Umjikelezo olilifa urea engaqhelekanga

Umjikelo we-urea ojikeleze ngokungaqhelekanga yimeko ezuzwe njengelifa. Ingabangela iingxaki ngokususwa kwenkunkuma emzimbeni kumchamo.

Umjikelo we-urea yinkqubo apho inkunkuma (i-ammonia) isuswe emzimbeni. Xa usitya iiproteni, umzimba uzaphula ube ziiamino acid. I-Ammonia iveliswa kwi-amino acid eseleyo, kwaye kufuneka isuswe emzimbeni.

Isibindi sivelisa iikhemikhali ezininzi (ii-enzymes) ezitshintsha i-ammonia zibe yifom ebizwa ngokuba yi-urea, enokususwa ngumzimba kumchamo. Ukuba le nkqubo iphazamisekile, amanqanaba e-ammonia aqala ukunyuka.

Iimeko ezininzi ezizuze ilifa zinokubangela iingxaki ngale nkqubo yokususa inkunkuma. Abantu abanengxaki yokujikeleza i-urea bane-gene engalunganga eyenza ii-enzymes ezifunekayo ukophula i-ammonia emzimbeni.

Ezi zifo zibandakanya:

• Argininosuccinic aciduria
• Ukusilela kweArginase
• Ukusilela kweCarbamyl phosphate synthetase (CPS)
• ICitrullinemia
• Ukusilela kwe-N-acetyl glutamate synthetase (NAGS)
• Ukusilela kwe-Ornithine transcarbamylase (OTC)

Njengeqela, ezi ngxaki zenzeka kwi-1 kwi-30,000 yeentsana. Ukusilela kwe-OTC yeyona nto ixhaphakileyo kwezi ngxaki.

Amakhwenkwe ahlala echaphazeleka kukusilela kwe-OTC kunamantombazana. Amantombazana akafane achaphazeleke. La mantombazana achaphazelekayo aneempawu ezibukhali kwaye anokusihlasela esi sifo ebomini.

Ukufumana ezinye iintlobo zokuphazamiseka, kuya kufuneka ufumane ikopi engasebenziyo yofuzo kubazali bobabini. Ngamanye amaxesha abazali abazi ukuba bayayiphatha imfuza de umntwana afumane ingxaki.

Ngokwesiqhelo, umntwana uqala ukuba ngumongikazi kakuhle kwaye ubonakala eqhelekileyo. Nangona kunjalo, ngokuhamba kwexesha usana lukhula ngendlela engalunganga yokutya, ukugabha kunye nokozela, okunokuthi kube nzulu kangangokuba kube nzima ukuba umntwana avuswe. Oku kwenzeka rhoqo kwiveki yokuqala emva kokuzalwa.

Iimpawu zibandakanya:

• Ukudideka
• Ukunciphisa ukutya
• Ungakuthandi ukutya okuneeprotein
• Ukwanda kokulala, ubunzima bokuvuka
• Isicaphucaphu, ukugabha

Umboneleli wezempilo uhlala echonga ezi ngxaki xa umntwana eselusana.

Iimpawu zinokubandakanya:

• Ii-amino acid ezingaqhelekanga egazini nasemchameni
• Inqanaba elingaqhelekanga le-orotic acid egazini okanye kumchamo
• Inqanaba eliphezulu le-ammonia yegazi
• Inqanaba eliqhelekileyo leasidi egazini

Uvavanyo lunokubandakanya:

• Irhasi yegazi ejikelezayo
• Igazi ammonia
• Iswekile yegazi
• Iplasma amino acid
• Ukuchama iiacidi eziphilayo
• Uvavanyo lwemfuzo
• Isibindi se-biopsy
• I-MRI okanye i-CT scan

Ukunciphisa umda kwiprotheyini ekutyeni kunokunceda ekunyangeni oku kuphazamiseka ngokunciphisa inani lenkunkuma ye-nitrogen eveliswa ngumzimba. (Inkunkuma ikwimo yeammonia.) Iifomula ezizodwa zeeprotein ezisezantsi kunye neentsana ziyafumaneka.

Kubalulekile ukuba umboneleli akhokele ukutya kweeprotein. Umboneleli unokulinganisela isixa seprotein umntwana ayifumanayo ukuze yanele ukukhula, kodwa ayonelanga ukuba ibangele iimpawu.

Kubaluleke kakhulu kubantu abanezi ngxaki ukuba banqande ukuzila ukutya.

