthuthukiswe ukwenza ukuhlaziywa on karyotype ukwazi ukuthi amathuba okuba ukuba baphathe futhi ubelethe ingane ephile saka.