http___manastirea-crasna.com_recesivna-hipertenzija-gen.php_1.xml
1.1 2.1 2.2 3.1 3.2 3.3 3.4 4.1 4.2 5.1 5.2 6.1 7.1 8.1 9.1 9.2 9.3 10.1 10.2 10.3 11.1 12.1 13.1 14.1 15.1 16.1 16.2 16.3 16.4 16.5 17.1 17.2 17.3 17.4 17.5 18.1 19.1 19.2 19.3 20.1 20.2 20.3 20.4 20.5 20.6 21.1 21.2 22.1 23.1 23.2 23.3 23.4 23.5 24.1 24.2 24.3 24.4 24.5 24.6 25.1 25.2 25.3 25.4 26.1 27.1 27.2 27.3 28.1 29.1 30.1 30.2 30.3 30.4 30.5 30.6 30.7 30.8 31.1 32.1 32.2 32.3 32.4 32.5 33.1 34.1 34.2 34.3 35.1 36.1 36.2 37.1 38.1 38.2 38.3 38.4 38.5 38.6 38.7 39.1 40.1 40.2 41.1 41.2 41.3 41.4 42.1 43.1 43.2 43.3 44.1 44.2 45.1 46.1 47.1
Overview Vascular malformation of the brain (VMB) is an inflammation of blood vessels (Vasculitis) in the brain, caused when the immune system attacks blood vessels. Reasons for this happening can be due to a reaction to certain medicine, an infection, or other disease; the root cause is still unknown. Vasculitis can affect arteries, veins, and capillaries. Arteries are vessels that carry blood from the heart to the body’s organs. Veins are the vessels that carry blood back to the heart. Capillaries are tiny blood vessels that connect the small arteries and veins. This inflammation can harm veins, capillaries, and arteries. Veins carry blood to the heart; capillaries are small blood vessels connecting small arteries and veins; and arteries transfer blood from the heart to the rest of the body. VMB is also a collective term for ranging conditions involving blood vessels in the brain. These conditions include vein of Galen malformations, telangiectasias, venous angiomas (VAs), Cavernous malformations, and arteriovenous malformation. When a blood vessel becomes inflamed, it can: - Taper, making it harder for blood to move through - Entirely close movement, so blood cannot travel - Bulge from over stretching, weakening it. This is referred to as an aneurysm. If it ruptures, it can cause dangerous internal bleeding. - Symptoms of vasculitis can vary, but usually include nausea, fever, swelling and a general sense of sickness. The purpose of treatment is to stop any inflammation. Medicines like certain steroids can occasionally stop inflammation. Commonly Associated With - Occult Intracranial Vascular Malformations - Intracranial Vascular Malformations - Cerebral Malformations, Vascular Causes There is a strong genetic cause in two forms of VMB. These are cavernous hemangiomas and telangiectasias cases. A Genetic factor exists but is much weaker in arteriovenous malformation of the brain (AVM). In each of these cases, the condition is passed as an autosomal dominant trait. This gives a strong case connected to the chromosomes not tied to the sex chromosomes. Humans typically have 46 chromosomes. These are pairs and each pairs from 1 to 22. Sex chromosomes labeled “X” and “Y”. People born male at birth have an X and Y chromosome, and people born female have 2 X chromosomes. Genetic diseases come from a total combination of gene traits on a chromosome passed down from both parents. Dominant And Recessive Genetic Disorders A dominant genetic disorder happens when one abnormal gene is only needed for the condition to be present. An abnormal gene can be the outcome of a new gene mutation, or can be passed down from either parent. The risk of passing an abnormal gene down to a child is 50%, regardless of sex, per pregnancy A recessive genetic disorder happens when an abnormal gene for the same trait is passed down to a child. Examples of this include sickle cell anemia and cystic fibrosis. Being passed down one normal gene and one abnormal gene makes you a carrier but does not necessarily mean you have the disorder. Having two carrier parents makes a child’s chance of being a carrier of that specific disorder by 25%. As well, this makes that child have a 25% of having two normal genes and not a carrier. This is constant between females and males. A child’s likelihood of obtaining a recessive genetic condition increases more if one or both parents are either carriers or are affected by a specific disorder. However, it is important to know that all people carry some abnormal genes. X-linked Genetic Disorders X-linked recessive genetic disorders are vascular malformations of the brain that come from an abnormal gene on an X chromosome. People born female have two X chromosomes. However, one of those X chromosomes is in-activated and all of the genes on that chromosome are not functioning. People born female with a disease gene on one of their X chromosomes are a carrier for that condition. Carriers typically do not have symptoms because it is generally affected by the X chromosome with the abnormal gene that is inactive. A person born male has one X chromosome. If this person inherits an X chromosome with a disease gene, they will most likely have the disease. People born male with X-linked disorders pass the disease gene to all of their female bron children. These