Imfuza

Imfuza sisifundo selifa, inkqubo yomzali yokugqithisela iintlobo ezithile kubantwana bakhe. Ukubonakala komntu-ubude, umbala weenwele, umbala wesikhumba, kunye nombala wamehlo-kumiselwa yimfuza. Ezinye izinto ezichaphazeleko lilifa:

• Amathuba okufumana izifo ezithile
• Amandla engqondo
• Iitalente zendalo

Uphawu olungaqhelekanga (olungaqhelekanga) oludluliswa kwiintsapho (ezizuzwe njengelifa) zinokuthi:

• Ungabinampembelelo kwimpilo yakho okanye kwintlalo-ntle yakho. Umzekelo, uphawu lunokubangela nje ukuba inwele emhlophe okanye i-earlobe inde kunesiqhelo.
• Unesiphumo esincinci kuphela, njengombala wobumfama.
• Yiba nefuthe elikhulu kumgangatho wakho okanye kubude bobomi.

Uninzi lwezifo zemfuza, ukucebisa ngemfuza kuyacetyiswa. Izibini ezininzi zinokufuna ukufumanisa isifo ngaphambi kokubeleka ukuba omnye wabo unesifo semfuza.

Abantu baneeseli ezinama-chromosomes angama-46. Ezi ziqukethe ii-chromosomes ezi-2 ezichonga ukuba zeziphi na zesini (i-X kunye nee-chromosomes), kunye nama-22 ama-nonsex (autosomal) chromosomes. Amadoda "angama-46, XY" kwaye amabhinqa "angama-46, ama-XX." Ii-chromosomes zenziwe ngemicu yolwazi lofuzo olubizwa ngokuba yi-DNA. I-chromosome nganye inamacandelo e-DNA abizwa ngokuba yimfuza. Imfuza ithwala ulwazi olufunekayo emzimbeni wakho ukwenza iiproteni ezithile.

Isibini ngasinye see-chromosomes ze-autosomal siqulethe i-chromosome enye evela kumama kwaye enye ivela kutata. I-chromosome nganye kwisibini iphethe ulwazi olufanayo; Oko kukuthi, isibini ngasinye se-chromosome sinemfuza efanayo. Ngamanye amaxesha kukho umahluko omncinci wale mfuza. Oku kwahluka kwenzeka ngaphantsi kwe-1% yokulandelelana kwe-DNA. Imfuza enala mahluko ibizwa ngokuba zii-alleles.

Olunye lomahluko unokubangela kuhlobo olungaqhelekanga. Uhlobo olungaqhelekanga lunokukhokelela kwiprotheyini engaqhelekanga okanye kwinani elingaqhelekanga leproteyini eqhelekileyo. Kwisibini see-chromosomes ezizenzekelayo, kukho iikopi ezimbini zohlobo ngalunye, enye ivela kumzali ngamnye. Ukuba olunye lwale mizila yemfuza aluqhelekanga, olunye lunokwenza iprotein eyaneleyo ukuze kungabikho sifo. Xa oku kusenzeka, uhlobo olungaqhelekanga lubizwa ngokuba yi-recessive. Imfuza ehlaziyiweyo kuthiwa izuzwe njengelifa kwi-autosomal recessive okanye kwi-X enxulumene nepateni. Ukuba kukho iikopi ezimbini zemfuza engaqhelekanga, isifo sinokuvela.

Nangona kunjalo, ukuba inye kuphela imfuza engaqhelekanga efunekayo ukuvelisa isifo, ikhokelela kwisifo esibi kakhulu kwilifa. Kwimeko yesifo esixhaphakileyo, ukuba uhlobo olunye olungaqhelekanga luzuzwe njengelifa kunina okanye kutata, umntwana uya kuthi abonakalise esi sifo.

Umntu onentsholongwane engafaniyo ebizwa ngokuba yi-heterozygous yolo hlobo. Ukuba umntwana ufumana isifo esingaqhelekanga sesifo esivela kubazali bobabini, umntwana uya kubonisa eso sifo kwaye uya kuba yi-homozygous (okanye i-heterozygous).

