Aneuploidy yog ib hom kab mob caj ces uas cov kab mob hauv lub cev muaj cov chromosomes txawv txav. Yog xav paub ntxiv txog yuav ua li cas aneuploidy manifests nws tus kheej thiab dab tsi yog vim li cas, cia peb luv luv soj ntsuam cov qauv ntawm ib tug nyob cell, cell nucleus thiab cov chromosomes lawv tus kheej.
Ib me ntsis ntawm txoj kev xav
Raws li koj paub, hauv txhua lub cell somatic ntawm tib neeg lub cev muaj ib txwm muaj 46 chromosomes, uas yog, diploid teeb. Tsuas yog nyob rau hauv cov kab mob cov kab mob no yog ib leeg. Chromosomes nyob rau hauv lub cell nucleus thiab yog ib tug ntev, compacted helix ntawm DNA. DNA, nyob rau hauv lem, muaj monomers - polypeptides. Ib qho kev sib lawv liag ntawm polypeptides txiav txim siab txog cov noob - cov txheej txheem ntawm kev tsim noob neej. DNA muaj tag nrho cov kev pab cuam caj ces rau kev loj hlob ntawm ib tug kab mob.
Hauv cov hlwb uas tsis yog poj niam txiv neej, txhua tus chromosome muaj ib tus muam homologous chromosome zoo sib xws tab sis tsis zoo ib yam li thawj. Thaum lub sij hawm meiosis, cov chromosomes pauv cheeb tsam. Qhov no tshwm sim hu ua "crossover". ATcov chromosome yog qhov txawv ntawm caj npab ntev thiab luv.
Chromosome set
Qhov tag nrho ntawm lub cev chromosomes hu ua karyotype. Nquag, nyob rau hauv tib neeg, raws li twb tau hais lawm, tus karyotype yog sawv cev los ntawm 46 chromosomes, 23 los ntawm txhua tus niam txiv, tab sis ib qho anomaly tshwm sim nyob rau hauv uas karyotype yog nthuav txawv. Qhov teeb meem no hu ua "aneuploidy".
Aneuploidy yog ib hom karyotype uas cov chromosomes tsis sib npaug li qub. Aneuploidy ntawm chromosomes, uas ib chromosome ploj lawm, hu ua monosomy. Yog tsis muaj khub - nullisomy. Yog tias tsis yog ib khub ntawm homologous chromosomes, peb homologous chromosomes tshwm hauv karyotype, ces qhov no yog trisomy. Txhua qhov kev hloov pauv ntawm cov chromosomes ua rau muaj kev loj hlob tsis zoo. Qee tus tuaj yeem ua rau tuag taus.
Aneuploidy ntawm non-sex chromosomes (autosomes)
Muaj ntau yam kab mob caj ces tshwm sim los ntawm aneuploidy. Piv txwv ntawm cov kab mob xws li Down syndrome, Patau syndrome, Edwards syndrome. Tag nrho cov kab mob no yog tshwm sim los ntawm qhov muaj chromosome ntxiv nyob rau hauv ntau homologous khub. Down syndrome yog feem ntau ntawm cov kab mob no. Nws tshwm sim los ntawm kev puas hlwb, kev tsis sib haum xeeb, kev kawm nyuaj.
Txawm li cas los xij, trisomy 21, uas ua rau muaj tus kabmob, tsis cuam tshuam rau lub neej expectancy. Cov chav kawm hauv qee cov tswv yim tuaj yeem pab cov neeg mob ua tiav qee yam kev kawm thiab kev sib raug zoo.
Lwm tus kab mob, Patau syndrome, kuj ua rauaneuploidy. Qhov kev ua txhaum loj no yog tshwm sim ntawm trisomy ntawm 13th chromosome. Cov neeg mob tsis tshua muaj sia nyob mus txog 10 xyoo, ntau dua 80% tuag hauv thawj xyoo ntawm lub neej, tus so raug kev txom nyem los ntawm kev mob hlwb loj heev. Cov menyuam yaus uas muaj tus mob Patau syndrome tau hais tawm microcephaly, feem ntau pom muaj teeb meem hauv lub plawv, corneal clouding, cleft palate, thiab auricles me ntsis deformed.
