Ukwehlukana kwezidakamizwa kungabangela ukukhubazeka noma ukuphuma kwesisu
Ukungajwayelekile kwe-chromosomal kwenzeka lapho ingane ikhona inombolo engalungile ye-chromosomes noma i-chromosomes ehlelekile. Lezi zimo ezingavamile zingase zihumushe ekuthuthukiseni ukukhubazeka kokuzalwa, izinkinga ezifana ne-Down syndrome, noma ukukhulelwa komzimba.
Ukuqonda iziGenesis nama-Chromosomes
Umzimba wakho wakhiwe ngamaseli. Phakathi kweseli ngayinye yi-nucleus, futhi ngaphakathi kwe-nucleus kukhona ama-chromosomes.
I-Chromosomes ibalulekile ngoba iqukethe izakhi zofuzo ezinquma izici zakho zomzimba, uhlobo lwegazi lakho, nokuthi ngabe uzoba kanjani nezifo ezithile.
Iseli ngayinye emzimbeni iqukethe ama-chromosomes angu-23 - angu-46 kuwo wonke umuntu - ngalinye eliqukethe izakhi zofuzo ezingaba ngu-20 000 kuya ku-25 000. Ingxenye yama-chromosomes akho avela eqanda likamama wakho nengxenye ivela kumuntu kababa wakho.
Ezimbili ezingu-23 zama-chromosomes, ama-pair amabili okuqala abizwa ngokuthi ama-autosomes. Ama-chromosomes amabili wokugcina, okwamanje, abizwa ngokuthi ama-allosomes. Eyaziwa nangokuthi i-chromosomes yobulili, i-allosomes inqume ubulili bomuntu siqu nezici zobulili. Insikazi inama-chromosomes amabili amabili (XX) kanti owesilisa une-X ne-Y chromosome (XY).
Ukungahleleki kwe-Chromosomal nokuHlangana
Ukungajwayelekile kwe-Chromosomal kungenye yezizathu eziyinhloko zokukhulelwa kwesisu esikhathini sokuqala kwe-trimester. Ekuqaleni kokukhulelwa kwesisu, amaphutha e-chromosomal angavimbela ingane ukuba ingathuthuki ngendlela evamile.
Uma lokhu kwenzeka, isimiso somzimba sokuzivikela sasizophendula ngokuzenzakalela ukuqeda ukukhulelwa.
Ucwaningo lubonisa ukuthi okungavamile kwe-chromosomal kulandela amaphesenti angama-60 kuya kwangu-70 wezinsizakalo zokuqala zangesikhathi. Ezimweni eziningi, leli phutha liyi-anomaly engahleliwe, kanti lona wesifazane uzoqhubeka nokukhulelwa okulandelayo.
Inombolo ephawulekayo yokuhlukumeza okubangelwa ukuhlukunyezwa kubangelwa uhlobo lwe-disorder lapho kunamakhophi amathathu we-chromosome kunokubili. Lokhu kubiza i-trisomy. Izibonelo ze- trisomy 16 ne- trisomy 9 , ezihlanganisa ndawonye amaphesenti angaba ngu-13 azo zonke iziphambeko zokuqala ezintathu.
Kwezinye izimo, ukungavamile kwe-chromosomal kungaholela esimweni esingavamile esibizwa ngokuthi ukukhulelwa kwe-molar . Ngesikhathi sokukhulelwa kwe-molar, izicubu ezazihloselwe ukwakha emfantwini kunalokho zibe ukukhula okungavamile esibelethweni. Kunezinhlobo ezimbili zokukhulelwa kwe-molar:
- Ukukhulelwa okuphelele kwe-molar kubangelwa uma iqanda lingenalo ulwazi lofuzo. Iqala i-placenta ebukeka njengeqoqo lamagilebhisi ngaphandle kwesisu esilandelayo.
- Ukukhulelwa okuncane okukwenzekayo kwenzeka uma iqanda likhulelwa izimila ezimbili. Kubangelwa ukuthuthukiswa kombungu okhubazekile kakhulu futhi ngokuvamile awuhlali.
