{"id":87205,"date":"2026-05-16T05:03:12","date_gmt":"2026-05-16T05:03:12","guid":{"rendered":"https:\/\/www.europesays.com\/cz\/87205\/"},"modified":"2026-05-16T05:03:12","modified_gmt":"2026-05-16T05:03:12","slug":"proc-ma-mala-cast-populace-negativni-krevni-skupinu-kdyz-drtiva-vetsina-planety-ma-typ-pozitivni","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/cz\/87205\/","title":{"rendered":"Pro\u010d m\u00e1 mal\u00e1 \u010d\u00e1st populace negativn\u00ed krevn\u00ed skupinu, kdy\u017e drtiv\u00e1 v\u011bt\u0161ina planety m\u00e1 typ pozitivn\u00ed?"},"content":{"rendered":"

Nez\u00e1visl\u00e1 skupina v\u011bdky\u0148 a\u00a0v\u011bdc\u016f z\u00a0\u010desk\u00fdch i\u00a0zahrani\u010dn\u00edch v\u00fdzkumn\u00fdch instituc\u00ed odpov\u00edd\u00e1 na va\u0161e dotazy. N\u011bkter\u00e9 odpov\u011bdi pak sd\u00edl\u00ed i\u00a0na soci\u00e1ln\u00edch s\u00edt\u00edch Facebook<\/a>, Instagram<\/a>, Threads<\/a>, Bluesky<\/a> a\u00a0zde na M\u00e9diu.<\/p>\n

DotazMo\u017en\u00e1 u\u017e se na to n\u011bkdo v\u00a0minulosti ptal a\u00a0j\u00e1 to p\u0159ehl\u00e9dl, ka\u017edop\u00e1dn\u011b jsem se cht\u011bl zeptat, pro\u010d m\u00e1 mal\u00e1 \u010d\u00e1st populace negativn\u00ed krevn\u00ed skupinu, kdy\u017e m\u00e1 tak\u0159ka drtiv\u00e1 v\u011bt\u0161ina planety typ pozitivn\u00ed.Minutov\u00e1 odpov\u011b\u010fRh faktor je jedn\u00edm z\u00a0nejd\u016fle\u017eit\u011bj\u0161\u00edch krevn\u011b-skupinov\u00fdch syst\u00e9m\u016f, ur\u010dovan\u00fd p\u0159\u00edtomnost\u00ed nebo nep\u0159\u00edtomnost\u00ed antigenu\u00a0D na \u010derven\u00fdch krvink\u00e1ch.Krevn\u00ed skupiny lid\u00ed s\u00a0antigenem\u00a0D ozna\u010dujeme jako pozitivn\u00ed (Rh\u207a) a\u00a0bez n\u011bj jako negativn\u00ed (Rh\u207b).Je mo\u017en\u00e9, \u017ee Rh\u207a mohl v\u00fdvojov\u011b poskytovat ur\u010dit\u00e9 v\u00fdhody, nap\u0159\u00edklad vy\u0161\u0161\u00ed odolnost v\u016f\u010di n\u011bkter\u00fdm nemocem, ale tato hypot\u00e9za nen\u00ed pln\u011b potvrzena.Vysok\u00fd v\u00fdskyt Rh\u207a je v\u00fdsledkem kombinace genetick\u00fdch a\u00a0mo\u017en\u00e1 tak\u00e9 v\u00fdvojov\u00fdch faktor\u016f.Odpov\u011b\u010fCo je na povrchu \u010derven\u00fdch krvinek?<\/p>\n

Rh skupina (tzv. Rhesus faktor) je jeden ze syst\u00e9m\u016f ur\u010dov\u00e1n\u00ed krevn\u00edch skupin a\u00a0spolu se syst\u00e9mem AB0, (kter\u00e9mu jsme se v\u011bnovali u\u017e i\u00a0v jin\u00e9 odpov\u011bdi, viz sekce Dal\u0161\u00ed \u010dten\u00ed) se jedn\u00e1 o\u00a0dva nejd\u016fle\u017eit\u011bj\u0161\u00ed (pro transf\u00faze krve, t\u011bhotenstv\u00ed a\u00a0n\u011bkter\u00e9 medic\u00ednsk\u00e9 z\u00e1kroky)\u00a0[1].<\/p>\n

