Heterozygous ndi mawu ogwiritsidwa ntchito mu ma genetic kufotokozera pamene mitundu iwiri ya jini (yotchedwa alleles) ili pawiri pamalo omwewo (locus) pa chromosome . Mosiyana ndi zimenezo, kugonana ndizochitika pamene pali makope awiri omwe amakhala pamalo omwewo.
Mawu akuti heterozygous amachokera ku "hetero-" amatanthauzira mosiyana ndi "zenizeni" tanthauzo lokhudzana ndi dzira la umuna (zygote).
Kusankha Makhalidwe
Anthu amatchedwa ziwalo za diploid chifukwa ali ndi alleles awiri pa locus aliyense, ndi imodzi yokhala cholowa kuchokera kwa kholo lililonse. Kulemba kwake kwa alleles kumatanthauzira kusintha kwa makhalidwe a munthu.
Chilichonse chimakhala chowopsa kapena chokhazikika. Malamulo akuluakulu ndi omwe amasonyeza khalidwe ngakhale pali kopi imodzi yokha. Zolinga zokhazokha zingathe kudziwonetsera nokha ngati pali makope awiri.
Chitsanzo chimodzi chotere ndi maso a bulauni (omwe ali opambana) ndi maso a buluu (omwe ali ochuluka kwambiri). Ngati mabungwewo ali heterozygous, chiwonongeko chachikulu chidzadziwonekera pafupipafupi, zomwe zimachititsa maso a bulauni. Panthaŵi imodzimodziyo, munthuyo angatengedwe kuti ndi "chonyamulira" cha kupitirira malire, kutanthauza kuti maso a buluu angaperekedwe kwa ana ngakhale ngati munthuyo ali ndi maso a bulauni.
Zolinga zingakhalenso zovuta kwambiri, mtundu wapakati wa choloŵa kumene palibe chilolezo chimasonyezedwa kwathunthu kuposa chimzake.
Chitsanzo cha izi chingaphatikizepo chilolezo chofanana ndi khungu lakuda (limene munthu ali ndi melanin yambiri ) ali ndi phokoso lofanana ndi khungu loyera (lomwe lili ndi kachilombo kochepa) kuti apange khungu kwinakwake.
Kukula kwa Matenda
Pambuyo pa maonekedwe a munthu, kuthamanga kwa heterozygous alleles nthawi zina kumasuliridwa kukhala chiopsezo chachikulu cha zikhalidwe zina monga matenda obereka kapena matenda a autosomal (matenda omwe amachokera kudzera mwa majini).
Ngati phokoso limasinthidwa (kutanthauza kuti ndi lolakwika), matenda amatha kuperekedwa kwa ana ngakhale kholo silikhala ndi zizindikiro za matendawa. Ponena za heterozygosity, izi zikhoza kutenga imodzi mwa mitundu:
- Ngati mabungwewo ali otsika kwambiri, vuto lolakwika likanakhala lopanda malire komanso osadzifotokozera. Mmalo mwake, munthuyo adzakhala chotengera.
- Ngati mabungwewa ali otchuka kwambiri, vuto lolakwika likanakhala lopambana. Zikatero, munthuyo akhoza kapena sangakhudzidwe (poyerekeza ndi kulamulira komwe munthu angakhudze).
Zina zowonjezereka zowonongeka zimangopangitsa munthu kukhala ndi thanzi lachilendo komanso mitundu ina ya khansa . Izi sizikutanthauza kuti munthu adzalandira matendawa; Zimangowonetsa kuti munthuyo ali pachiopsezo chachikulu. Zinthu zina, monga moyo ndi chilengedwe, zimathandizanso.
Kuvutika kwa Gene limodzi
Matenda osakwatirana amtundu umodzi ndi omwe amayamba chifukwa chokhala ndi mutate umodzi m'malo mwa awiri. Ngati mutated allele ndi recessive, munthuyo sangasokonezeke. Komabe, ngati mutated alate ali ndi mphamvu, buku lopangidwa ndi mutated lingapangitseko kupopera mankhwalawa ndipo amachititsa mitundu yochepa ya matenda kapena matenda owonetsa.
Matenda osakwatirana amtundu umodzi ndi osowa. Zina mwa zovuta kwambiri zomwe anthu ambiri amavutika nazo:
- Matenda a Huntington ndi matenda obadwa nawo omwe amachititsa imfa ya maselo a ubongo. Matendawa amayamba chifukwa cha kusintha kwakukulu m'modzi kapena onse awiri a jini wotchedwa Huntingtin .
- Mtundu wa Neurofibromatosis mtundu wa 1 ndi matenda omwe anabadwa nawo omwe minofu ya mitsempha imakula pakhungu, msana, mafupa, maso, ndi ubongo. Chinthu chimodzi chokha chomwe chimafunika kusintha kuti chiyambitse zotsatirazi.
- Mayi achibadwa otchedwa hypercholesterolemia (FH) ndi matenda omwe amabadwa nawo omwe amadziwika ndi ma cholesterol ambiri, makamaka "oipa" a lipoproteins (LDLs). Ndilo vuto lalikulu kwambiri la matendawa, lomwe limakhudza anthu pafupifupi 500.
