Ukuzaliswa kwe-genetic kunokukhokelela kwiziphoso okanye ukuphuphuma komzimba
Ukungaqhelekanga kwe-chromosomal kwenzeka xa umntwana esebenayo inombolo engafanelekanga ye-chromosomes okanye i-chromosomes eyakhiwe yiphutha. Ezi ziqhelo ziyakwazi ukuguqulela ekuphuhlisweni kweziphene zokuzalwa, iziphazamiso ezifana ne-Down syndrome, okanye ukukhulelwa komzimba.
Ukuqonda iGenesis kunye namaCromosomes
Umzimba wakho wenziwe ngamaseli. Phakathi kweseli ngayinye yinucleus, kwaye ngaphakathi kwisucleus ngama-chromosomes.
I-Chromosomes ibalulekile kuba iqulethe iizakhi ezenza iziganeko zakho zomzimba, uhlobo lwakho lwegazi, kwaye nokuba unokuthi uza kuba nezifo ezithile.
Isinye ngasinye kwisitho sineziqulatho ezingama-23 zama-chromosomes - 46 kuzo zonke-eziqulethe i-20,000 ukuya kuma-25,000. Ingxenye yama-chromosomes akho avela kwiqanda likamama kunye nesiqingatha livela kwisidoda sikayihlo.
Kwimihlulo engama-23 yama-chromosomes, ii-paire zokuqala ezingama-22 zibizwa ngokuba ngama-autosomes. Ii-chromosomes ezimbini zokugqibela, okwangoku, zibizwa ngokuba yi-allosomes. Eyaziwa nangokuthi i-chromosomes yobulili, i-allosomes ichonga ngesondo somntu kunye neempawu zesondo. Ibhinqa ine-X i-chromosomes (XX) ngelixa indoda i-X ne-Y chromosome (XY).
I-Chromosomal engavumelekanga kunye nokutshatyalaliswa
I-Chromosomal engafanelekanga yenye yeyona nto iphambili yokukhulelwa kwesisu ngexesha lekota yokuqala. Ekuphumuleni kokuqala, iimpazamo ze-chromosomal zinokuthintela umntwana ukuba aqhubeke ngokuqhelekileyo.
Xa oko kwenzeka, i-immune system iya kuphendula ngokukhawuleza ukuphelisa ukukhulelwa.
Uphando lucebisa ukuba i-chromosomal engafanelekanga isemva kwama-60 ukuya kuma-70 ekhulwini lamathambo angaphambili. Kwiimeko ezininzi, impazamo yinto engabonakaliyo, kwaye umfazi uya kuqhubeka nokukhulelwa okuqhelekileyo.
Inani elininzi lokulahlekelwa ngamathambo kubangelwa luhlobo lwesifo apho kukho iikopi ezintathu ze-chromosome endaweni ezimbini. Oku kubiza i-trisomy. Imizekelo ye- trisomy 16 kunye ne- trisomy 9 , ehlangene kunye neepesenti ezingama-13 zazo zonke i-matriar first-trimester.
Kwezinye iimeko, i-chromosomal engaqhelekanga ingakhokelela kwimeko engavumelekanga ebizwa ngokuba yi- molar pregnancy . Ngexesha lokukhulelwa komzimba, izicubu ezazisetyenziselwa ukuba zibe yintsana kunokuba zikhule ngokungaqhelekanga kwisibeleko. Kukho iintlobo ezimbini zokukhulelwa kwe-molar:
- Ukukhulelwa kwe-molar epheleleyo kubangelwa xa iqanda lingenalo ulwazi lofuzo. Ivelisa i-placenta ekhangeleka njengeqoqo leidiliya ngaphandle komntwana.
- Ukukhulelwa okukhawulezayo kwenzeka xa iqanda litsalwa zizilwanyana ezimbini. Yibangela ukuphuhliswa kombungu onobubi kwaye kaninzi akahlali.
