Izifo Chromosomal - zokugula, okuyinto incike ukuguquka kwezakhi zofuzo

Izinga yesimanje ukuthuthukiswa imithi iye yakufakazela ukuthi kungenzeka ukuba izifo ezithize noma okuvela isifo ngasiphi yobudala kungaba ngenxa yokuba izici zofuzo eziyingozi, noma ukunqotshwa abazali impahla lezinceku (chromosomes e kuguquka). Kuze kube manje it is neshaya ukuthi izifo chromosomal angase abe imbangela iziyaluyalu kwezitho zomzimba ahlukahlukene nezinye izimiso zomzimba, nokugasela ngamandla isifo kuxhomeke ezicini eziningi.

izifo Chromosomal - isigwebo 'sasezulwini' noma nomthelela imvelo?

Izimbangela lolu hlobo izifo lezi zinkinga isakhiwo wama-chromosomes ngabanye noma kokushintsha inombolo yabo. Ukuguqula izakhi zofuzo ezibanga womuntu chromosomal isifo kungenzeka igciwane amaseli abazali (kulesi simo izinguquko ngeke zikhonjwe wonke amaseli yenzalo omzimba) noma izigaba nasekuqaleni impela kokukhula kwayo sombungu. Kulokhu, ngezakhi zofuzo izinguquko cwaningo iyoba ukutholwa kuphela kwezinye kwamaseli - mosaicism kwenzeka. Kobukhulu ukwephulwa ngezindlela eziningi incike iphuzu lapho kwakukhona ukulahlekelwa wama-chromosomes kwabazali, indlela evelele lolu shintsho.

Isici-chromosomes kungenzeka ubulili-chromosomes futhi autosomes, futhi eqinisweni, kuzo zombili izimo zingenzeka ukulungiswa (ukuguquka kwezakhi zofuzo) kanye ushintsho lemali - ukwehla noma ukwanda kwenani abathwali kolwazi sitholwa njengefa. Iningi izifo chromosomal bazongena esitelekeni ukubonakaliswa emitholampilo, futhi kukhona umehluko phakathi izifo ezihlobene izilonda autosomes futhi ubulili chromosome ushintsho. Esimweni sokuqala isithombe emitholampilo ye isifo kubonakala ezinsukwini zokuqala zokuphila ngayo lapho usana, kuyilapho zokugula wama-chromosomes ocansini ungakwazi ngokucace wabonakaliswa kuphela inkathi yokuthomba wengane.

Izimbangela zezifo chromosomal

Ezimweni eziningi, imbangela chromosomal ukuguquka kwezakhi zofuzo kuba nomphumela ongemuhle eziyingozi yizici zemvelo ku-germ cells kanye nesidoda okunikelwe ezikuyo. izici Ezilimazayo kungenzeka ionizing emisebeni, izinga lokushisa eliphezulu futhi aphansi, zamakhemikhali, kuhlanganise imithi, ama-ejenti viral, kanye nezinguquko kule umzimba eziphilayo abazali.

Lapho karyotype kuyadingeka?

It is wafakazela ukuthi izinguquko kumaseli igciwane kungaba buthelela ngeminyaka, yingakho "yobudala" abazali ekuhleleni umndeni noma ngesikhathi okwashiwo ngesikhathi sokukhulelwa ngempela wathumela ukwelulekwa zofuzo. Kudinga izifundo chromosome (karyotype cwaningo abazali esizayo) izisu okuvele zifile esezithule, kanye ucwaningo oludingekayo ku kunjalo, uma udokotela usola noma yisiphi kwezinso chromosomal e ingane.

Izinga yesimanje ukuthuthukiswa imithi iye yakufakazela ukuthi kungenzeka omunye abathuthela kule ndawo nezifo efanayo chromosomal kubangelwe njengoba ushintsho inani lezakhi zofuzo kanye chromosome rearrangements e eqenjini elithile. Izifo ezihlala ngokuyinhloko lihlobene-Down syndrome, okungase kungenziwa ebizwa ngokuthi i ukwanda (trisomy 21 ngazimbili wama-chromosomes), kanye ukubanjwa "extra" 21 chromosome ngababili nezinye. Kulokhu, cwaningo khona izingane ekhaya nale zokugula zofuzo kusiza ukubikezela amathuba ukuba nomntwana ophile kahle.

izifo Chromosomal - kungenzeka ukwelapha?

Njalo udokotela ubani ukuze sibhekane nanoma ibuphi isifo chromosomal, kamunyu baphoqeleka ukuba bavume ukuthi ukuphathwa ezinkulu iziguli akunakwenzeka. Yingakho kokunqotshwa autosomes labetibambile ukwelashwa lingaze, yakhelwe kuphela ngezinga elincane, nxephezela iziyaluyalu asathuthuka. Kunoma ikuphi, iziguli atholakala ukukhubazeka amaningi, kuhlanganise retardation engqondo, zamehlo esimiso senhliziyo nemithambo yegazi, izinguquko ezimbi kakhulu umzimba.

Hlula Ama-chromosomes e ucansi, isibonelo, trisomy chromosome X, kungase ukuzibonakalisa kuphela amantombazane lapho efika eminyakeni yobudala zokuthomba. Lapho lesi sifo ezingavamile kombungu okwedlulele neziyaluyalu yokuzihlukanisa kwamangqamuzana ngokwemisebenzi yawo ngokobulili kwenzeka ngezinga elingakanani kungaba inzuzo izidakamizwa hormone. Kumele baqonde ukuthi lo ukwelashwa akunamthelela apharathasi lezinceku cell (ama-chromosomes e ngokwabo), kodwa kuyasiza ukuba abhekane ngokuphumelelayo nesitha sakhe ukuphambuka e isimo ngokomzimba nangokwengqondo iziguli.