Okweqile okuxhumene nobulili

Izifo ezixhumene nocansi zidluliselwa emindenini ngenye yama-chromosomes we-X noma we-Y. I-X ne-Y ngama-chromosomes ocansi.

Ifa eliqavile livela lapho isakhi esingajwayelekile somzali oyedwa sidala isifo, noma ngabe ufuzo olufanayo oluvela komunye umzali lujwayelekile. Kubusa isakhi esingajwayelekile.

Kepha efeni eliphindaphindwayo, zombili izakhi zofuzo ezifanayo kufanele zingavamile ukudala izifo. Uma kuphela isakhi sofuzo kulaba bobabili singejwayelekile, lesi sifo asenzeki noma simnene. Umuntu onofuzo olulodwa olungavamile (kodwa azikho izimpawu) ubizwa ngokuthi umphathi. Abathwali bangadlulisela izakhi zofuzo ezingavamile ezinganeni zabo.

Igama elithi "i-recessive exhumene nobulili" kaningi libhekisa kokuphindaphinda okuxhunywe ku-X.

Izifo eziphindaphindekayo ezixhunywe ku-X zivame ukwenzeka kwabesilisa. Abesilisa bane-X chromosome eyodwa kuphela.Isakhi esisodwa sofuzo kuleyo X chromosome sizodala lesi sifo.

I-chromosome Y enye ingxenye ye-XY gene pair kowesilisa. Kodwa-ke, i-chromosome ye-Y ayinazo izakhi zofuzo eziningi ze-X chromosome. Ngenxa yalokho, ayivikeli eyeduna. Izifo ezinjenge-hemophilia ne-Duchenne muscular dystrophy zivela kuhlobo oluphindaphindiwe ku-X chromosome.

IZIMO EZIJWAYELEKILE

Ekukhulelweni ngakunye, uma umama ethwala isifo esithile (une-X chromosome eyodwa kuphela engajwayelekile) futhi ubaba akayena othwala lesi sifo, umphumela olindelekile yile:

• 25% amathuba omfana ophilile
• 25% ithuba lomfana onesifo
• 25% amathuba entombazane enempilo
• Amathuba angama-25% wentombazane yokuphatha ngaphandle kwesifo

Uma ubaba enalesi sifo futhi umama engeyena othwala, imiphumela elindelekile yile:

• Ama-50% amathuba okuba nomfana ophilile
• Ama-50% amathuba okuba nentombazane engenaso lesi sifo ethwala

Lokhu kusho ukuthi akekho noyedwa ezinganeni zakhe ozokhombisa izimpawu zesifo, kepha lesi sici singadluliselwa kubazukulu bakhe.

IZINGXAKI EZIKHONA ZOKUXELANA NEX-X KWABESIFAZANE

Abesifazane bangathola i-X exhunywe yinkinga engapheli, kepha lokhu akuvamile. Kudingeka isakhi esingajwayelekile ku-X chromosome esivela kumzali ngamunye, ngoba owesifazane unama-chromosomes amabili ama-X. Lokhu kungenzeka kulezi zimo ezimbili ezingezansi.

Ekukhulelweni ngakunye, uma umama ethwala futhi ubaba enalesi sifo, imiphumela elindelekile yile:

• 25% amathuba omfana ophilile
• 25% ithuba lomfana onalesi sifo
• 25% ithuba lentombazane ethwele
• 25% amathuba entombazane enalesi sifo

Uma bobabili umama nobaba benesifo, imiphumela elindelekile yile:

• Ithuba elingu-100% lokuthi ingane inalesi sifo, kungaba umfana noma intombazane

Amathuba walezi zimo ezimbili aphansi kakhulu kangangokuba kwesinye isikhathi izifo ezixhunywe ku-X kwesinye isikhathi zibizwa njengezifo zesilisa kuphela. Noma kunjalo, lokhu akulungile ngokwezobuchwepheshe.

Abathwali besifazane bangaba ne-X chromosome ejwayelekile engasebenzi ngokungavamile. Lokhu kubizwa nge- "skewed X-inactivation." Laba besifazane bangaba nezimpawu ezifana nezabesilisa, noma bangaba nezimpawu ezincane kuphela.

Ifa - ngokweqile okuhlobene nocansi; Izakhi zofuzo - ukuguquguquka okuhlobene nocansi; I-X exhumeke ngokweqile

• Izakhi zofuzo

UFeero WG, uZazove P, uChen F. Imvelo yomtholampilo. Ku: Rakel RE, Rakel DP, ama-eds. Incwadi Yezokwelapha Yomndeni. Umhlaka 9. IPhiladelphia, PA: Elsevier Saunders; 2016: isahluko 43.

UGregg AR, uKuller JA. Izakhi zofuzo zabantu namaphethini wefa. Ku: Resnik R, Lockwood CJ, Moore TR, Greene MF, Copel JA, Silver RM, abahleli. ICreasy neResnik's Maternal-Fetal Medicine: Izimiso kanye Nokuzijwayeza. Umhlaka 8. IPhiladelphia, PA: Elsevier; 2019: isahluko 1.

UJorde LB, uCarey JC, uBamshad MJ. Izindlela zamafa ezixhumene nocansi Ku: Jorde LB, Carey JC, Bamshad MJ, ama-eds. I-Medical Genetics. Umhlaka 6. IPhiladelphia, PA: Elsevier; 2020: isahluko 5.

I-Korf BR. Izimiso zofuzo. Ku: IGoldman L, iSchafer AI, ama-eds. Imithi yeGoldman-Cecil. Umhla ka-26. IPhiladelphia, PA: Elsevier; 2020: isahluko 35.