I-Down Syndrome kunye Nezinye i-Chromosomal ezingaqhelekanga
Enye yeengxaki ezidume kakhulu ze-chromosomal yi-Down syndrome ebangelwa ikopi eyongezelelweyo ye-chromosome ebizwa ngokuba yi-chromosome 21. Kungenxa yesi sizathu sokuba sibhekisela kwingxaki njengesi-trisomy 21.
Ezinye zeendlela eziqhelekileyo ze-Down Syndrome zincinci, isantya esenyukayo kwamehlo, i-tone ephantsi ye-muscle, kunye ne-deep crease phakathi kwetendeni.
Omnye wabantwana abangama-691 base-US uzalwa nge-Down syndrome.
Isizathu sengxaki asiyikucaca ngokupheleleyo, kodwa izazinzulu ziye zaphawula, phakathi kwezinye izinto, unxibelelwano oluqhelekileyo phakathi kobudala bomama kunye nophuhliso lwe-syndrome. Umngcipheko uboniswe ukwandisa ngokukhawuleza njengowesifazane oseminyaka, ukusuka kwi-1,500 kwiminyaka engama-20 ukuya kweyesi-50 ukuya kwi-43 ubudala.
Ukongeza kwi-trisomy 21, kukho ezinye izifo ezinxulumene nobukho bechromosome eyongezelelweyo. Oyintloko phakathi kwabo:
- I-Trisomy 18, eyaziwa nangokuthi i-Edwards syndrome, iyenzeka kwenye ye-2,500 yokukhulelwa kunye nokuba ngowama-6,000 azalwa ku-US Le disorder ibonakala ngokusweleka okuphantsi, intloko encinci, kunye nezinye izinto ezingasongela ubomi. I-Edwards syndrome ayinayo unyango kwaye idla ngokufa ngaphambi kokuzalwa okanye kunyaka wokuqala wobomi.
- I-Trisomy 13, eyaziwa nangokuthi yi-Patau syndrome, inokubangela ukukhubazeka kwengqondo kunye nokukhubazeka kweentliziyo, amehlo angaphiliyo, iminwe okanye iminwe engaphezulu, umlomo ococekileyo, kunye nengqondo okanye umgogodlo ongaqhelekanga. I-Patau syndrome iyenzeka kwenye yee-16,000 zokuzalwa, kunye neentsana zihlala zifa ezinsukwini zokuqala okanye kwiiveki zobomi.
- I-Klinefelter syndrome, eyaziwa nangokuthi i-XXY syndrome, yiphumo le-X ye-chromosome emadodeni. Inxulumene namazinga aphezulu okuthotywa kunye nokungaxhatshali ngokwesondo. Ngokuqhelekileyo iyaqhubeka ingabonwa kuze kube yinkathi yobushushu xa ibonakaliswa ngumzimba onobuthakathaka, ubude obude, ubuncinane beenwele zomzimba kunye ne-genitalia encinci.
Ngokwahlukileyo, ukongezwa kwe-Y eyongezelelweyo kumadoda (i-XYY) okanye i-X eyongezelelweyo kuma-females (XXX) ayiphumeli naziphi na iimpawu zomzimba okanye iimfuno zezempilo. Nangona abanye ba bantwana beba nobunzima bokufunda, bahlala bekhula ngokuqhelekileyo kwaye banako ukukhulelwa abantwana.
Uvavanyo lweChromosomal
Ukufikelela ekupheleni kwekota yakho yokuqala, unokukhetha ukuba ube novavanyo lokuhlola okuza kukunika ithuba lokuba umntwana wakho abe ne-chromosomal engavamile. Uvavanyo lu sekelwe kwiminyaka yakho kwaye lunokufaka i-ultrasound, iimvavanyo zegazi, i- amniocentesis kunye nezinye iimviwo ezingenakuncinci. Ngokuqhelekileyo kwenziwa ngeveki ye-15 yokukhulelwa kwakho.
> Umthombo:
> I-National Human Genome Research Institute: iiNational Institutes of Health. "I-Chromosomal engavumelekanga." EBethesda, eMaryn; hlaziywa ngoJanuwari 6, 2016.