Abantu abanomjikelo we-urea yokungaqhelekanga kufuneka balumke kakhulu phantsi kwamaxesha oxinzelelo lomzimba, njengaxa benesifo. Uxinzelelo, olufana nomkhuhlane, lunokubangela ukuba umzimba uziphule phantsi iiproteni zawo. Ezi proteni zongezelelekileyo zinokwenza ukuba kube nzima kumjikelo ongaqhelekanga we-urea ukususa imveliso.

Yenza isicwangciso kunye nomboneleli wakho xa ugula ukunqanda zonke iiproteni, usele iziselo eziphezulu ze-carbohydrate, kwaye ufumane ulwelo olwaneleyo.

Uninzi lwabantu abanengxaki yokujikeleza kwe-urea baya kudinga ukuhlala esibhedlele ngaxa lithile. Ngamaxesha anjalo, banokunyangwa ngamayeza anceda umzimba ukuba ususe inkunkuma ene-nitrogen. I-Dialysis inokunceda ukususa umzimba we-ammonia egqithileyo ngexesha lokugula kakhulu. Abanye abantu banokufuna ukufakelwa kwesibindi.

RareConnect: Urea Cycle Disorder Uluntu olusemthethweni- www.rareconnect.org/en/community/urea-cycle-disorders

Ukusebenza kakuhle kwabantu kuxhomekeke:

• Yeyiphi i-urea ejikelezayo engaqhelekanga abanayo
• Inzima kangakanani
• Kufunyenwe kwangoko kangakanani
• Bakulandela ngokusondeleyo kangakanani ukutya okuthintelwe yiprotein

Iintsana ezichongiweyo kwiveki yokuqala yobomi kwaye zinxibe iproteni ethintelwe kukutya kwangoko zinokwenza kakuhle.

Ukuncamathisela kwisondlo kunokukhokelela kubukrelekrele obuqhelekileyo babantu abadala. Ukuphindaphinda ukungalandeli ukutya okanye ukuba neempawu ezibangelwa luxinzelelo kunokukhokelela kukudumba kwengqondo kunye nokonakala kwengqondo.

Uxinzelelo olukhulu, njengokuhlinzwa okanye iingozi, kunokuba nzima kubantu abakule meko. Unonophelo olukhulu luyafuneka ukunqanda iingxaki ngala maxesha.

Iingxaki zinokubandakanya:

• Coma
• Ukudideka kunye nokudideka ekugqibeleni
• Ukufa
• Ukunyuka kwinqanaba le-ammonia yegazi
• Ukudumba kwengqondo

Uvavanyo lokukhulelwa luyafumaneka. Ukuvavanywa kwemfuza ngaphambi kokuba kufakwe umbungu kunokufumaneka kwabo basebenzisa i-vitro ukuba isizathu semfuza siyaziwa.

Isazi sokutya kubalulekile ukunceda ukucwangcisa kunye nokuhlaziya ukutya okunesithintelo kwiiprotheyini njengoko umntwana ekhula.

Njengakwizifo ezininzi ezizuzwe njengelifa, ayikho indlela yokuthintela ezi ngxaki ekukhuleni emva kokuzalwa.

Ukusebenzisana phakathi kwabazali, iqela lezonyango, kunye nomntwana ochaphazelekayo ukulandela ukutya okumiselweyo kunokunceda ukuthintela ukugula kakhulu.

Ukungaqheleki komjikelo we-urea - ilifa; Umjikelo we-Urea-ilifa elingaqhelekanga

• Umjikelo weUrea

IKliegman RM, iSt Geme JW, iBlum NJ, i-Shah SS, iTasker RC, uWilson KM. Iziphene kwimetabolism yeeamino acid. 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: isahl. 103.

IKonczal LL, iZinn AB. Iziphoso ezizelwe kwimetabolism. Ku: UMartin RJ, uFanaroff AA, uWalsh MC, ii-eds. UFanaroff kunye noMartin's Neonatal-Perinatal Medicine. Ngomhla we-11. IPhiladelphia, PA: Elsevier; 2020: isahluko 90.

I-Nagamani SCS, i-Lichter-Konecki U. Iimpazamo zokuzalwa ze-urea synthesis. Ku: Swaiman KF, Ashwal S, Ferriero DM, et al, ii-eds. I-Swaiman's Pediatric Neurology: Imigaqo kunye nokuziqhelanisa. Umhla wesi-6. IPhiladelphia, PA: Elsevier; Ngo-2017: isahluko 38.