I-Trisomy kwi-chromosome engama-21, okanye i-Down's Syndrome, yindlela exhaphakileyo ye-genomic pathology eyenzeka kuma-1 kwaba-800 abantwana abazalwa. Iingcali zenzululwazi zifumene ukuba lesi sifo ngenxa yokusasazwa kwama-chromosomes ngokungalunganga, okubangelwa isigulane, endaweni yeekopi ezimbini ze-chromosome yesi-21, zintathu. Ukulindela ukubonakala kwe-pathology akunakwenzeka, kuyacaca ukuba enye i-trisomy kwi-chromosome engama-21 ayithethi enye ngaphandle kweengxaki zeengqondo, zomzimba nezokuziphatha eziphazamisa uphuhliso oluqhelekileyo kunye nobukho bomntwana ogulayo.
Ngokumalunga nalokhu ngasentla, kunzima ukugxininisa ukubaluleka kokuxilongwa kwangaphambi kokubeleka, ukuvumela utero ukuba ugqibe umngcipheko we-trisomy 21 ngezibonakaliso zobunjani.
Ukuhlolwa kokuqala kweethathu
Ubhekisela kwiindlela ezingenayo i-invasive kwaye iqukethe i-ultrasound kunye nokuhlalutya kwegazi ngegazi lomama. Ixesha elifanelekileyo lokujonga i-first-child is weeks 12-13.
Ngexesha lokuxilongwa kwe-ultrasound, iingcali ziqwalasela ubungakanani bebala lebala, okuyiphawu lokubonakalisa ukungaqhelekanga. Ngokwemeko, kuxhomekeke kwiphi iiveki yokukhulelwa kunye nesimo esivumelana nayo, uphawu lwe-trisomy 21 lunokuba ukwandiswa kwendawo yekoloni ngaphezu kwama-5 mm.
Ngaloo ndlela, igazi lelo bhinqa liyahlolwa ngamahomoni amabini: i-b-HCG yamahhala kunye ne-RARR-A. Iyunithi yokulinganisa izikhombisi ezifundwayo zithathe i-MoM. Ixabiso elifunyenweyo lifaniswa namaxabiso aqhelekileyo: I-Trisomy 21 ingabonisa izinga lokunyuka kwe-b-hCG engaphezulu kwe-2 M0Ma, kwaye ukuxilongwa kwe-PAPP-A kungaphantsi kwe-0.5MoM.
Nangona kunjalo, ngokusekelwe kwiziphumo zovavanyo lokuqala ngaphambi kokubeletha, akunakwenzeka ukufumana izigqibo ezicacileyo, kuba oku kuluphawu oluthile olungenakuhlala luqwalasela ezinye izinto ezichaphazela izinga la ma hormone. Kuyakwazi ukuthwala kubo: ixesha elichanekileyo lokukhulelwa, ubunzima bomama, ukukhuthazwa kwe-ovulation, ukutshaya.
Ukuhlolwa kwesibini ngaphambi kokubeletha
Kwixesha eliphakathi kweeveki ezi-15 ukuya kwe-20, kwenziwa umzamo wesibini ukufumanisa i-genomic pathology. Eli xesha lithathwa njengolwazi olungakumbi, kuba uphulaphulo oluninzi lunokubonakala ngexesha le-ultrasound. Ngokomzekelo, emntwaneni onama-trisomy kuma-chromosomes angama-21 ahluke kwi-standard: ubude be-humerus kunye ne-femur, ubungakanani bhuloho yempumlo, ubukhulu be-pelal pelvic, kwaye ngamanye amaxesha iimpembelelo ezibonakalayo zenhliziyo, umzila wesisu okanye i-cyst ye-plexus ye-vascular yengqondo.
Igazi lomfazi okhulelweyo lihlolwe kwizinga le-AFP, eliphawulekayo lokuphazamiseka kwesifo se-fetus. Ukuba, ngenxa yesibini yokuphonononga, i-AFP ifumaneke ukuba ingaphantsi kwesiqhelo, oko kungabonisa ubukho be-trisomy kuma-chromosomes angama-21.
Iziphumo ezifunyenweyo zifaniswa neziphumo zovavanyo lokuqala, ukuba ingozi iphezulu ngokwaneleyo, lona wesifazane okhulelwe unikwe ezinye iindlela zokubhalela iimviwo.
Izindlela eziqhelekileyo zokumisela ukungaqhelekanga kwe-chromosomal
Ichanekileyo ngakumbi, kodwa nezindlela eziyingozi ngakumbi zokufumanisa izifo zentlobo:
- i-amniocentesis - ithetha ukubhoboza udonga lwesisu ngesinaliti esincinci kunye nocingo lwe-amniotic fluid, oluphandwa kwixesha elizayo;
- I-choopon biopsy yindlela yokwazisa ngokufanelekileyo. Njengomthetho, isampuli zeeseli ze-villi kunye ne-placenta zenziwa kwiiveki ezi-11 ukuya ku-12, ngokubhoboza isisu esiswini, okanye ngokusebenzisa i-catheter ngokusebenzisa ubulili;
- sampuli yegazi intambo yesampula, ayenziwa ngaphaya kweveki ye-18 yokukhulelwa.
Izindlela ezibandakanyekayo, nangona zivumela ukuzimisela ngokuchanekileyo kobukho be-genomic anomaly, kodwa ngexesha elifanayo lithatha ingozi yokupheliswa kokukhawuleza kokukhulelwa.