Munthu yemwe ali ndi vuto limodzi la jini ali ndi mwayi wa 50/50 wopatsira mwanayo kuti azitha kukhala chonyamulira.
Ngati makolo onse awiri ali ndi vuto la kusintha kwambiri kwa magazi, ana awo adzakhala ndi mwayi umodzi wokhala ndi vutoli. Vuto lidzakhala lofanana ndi kubadwa kulikonse.
Ngati makolo onse awiri ali ndi vuto lopanda mphamvu, ana awo amakhala ndi mwayi wokhala ndi chiwerengero chokwanira chokhala ndi zizindikiro (25%). Ambiri amakhala ndi mwayi wokhala ndi zizindikiro ziwiri, komanso 25% (palibe zizindikiro).
Heterozygosity
Heterozygosity ndipadera pomwe pali mitundu iwiri yosiyana kwambiri yomwe imayambitsa matenda. Izi ndizo, zovuta zomwe zimakhala zosiyana ndi mtundu kapena fuko. Mwa iwo:
- Matenda a Tay-Sachs ndi matenda omwe sakhala nawo, omwe amachititsa kuti maselo a mitsempha mu ubongo ndi msana. Ndi matenda osokonezeka kwambiri omwe angayambitse matenda kuyambira ali wakhanda, akukula kapena akuluakulu. Ngakhale Tay-Sachs amayamba chifukwa cha kusintha kwa majini a mthupi la HEXA , ndizomwe zimayambitsa matenda omwe amatenga matenda. Kuphatikiza kwina kumasulira mpaka matenda a ubwana; ena amatembenuza ku matenda oyambirira omwe amayamba.
- Phenylketonuria (PKU) ndi matenda a chibadwa makamaka omwe amakhudza ana omwe chinthu chodziwika kuti phenylalanine chimakhala mu ubongo, kuchititsa kufooka, matenda, ndi kulemala kwaumunthu. Pali mitundu yambiri ya kusintha kwa majini yomwe imagwirizanitsidwa ndi PKU, zomwe zimayambitsa matenda osiyanasiyana.
Matenda ena omwe ma heterozygotes amatha kukhala nawo ndi cystic fibrosis, sickle cell anemia, ndi hemochromatosis (chitsulo chochuluka m'magazi).
Heterozygote Phindu
Ngakhale kuti kachilombo kamodzi kokha kawirikawiri sikakhala ndi matenda, pali malo omwe angapereke chitetezo ku matenda ena. Ichi ndi chodabwitsa chomwe chimatchedwa heterozygote mwayi.
Nthaŵi zina, kusungulumwa kumodzi kumatha kusintha kusintha kwa thupi kwa munthu m'njira yotero kuti munthuyo asagwirizane ndi matenda ena. Zitsanzo mwa izi:
- Matenda a m'thupi la matenda ndi matenda a chibadwa omwe amachititsidwa ndi two alleles alleles. Kukhala ndi alleles kumayambitsa malformation ndi kudzidzidzimutsa kudziwonongera kwa maselo ofiira ofiira. Kukhala ndi chiwerengero chimodzi chokha chingayambitse vuto loipa kwambiri lotchedwa sickle cell khalidwe limene maselo okhawo ali opunduka. Kusintha kwakukulu kumeneku ndikokwanira kuteteza malungo mwa kupha maselo a m'magazi mofulumira kusiyana ndi tizilombo toyambitsa matenda.
- Cystic fibrosis (CF) ndi matenda opatsirana kwambiri omwe angayambitse matenda aakulu m'mapapo ndi m'mimba. Kwa anthu omwe ali ndi homozygous alleles, CF imayambitsa ntchentche, yamakono m'mapapo ndi m'matumbo. Anthu omwe ali ndi heterozygous alleles, zotsatira zomwezo, ngakhale zitacheperachepera, zingachepetse chiopsezo cha munthu ku kolera ndi typhoid fever . Poonjezera kupanga mankhwala osokoneza bongo, munthu saganizira zoopsa za kutsekula m'mimba.
Zotsatira zofananazi zikhoza kufotokoza chifukwa chake anthu omwe ali ndi matenda otchedwa heterozygous alleles of autoimmune disorders akuwoneka kuti ali ndi chiopsezo chochepa cha matenda a chiwindi cha chiwindi cha matenda a hepatitis C.
> Zotsatira:
> Al-Chalabi, A. ndi Almasy, L. (2009) Genetics of Complex Human Diseases: Buku la Laboratory (1st Lab Edition). New York, New York: Zolemba za Cold Spring Harbor Laboratory. ISBN-13: 978-0879698836.
> Genetic Alliance. (2010) Kumvetsetsa Ma Genetics: A District of Columbia Guide kwa Odwala ndi Othandizira Zaumoyo. "Zowonjezera G: Matenda Okhaokha a Gene . " Washington, DC: District of Columbia Dipatimenti ya Zaumoyo. PMID: 23586106.
> Wynbrandt, J. ndi Ludman, M. (2008) The Encyclopedia of Genetic Disorders ndi Birth Defects (3rd Edition). New York, New York: Library ya Health and Living. ISBN-13: 978-0816063963.