IZINTO EZIBANGELA IMIDA

Phantse zonke izifo zinendawo yemfuza. Nangona kunjalo, ukubaluleka kwelo candelo kuyahluka. Ukuphazamiseka apho izakhi zofuzo zidlala indima ebalulekileyo (izifo zofuzo) zinokuhlelwa njenge:

• Iziphene zohlobo olunye
• Ukuphazamiseka kweChromosomal
• Izinto ezininzi

Ingxaki yohlobo olunye (ekwabizwa ngokuba yiMendelian disorder) ibangelwa sisiphene kuhlobo oluthile. Iziphene zofuzo olunye zinqabile. Kodwa kuba kukho amawaka amaninzi eengxaki zohlobo olunye ezaziwayo, iimpembelelo zazo ezidibeneyo zibalulekile.

Ukuphazamiseka kohlobo olunye kubonakaliswa yindlela abagqitha ngayo kwiintsapho. Zintandathu iipateni ezisisiseko selifa elinye lomfuzo:

• Autosomal ephezulu
• Ukuhlaziywa ngokuzenzekelayo
• X-enxulumene enkulu
• X edityaniswe kwakhona
• Ilifa elixhumene no-Y
• Ilifa loomama (mitochondrial)

Iziphumo eziqwalaselweyo zemfuza (ukubonakala kwesifo) ibizwa ngokuba yi-phenotype.

Kwilifa eliphambili le-autosomal, ukungaqheleki okanye ukungaqheleki kuhlala kuvela kwisizukulwana ngasinye. Ngalo lonke ixesha umzali ochaphazelekayo, nokuba yindoda okanye ibhinqa, enomntwana, loo mntwana unethuba elingama-50% lokusifumana njengelifa esi sifo.

Abantu abanekopi enye yesifo sofuzo esibizwa ngokuba ngabathwali. Abathwali badla ngokungabi nazimpawu zesi sifo. Kodwa, i-gene inokuhlala ifunyanwa kuvavanyo lweelebhu ezinobuzaza.

Kwilifa eline-autosomal recessive, abazali bomntu ochaphazelekayo abanakusibonisa isifo (bangabathwali). Ngokomndilili, ithuba lokuba abazali abathweleyo banokuba nabantwana abaphuhlisa esi sifo ngama-25% ngokukhulelwa ngakunye. Abantwana abangamadoda nabasetyhini nabo banokuchaphazeleka ngokulinganayo. Ukuze umntwana abenempawu zesifo esihamba ngokuzimela, umntwana kufuneka afumane isakhi esingaqhelekanga kubazali bobabini. Kuba uninzi lokuphazamiseka okuxhaphakileyo kunqabile, umntwana usesichengeni sokonyuka kwesifo ukuba abazali bayazalana. Abantu abadibeneyo banamathuba okuba bazuze i-gene efanayo inqabileyo kwi-ukhokho oqhelekileyo.

Kwilifa elidlulileyo le-X, ithuba lokufumana esi sifo liphezulu kakhulu emadodeni kunabafazi. Kuba ufuzo olungaqhelekanga luqhutywa kwi-X (yabasetyhini) i-chromosome, abesilisa abayidluliseli koonyana babo (abaya kufumana i-Y chromosome kooyise). Nangona kunjalo, bayayidlulisela kwiintombi zabo. Kwabasetyhini, ubukho besiqhelo se-X chromosome buso be-X chromosome kunye nohlobo olungaqhelekanga. Ke, phantse zonke iintombi zendoda echaphazelekayo zibonakala ziqhelekileyo, kodwa zonke ziyiziphatho zofuzo olungaqhelekanga. Ngalo lonke ixesha ezi ntombi zizala unyana, kukho iipesenti ezingama-50 zokuba unyana afumane uhlobo olungaqhelekanga.

Kwilifa le-X elidityanisiweyo, ilifa elingaqhelekanga livela kubantu ababhinqileyo nokuba kukho into eqhelekileyo eyi-X chromosome. Kuba amadoda adlulisa i-chromosome Y koonyana babo, abesilisa abachaphazelekayo ngekhe babachaphazele oonyana. Zonke iintombi zabo ziya kuchaphazeleka, nangona kunjalo. Oonyana okanye iintombi zabantu ababhinqileyo abachaphazelekayo baya kuba namathuba angama-50% okufumana esi sifo.