Qhov laj thawj tseem ceeb ntawm Edwards syndrome kuj yog aneuploidy - trisomy ntawm 18th chromosome. Ntau tshaj 90% ntawm cov menyuam yaus uas muaj tus kab mob no tuag los ntawm lub plawv nres hauv thawj xyoo ntawm lub neej, tus so raug kev txom nyem los ntawm kev puas hlwb loj heev thiab xyaum ua tsis tau.
Trisomy 16 muaj ntau dua li lwm yam aneuploidy. Cov kab mob caj ces no ua rau tuag taus, fetus tuag hauv plab thaum thawj peb lub hlis ntawm cev xeeb tub.
Aneuploidy hauv tib neeg tuaj yeem tshwm sim los ntawm cov kab mob tsis tshua muaj caj ces - Varkani's syndrome, trisomy ntawm 8th chromosome. Cov tsos mob tseem ceeb yog kev puas hlwb, lub plawv tsis xws luag, skeletal anomalies.
Aneuploidy ntawm kev sib deev chromosomes
Ib hom aneuploidy, uas tsis tas yuav ua rau muaj qhov tshwm sim loj, yog trisomy ntawm X chromosome. Qhov teeb meem no tshwm sim tsuas yog rau cov poj niam. Trisomy ntawm X chromosome feem ntau tshwm sim - hauv 0.1% ntawm cov poj niam. Tus kab mob no yuav tsis tshwm sim hauv lub neej, uas tshwm sim li ntawm 30% ntawm cov neeg mob. Qhov seem 70% yog tus cwj pwm los ntawm cov tsos mob hauv qab no: dyslexia, agraphia, kev hais lus thiab kev txav mus los. Cov tsos mob siv nyob rau hauv xws li mob yog heev zoo thiabpab tshem tawm cov tsos mob no tag nrho lossis ib nrab.
Lwm yam tsis txaus ntseeg ntsig txog tus lej ntawm kev sib deev chromosomes yog qhov hnyav dua. Cov no suav nrog Shereshevskoro-Turner syndrome, tshwj xeeb ntawm aneuploidy uas tus poj niam lub karyotype tsuas muaj ib qho X chromosome xwb tsis yog ob qho tib si. Cov tsos mob - kev puas hlwb retardation, luv luv stature, impaired kev loj hlob ntawm qhov chaw mos, ib tug me me daim ntawv ntawm kev puas hlwb retardation yog ua tau.
Tseem muaj lwm yam mob hnyav tshwm sim los ntawm aneuploidy. Qhov no yog Klinefelter's syndrome - muaj ib lossis ntau ntxiv X lossis Y chromosomes hauv cov txiv neej. Cov tsos mob tsis tshwm sim txog thaum pib ntawm kev puberty. Yuav luag ib nrab ntawm cov neeg mob tsis muaj tsos mob thoob plaws hauv lawv lub neej, thaum lwm tus muaj gynecomastia, rog, thiab muaj menyuam tsis taus. Hauv qee kis, oligophrenia tau sau tseg.
Caus of aneuploidy
Aneuploidy tshwm sim vim qhov tseeb tias thaum lub sijhawm meiosis homologous chromosomes tsis sib cais thiab tsis yog ib qho, ib khub chromosomes tau nkag mus rau hauv gamete lossis tsis muaj. Yog hais tias nyob rau hauv ib gamete tus naj npawb ntawm chromosomes yog ib txwm, thiab nyob rau hauv lwm yam - txawv txav, ces lub karyotype ntawm lub zygote yuav txawv txav.
Kev tsis sib cais ntawm homologous chromosomes tuaj yeem tshwm sim vim muaj kev cuam tshuam ib puag ncig, raug rau co toxins ntawm ntau yam xwm txheej. Tab sis feem ntau yog vim li cas yog kev xeeb tub: hauv cov tsev neeg uas twb muaj tus mob aneuploidy, qhov kev pheej hmoo ntawm kev muaj menyuam nrog karyotype txawv txav yog siab dua cov niam txiv noj qab haus huv.
Frequency
Nws tuaj yeem hais tias qhov kev pheej hmoo ntawm chromosomalCov kab mob aneuploidy yog qhov nruab nrab me me, txij li tag nrho cov kab mob caj ces raug cais raws li qhov tsawg. Qhov tshwm sim tag nrho ntawm kev muaj menyuam nrog karyotype anomaly yog 5% yog tias ob leeg niam txiv noj qab haus huv. Yog hais tias ib tug ntawm cov niam txiv muaj ib tug pathology ntawm karyotype, qhov tshwm sim ntawm tus me nyuam muaj mob yuav nce.