Rh faktor byl objeven v\u00a0roce 1940\u00a0Karlem Landsteinerem a\u00a0Alexanderem Wienerem p\u0159i v\u00fdzkumu krve makak\u016f rhesus (Macaca mulatta), co\u017e dalo syst\u00e9mu jeho n\u00e1zev [8].<\/p>\n

Tento \u201ekrevn\u011b skupinov\u00fd syst\u00e9m\u201c je ur\u010dov\u00e1n p\u0159\u00edtomnost\u00ed, nebo nep\u0159\u00edtomnost\u00ed antigen\u016f (drobn\u00fdch molekul, nej\u010dast\u011bji protein\u016f) na povrchu \u010derven\u00fdch krvinek. Jedn\u00e1 se o\u00a0vysoce r\u016fznorod\u00fd antigen (doposud bylo zji\u0161t\u011bno v\u00edce ne\u017e 40\u00a0s\u00e9rologicky odli\u0161n\u00fdch Rh antigen\u016f) [1]. Nejzn\u00e1m\u011bj\u0161\u00ed a\u00a0nejd\u016fle\u017eit\u011bj\u0161\u00ed antigen v\u00a0tomto syst\u00e9mu je antigen D. Lid\u00e9, kte\u0159\u00ed maj\u00ed tento antigen D p\u0159\u00edtomn\u00fd na povrchu sv\u00fdch \u010derven\u00fdch krvinek, jsou ozna\u010deni jako Rh pozitivn\u00ed (Rh\u207a), kde\u017eto ti, kte\u0159\u00ed ho nemaj\u00ed, jsou ozna\u010dov\u00e1ni jako Rh negativn\u00ed (Rh\u207b) [1].<\/p>\n

Kdo a\u00a0od koho m\u016f\u017ee p\u0159ijmout krev?<\/p>\n

Nejb\u011b\u017en\u011bj\u0161\u00ed kombinac\u00ed ozna\u010den\u00ed typu krevn\u00ed skupiny u\u00a0lid\u00ed je kombinace syst\u00e9mu AB0\u00a0a\u00a0ur\u010den\u00ed Rh faktoru. Zapisuje se nap\u0159. jako A\u207b nebo AB\u207a.<\/p>\n

Lid\u00e9 s\u00a0krv\u00ed bez antigenu D (Rh\u207b) nemohou p\u0159ij\u00edmat krev jedinc\u016f s\u00a0antigenem D (Rh\u207a), proto\u017ee by si proti antigenu D vytvo\u0159ili protil\u00e1tky a\u00a0darovanou krev by nep\u0159ijali. Naopak jedinci s\u00a0krevn\u00ed skupinou Rh\u207a mohou p\u0159ij\u00edmat krev od Rh\u207b jedinc\u016f, pokud je jinak krevn\u00ed skupina odpov\u00eddaj\u00edc\u00ed (nap\u0159\u00edklad A\u207a m\u016f\u017ee p\u0159ij\u00edmat krev od A\u207b). Rh\u207a jedinci nemaj\u00ed \u017e\u00e1dn\u00fd probl\u00e9m p\u0159ijmout krev bez antigenu D (Rh\u207b), proto\u017ee jejich t\u011blo se nebude br\u00e1nit n\u011b\u010demu, co v\u00a0darovan\u00e9 krvi nen\u00ed.<\/p>\n

R\u016fzn\u00e9 lidsk\u00e9 populace maj\u00ed r\u016fzn\u00e9 \u010detnosti Rh\u207a a\u00a0Rh\u207b jedinc\u016f. Zhruba 90\u00a0% \u010desk\u00e9 populace je Rh\u207a [2]. V\u00a0Evrop\u011b jsou \u010detnosti n\u00e1sleduj\u00edc\u00ed: Rh\u207a 84\u00a0% a\u00a0Rh\u207b 16\u00a0%. V\u00a0africk\u00e9 populaci je Rh pozitivita je\u0161t\u011b \u010dast\u011bj\u0161\u00ed; p\u0159ibli\u017en\u011b Rh\u207a 99,9\u00a0% a\u00a0Rh\u207b pouze 0,1\u00a0% [3].<\/p>\n