IMIZEKELO YOKUPHILA KWI-GENE SINGLE

Ukuhlaziywa ngokuzenzekelayo:

• Ukusilela kwe-ADA (ngamanye amaxesha kubizwa ngokuba "yinkwenkwe kwiqamza" isifo)
• Ukusilela kwe-Alpha-1-antitrypsin (AAT)
• ICystic fibrosis (CF)
• IPhenylketonuria (PKU)
• Isifo seanemia

X edityaniswe kwakhona:

• I-Duchenne muscular dystrophy
• IHemophilia A

I-Autosomal ephezulu:

• IHypercholesterolemia eqhelekileyo
• Isifo seMarfan

I-X enxulumene kakhulu:

Zimbalwa kuphela, ezinqabileyo, iingxaki ezinxulumene ne-X. Enye yazo zii-rickets ze-hypophosphatemic, ekwabizwa ngokuba yi-vitamin D -i-rickets ezingapheliyo.

IINGXAKI EZIQHELEKILEYO

Kwiingxaki ze-chromosomal, isiphako ngenxa yokugqithisa okanye ukunqongophala kwemfuza equlethwe kwicandelo lonke le-chromosome okanye le-chromosome.

Ukuphazamiseka kweChromosomal kubandakanya:

• Isifo se-22q11.2 se-microdeletion syndrome
• Isifo esiphantsi
• Isifo seKlinefelter
• Isifo sikaTurner

IINGXAKI ZEMIBA YOKUQALA

Uninzi lwezifo eziqhelekileyo lubangelwa kukudibana kwemfuza emininzi kunye nezinto ezisingqongileyo (umzekelo, ukugula kunina kunye namayeza). Oku kubandakanya:

• Isifo sombefu
• Umhlaza
• Isifo sentliziyo
• Seswekile
• Uxinzelelo lwegazi
• Ukubetha

IZIPHUMO EZINXULUMENE NE-MITOCHONDRIAL DNA

IMitochondria zizakhiwo ezincinci ezifumaneka kuninzi lweeseli zomzimba. Banoxanduva lokuvelisa amandla ngaphakathi kwiiseli. IMitochondria iqulethe iiDNA zabo zabucala.

Kwiminyaka yakutshanje, uninzi lweengxaki lubonakalisiwe ngenxa yotshintsho (utshintsho) kwi-DNA ye-mitochondrial. Ngenxa yokuba i-mitochondria ivela kuphela kwiqanda labasetyhini, uninzi lweengxaki zemichiza ezinxulumene ne-DNA zidluliselwa zisuka kunina.

Ukuphazamiseka okunxulumene ne-DNA yeMitochondrial kunokuvela nakweyiphi na iminyaka. Banempawu ezahlukeneyo kunye neempawu. Ezi ngxaki zinokubangela:

• Ubumfama
• Ukulibaziseka kophuhliso
• Iingxaki zesisu
• Ukuphulukana nokuva
• Iingxaki zesingqi sentliziyo
• Ukuphazamiseka kweMetabolic
• Isiqu esifutshane

Ezinye iingxaki zikwabizwa ngokuba ziingxaki ze-mitochondrial, kodwa azibandakanyi utshintsho kwi-DNA ye-mitochondrial. Ezi ngxaki zihlala zihlala zingenasiphako kwimfuza. Balandela ipateni efanayo yelifa njengezinye iingxaki zemfuza ezizodwa. Uninzi lwee-autosomal recessive.

Homozygous; Ilifa Heterozygous; Iipateni zelifa; Ufuzo nezifo; Ilungelo; Iimpawu zeMfuzo

• Imfuza

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Umqolo BR. Imigaqo yemfuza. Ku: IGoldman L, iSchafer AI, ii-eds. Amayeza eGoldman-Cecil. Ngomhla wama-26. IPhiladelphia, PA: Elsevier; 2020: isahluko 35.

UScott DA, uLee B. Inkqubo yemfuza kunyango lwabantwana. Ku: Kliegman RM, St Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, ii-eds. Incwadi kaNelson yeNcwadi yePediatrics. Umhla wama-21. IPhiladelphia, PA: Elsevier; 2020: isahluko 95.