I-Down Syndrome nezinye izinto ezingezansi ze-Chromosomal
Enye yezinkinga ezidumile kakhulu ze-chromosomal yi-Down syndrome ebangelwa ikhophi eyengeziwe ye-chromosome ebizwa ngokuthi i-chromosome 21. Kungenxa yalesi sizathu ukuthi siphinde sibhekane nesifo njengesi-trisomy 21.
Ezinye zezici ezivamile ze-Down Syndrome ziyizilinganiso ezincane, ukugxila phezulu kwamehlo, ithoni ephansi ye-muscle, nokujula okujulile phakathi kwensika yesandla.
Omunye wabantwana abangu-691 base-US uzalwa nge-Down syndrome.
Isizathu salesi sifo asikho ngokuphelele, kodwa ososayensi baye baqaphela, phakathi kwezinye izinto, ukuxhumana okuvamile phakathi kweminyaka yobudala bomama kanye nokuthuthukiswa kwesifo. Ingozi iboniswe ukwandisa ngokucacile njengowesifazane wesifazane, kusukela ku-1 500 eneminyaka engu-20 kuya kweyodwa ku-50 eneminyaka engu-43 ubudala.
Ngaphezu kwe-trisomy 21, kunezinye izifo ezihlobene nokukhona kwe-chromosome eyengeziwe. Omkhulu phakathi kwabo:
- I-Trisomy 18, eyaziwa nangokuthi i-Edwards syndrome, iyenzeka kwenye yezingu-2 500 zokukhulelwa kanye neyodwa kwabazali abangu-6,000 base-US Le disorder ibonakala ngesisindo sokuzalwa esincane, ikhanda elincinci elingavamile, nezinye izinkinga ezingasongela impilo. I-Edwards syndrome ayinayo ukwelashwa futhi ivame ukubulala ngaphambi kokuzalwa noma kungakapheli ngonyaka wokuqala wokuphila.
- I-Trisomy 13, eyaziwa nangokuthi i-Patau syndrome, ingabangela ukukhubazeka okukhulu kwengqondo kanye nokukhubazeka kwenhliziyo, amehlo angathuthuki, iminwe eyengeziwe noma izinzwane, umlomo ocacile, nobuchopho noma intambo yomgogodla okungavamile. I-Patau syndrome iyenzeka kwenye yazo zonke izinhlobo zokuzalwa ezingu-16,000, kanti izinsana zivame ukufa ezinsukwini zokuqala noma emasontweni okuphila.
- I-Klinefelter syndrome, eyaziwa nangokuthi i-XXY syndrome, ingumphumela we-X chromosome eyengeziwe emadodeni. Ihlotshaniswa namazinga aphezulu obuhlanya kanye nokukhubazeka ngokocansi. Ngokuvamile uyaqaphela kuze kube yilapho sekukhulelwa uma ibonakala ngesimiso esincane, isiqu eside, izinwele ezincane zomzimba, kanye namazinyo omzimba omncane.
Ngokuphambene nalokho, ukungezwa kwe-Y eyengeziwe kumadoda (XYY) noma i-X eyengeziwe kuma-female (XXX) ayibangeli noma yiziphi izici ezithile zomzimba noma ukukhathazeka kwezempilo. Nakuba ezinye zalezi zingane zingaba nezinkinga zokufunda, zivame ukukhula ngendlela evamile futhi ziyakwazi ukukhulelwa izingane.
Ukuhlolwa kwe-Chromosomal
Ngasekupheleni kokuqala kwakho kokuqala, ungakhetha ukuthi ube nokuhlolwa kokuhlola okungahlinzeka ukuthi kungenzeka ukuthi ingane yakho ine-chromosomal engavamile. Ukuhlolwa kusekelwe eminyakeni yakho futhi kungafaka i-ultrasound, ukuhlolwa kwegazi, i- amniocentesis , nezinye izivivinyo ezingenasidingo ezincane. Ngokuvamile kwenziwa ngeviki le-15 lokukhulelwa kwakho.
> Umthombo:
> I-National Human Genome Research Institute: Izikhungo Zikazwelonke Zempilo. "Ukungahleleki kwe-Chromosomal." I-Bethesda, e-Maryland; ibuyekezwe ngoJanuwari 6, 2016.