Ka\u017ed\u00e1 na\u0161e bu\u0148ka obsahuje 2\u00a0varianty (alely) od ka\u017ed\u00e9ho genu\u00a0\u2013 d\u011bd\u00edme je od rodi\u010d\u016f\u00a0\u2013 jeden od matky a\u00a0jeden od otce. To plat\u00ed i\u00a0pro geny ur\u010duj\u00edc\u00ed krevn\u00ed skupiny. Konkr\u00e9tn\u011b krevn\u00ed faktor Rh (tedy antigen D) je tak\u00e9 ur\u010den geneticky a\u00a0\u0159\u00edd\u00ed ho gen RHD. Tento gen obsahuje n\u00e1vod na tvorbu ur\u010dit\u00e9ho proteinu na povrchu \u010derven\u00fdch krvinek.<\/p>\n

\"\"<\/a>D\u011bd\u011bn\u00ed Rh faktoru m\u00e1 sv\u00e1 pravidla<\/p>\n

Rh faktor se d\u011bd\u00ed podle jednoduch\u00fdch pravidel:<\/p>\n

Rh\u207a (pozitivn\u00ed) je zp\u016fsoben dominantn\u00edm genem (D). Sta\u010d\u00ed m\u00edt jen jednu kopii tohoto genu (DD nebo Dd), a\u00a0\u010dlov\u011bk bude Rh pozitivn\u00ed.<\/p>\n

Rh\u207b (negativn\u00ed) vznikne pouze tehdy, pokud \u010dlov\u011bk zd\u011bd\u00ed dv\u011b recesivn\u00ed alely (dd)\u00a0\u2013 tedy \u017e\u00e1dnou kopii genu D.<\/p>\n

Pokud by nap\u0159\u00edklad p\u0159\u00edtomnost recesivn\u00ed alely d byla ale v\u00a0populaci velmi \u010dast\u00e1 (jako je tomu pr\u00e1v\u011b s\u00a0recesivn\u00ed alelou 0\u00a0v\u00a0syst\u00e9mu AB0), mohl by b\u00fdt v\u00fdskyt krevn\u00edho faktoru Rh\u207b \u010dast\u011bj\u0161\u00ed\u00a0\u2013 ale nen\u00ed tomu tak a\u00a0to mo\u017en\u00e1 z\u00a0n\u011bkolika d\u016fvod\u016f.<\/p>\n

Byla v\u00a0tom n\u011bjak\u00e1 evolu\u010dn\u00ed v\u00fdhoda?<\/p>\n

Evolu\u010dn\u00ed v\u00fdhody: Vysok\u00fd v\u00fdskyt Rh\u207a faktoru v\u00a0populaci sv\u00e1d\u00ed k\u00a0my\u0161lence, \u017ee historicky mohl m\u00edt Rh\u207a faktor pro \u010dlov\u011bka n\u011bjak\u00e9 v\u00fdhody, t\u0159eba vy\u0161\u0161\u00ed odolnost v\u016f\u010di ur\u010dit\u00fdm nemocem (nap\u0159. p\u0159i n\u00e1kaze toxoplasmosou) [4\u20136]. Tyto v\u00fdhody by teoreticky mohly v\u00e9st k\u00a0vy\u0161\u0161\u00ed reproduk\u010dn\u00ed \u00fasp\u011b\u0161nosti lid\u00ed s\u00a0Rh\u207a krv\u00ed (pokud jedinec p\u0159e\u017eil d\u00e9le, m\u011bl vy\u0161\u0161\u00ed pravd\u011bpodobnost m\u00edt v\u00edce potomk\u016f), co\u017e by vysv\u011btlovalo vy\u0161\u0161\u00ed v\u00fdskyt t\u00e9to alely v\u00a0populaci, ale nic z\u00a0toho nen\u00ed v\u011bdou potvrzeno [4\u20136].<\/p>\n