Qhov zaus ntawm aneuploidy nyob ntawm chromosome. Feem ntau pathology ntawm karyotype yog Klinefelter's syndrome, aneuploidy ntawm kev sib deev chromosome, zaus yog 1 ntawm 500 tus menyuam yug tshiab, qhov tsawg tshaj plaws yog Varkani's syndrome, aneuploidy ntawm 8th chromosome, zaus yog 1:50,000.
Kev kho mob
Kev kho mob ntawm aneuploidy ib txwm muaj cov tsos mob. Nrog Shereshevsky-Turner syndrome, kev loj hlob tsawg thiab tsis muaj poj niam txiv neej cov tshuaj hormones tau sau tseg, yog li cov tshuaj anabolic steroids tau siv los kho.
Nyob rau hauv Down's syndrome, kev kho mob raug txo rau cov chav kawm nrog cov neeg mob hauv cov kev pabcuam tshwj xeeb txhawm rau txhim kho kev txawj ntse.
Cov neeg mob uas muaj tus mob Varkani tsis tshua muaj hnub nyoog 20 xyoo dhau los. Thaum lub sij hawm, cov kev hloov anatomical tshiab tshwm sim, kev puas hlwb kev loj hlob. Yog tias tsim nyog, lawv mus rau kev phais mob txhawm rau kho tus mob ntawm tus txha nraub qaum thiab kho kev cog lus.
Yog cov ntxhais uas muaj trisomy X tau ncua kev hais lus, yuav xav tau tus kws kho mob hais lus. Thaum muaj teeb meem nrog kev sau ntawv thiab kev nyeem ntawv, nws tsim nyog hu rau tus kws kho mob tshwj xeeb dyslexia.
Klinefelter's syndrome tsis tas yuav cuam tshuam rau lub neej zoo ntawm cov neeg mob. Muaj tsawg zauscim kev puas hlwb. Nyob ntawm nws qhov degree (lub teeb, nruab nrab, hnyav), ib qho kev cob qhia tus kheej yog tsim. Yog tias gynecomastia, txo qis kev ua haujlwm ntawm kev sib deev, kev xeeb tub tshwm sim, ces lawv mus rau kev kho tshuaj hormone.
Diagnosis
Cov kab mob caj ces ntawm tus menyuam hauv plab tuaj yeem kuaj tau siv ntau txoj hauv kev (kev kuaj mob ultrasound, biochemical marker method).
Ultrasound tuaj yeem kuaj pom Down syndrome thaum ntxov ntawm kev loj hlob ntawm tus menyuam hauv plab.
Kev kuaj mob ua ntej yug menyuam tsis muaj kev cuam tshuam ntawm aneuploidy yog ib txoj hauv kev nyab xeeb thiab raug rau kev txheeb xyuas qhov txawv txav ntawm karyotype. Lub ntsiab lus ntawm txoj kev yog yooj yim - tus kws tshaj lij tshuaj xyuas cov khoom seem ntawm tus menyuam DNA uas nyob hauv niam cov ntshav. Invasive aneuploidy diagnosis yog qhov tseeb dua, tab sis vim tias nws muaj kev pheej hmoo ntawm nchuav menyuam, nws tsuas yog siv los ua qhov kawg nkaus xwb.
Cov laj thawj uas ua rau muaj qhov tshwm sim ntawm aneuploidy
Cov kev tshawb fawb tsis ntev los no tau pom tias muaj qhov sib raug zoo ntawm lub hnub nyoog ntawm leej niam thiab qhov muaj feem yuav muaj menyuam yaus nrog Down syndrome, Patau syndrome lossis Edwards syndrome. Tus poj niam laus dua, nws yuav muaj tus menyuam muaj kab mob txawv txav.
Dab tsi yog yam tseem ceeb ua lub luag haujlwm txiav txim siab hauv kev loj hlob ntawm kev sib deev chromosome aneuploidy tsis paub. Nws yog assumed tias tus yuam sijlub luag hauj lwm nyob rau hauv xws li mob belongs rau heredity.