Genetick\u00fd drift a\u00a0efekt zakladatele: V\u011bt\u0161\u00ed vliv by na \u010dast\u011bj\u0161\u00ed v\u00fdskyt Rh\u207a jedinc\u016f mohly m\u00edt genetick\u00e9 procesy, kdy v\u00a0mal\u00fdch populac\u00edch m\u016f\u017ee doch\u00e1zet k\u00a0n\u00e1hodn\u00e9mu zv\u00fd\u0161en\u00ed frekvence ur\u010dit\u00fdch alel, v\u010detn\u011b Rh faktoru [6]. Pokud zakladatel\u00e9 nov\u00e9 populace (nap\u0159\u00edklad migranti, kte\u0159\u00ed os\u00eddlili nov\u00e9 \u00fazem\u00ed) byli p\u0159ev\u00e1\u017en\u011b Rh\u207a, m\u016f\u017ee to v\u00e9st k\u00a0vysok\u00e9 frekvenci Rh\u207a faktoru v\u00a0t\u00e9to nov\u00e9 populaci [6]. Proto tak\u00e9 existuj\u00ed populace, kde se Rh\u207b t\u00e9m\u011b\u0159 nevyskytuje.<\/p>\n

Genetick\u00e1 mutace: P\u016fvodn\u00ed alelou je pravd\u011bpodobn\u011b Rh\u207a a\u00a0varianta Rh\u207b je pravd\u011bpodobn\u011b genetickou odchylkou, kter\u00e1 vznikla evolu\u010dn\u011b a\u017e pozd\u011bji, a\u00a0proto nemus\u00ed b\u00fdt tak moc roz\u0161\u00ed\u0159enou [7]. Op\u011bt se jedn\u00e1 pouze o\u00a0dohady.<\/p>\n

Celkov\u011b lze tedy \u0159\u00edci, \u017ee velmi vysok\u00fd v\u00fdskyt Rh pozitivn\u00edho faktoru je v\u00fdsledkem kombinace genetick\u00fdch a\u00a0mo\u017en\u00e1 tak\u00e9 v\u00fdvojov\u00fdch faktor\u016f, ale doposud nen\u00ed tento jev dopodrobna v\u011bdecky pops\u00e1n.<\/p>\n

Pro Zeptej se v\u011bdce odpov\u00eddala Jana<\/p>\n

Mgr. Jana Jedli\u010dkov\u00e1, Ph.D., Klinika pediatrie a\u00a0d\u011bdi\u010dn\u00fdch poruch metabolismu, 1.\u00a0l\u00e9ka\u0159sk\u00e1 fakulta Univerzity Karlovy a\u00a0V\u0161eobecn\u00e1 fakultn\u00ed nemocnice v\u00a0Praze<\/p>\n

Odbornou revizi poskytla Ing. Mark\u00e9ta Fajfrov\u00e1, \u00dastav molekul\u00e1rn\u00ed genetiky AV \u010cR<\/p>\n

Odpov\u011b\u010f editovali Dr. Ing. Krist\u00fdna Lap\u010d\u00edkov\u00e1, \u00dastav analytick\u00e9 chemie, V\u0160CHT Praha, Mgr. Hedvika \u0160imkov\u00e1 a\u00a0Lud\u011bk Va\u0161ta<\/p>\n

Zdroje<\/p>\n

[1] https:\/\/pubmed.ncbi.nlm.nih.gov\/10627438\/<\/p>\n

[3] https:\/\/doi.org\/10.1016\/C2011-0-07946-2<\/p>\n

[4] https:\/\/doi.org\/10.1371\/journal.pone.0287992<\/p>\n

[5] https:\/\/doi.org\/10.1186\/s12916-024-03520-x<\/p>\n

[6] https:\/\/doi.org\/10.1007\/s00439-012-1147-5<\/p>\n

[7] https:\/\/doi.org\/10.1016\/j.tracli.2006.02.011<\/p>\n

[8] https:\/\/doi.org\/10.1084\/jem.74.4.309<\/p>\n

Zeptej se v\u011bdce<\/p>\n

Projekt Zeptej se v\u011bdce propojuje v\u011bdeckou a\u00a0nev\u011bdeckou ve\u0159ejnost. M\u00e1te-li na v\u011bdce n\u011bjak\u00fd dotaz, zeptejte se n\u00e1s na webu<\/a>nebo soci\u00e1ln\u00edch s\u00edt\u00edch Facebook<\/a>, Twitter<\/a>, Instagram<\/a> \u010di Bluesky<\/a>. L\u00edb\u00ed se v\u00e1m na\u0161e p\u0159\u00edsp\u011bvky? Budeme r\u00e1di, kdy\u017e podpo\u0159\u00edte na\u0161i \u010dinnost: darujme.cz\/projekt\/1209422<\/a><\/p>\n

Foto: Zeptej se v\u011bdce!