children will then be carriers. A male born person cannot pass an X-linked gene to male born child because people with X and Y chromosomes will always pass down their Y chromosome instead of their X chromosome to male born children. Female carriers of an X-linked disorder have a 25% chance with each pregnancy to have a female born carrier, like themselves, a 25% chance to have a non-carrier female born child, a 25% chance to have a male born child affected with the disease, and a 25% chance to have an unaffected male born child. X-linked dominant disorders originate from an abnormal gene on the X chromosome. However, these are rare conditions. People with two X chromosomes who have an abnormal gene are generally affected by the disease. People with an X and Y chromosome and have an abnormal gene are more severely affected, and many of these people do not survive with x-linked dominant disorders. General Onset Vascular malformations of the brain may cause headaches, seizures, strokes, or bleeding in the brain (cerebral hemorrhage). Some researchers believe that the type of malformation determines the symptoms and progression of the disease. Other researchers believe that only the severity rather than the type of malformation is important. Specific Symptoms For Each Condition Arteriovenous malformations (AVM): AVMs affect veins, arteries, and middle-sized vessels. Here, arteries and veins connect directly, instead of connected through fine capillaries. These abnormal “feeding” arteries continually enlarge, and as a result, the “draining” veins expand as well. The brain tissue between these vessels grows atrophied, or rigid. This becomes a full network of fine fibers named fibrils. Flattened cells fill these and calcify the fibrils. These draw blood away from the brain and cause brain cell atrophy. Hemorrhages or seizures are common side effects of AVMs. Cavernous malformations (CM): CMs show unusually large areas of blood-filled spaces. A cavernous hemangioma acts like a “blood sponge” that douses up blood between capillaries and larger cavern-like spaces. These are slow to fill spaces. There is not typically any brain tissue in these spaces. Hemorrhages or seizures are also common with CMs. Venous angiomas (VA): VAs involve enlarged, tangled, and twisted veins that vary in size but do not involve the arteries. These growths cites then often follow after the capillary stage of the vessel, post-capillary malformation. The defect appears as a connection of small veins that meet to form part of a larger vein (trunk). Telangiectasias: These are malformations that come from dilated capillaries. These enlarged capillaries are small pink-to-red spots that apear throughout the body, like in the eyes, face, and membranes that cover the spinal chord, brain, and mucous membranes. Vein of Galen malformations (VGM): VGMs begin while the embryo is developing. The vein of Galen is located under the cerebral hemispheres and drains the forward and central regions of the brain into the sinuses. This happens when the head does not develop surrounding tissue around the vein of Galen and lacks a normal fibrous wall. And so, the vein of Galen looks free-floating in the sinus fluids. If pressure increase in the vein of Galen, it changes from a cylinder to sphere shape. These changes follow with abnormal fetal blood circulation. And then in extreme conditions, there may be cardiac failure or brain swelling occur (hydrocephalus). Treatment Current treatment options vary according to the location and severity and of a malformation. Though, surgical removal and irradiation currently the most common ways to treat VMBs. In some cases, treatment may not be necessary. However, recently introduced techniques involve particle beam and stereotaxic radio-surgery. Genetic counseling may be of benefit for patients and their families if they have a hereditary form of this disorder. Other treatment is symptomatic and supportive. Other Information Vascular malformations of the brain affect males and females in equally. A hereditary form of cavernous malformations tends to occur more in people of Latin-American descent. Arteriovenous malformations happen generally more frequently in people with XY chromosomes. Symptoms of the following disorders can be similar to those of vascular malformations of the brain. Comparisons may be useful for a differential diagnosis: - Moyamoya disease - Cerebral aneurysm - Cerebrovascular accident (stroke)
1.1 2.1 3.1 3.2 3.3 3.4 4.1 5.1 6.1 6.2 7.1 8.1 9.1 10.1 11.1 12.1 12.2 13.1 14.1 14.2 15.1 15.2 16.1 16.2 17.1 17.2 18.1 19.1 19.2 19.3 20.1 20.2 21.1 21.2 22.1 23.1 23.2 24.1 24.2 24.3 25.1 25.2 25.3 26.1 27.1 27.2 27.3 28.1 29.1 30.1 30.2 30.3 30.4 30.5 31.1 32.1 33.1 33.2 33.3 34.1 34.2 35.1 36.1 36.2 36.3 36.4 36.5
Recesivna hipertenzija gen Cistična fibroza, anemija srpastih stanica Xvezan Obiteljski rahitis, nasljedni nefritis Daltonizam, hemofilija Skup gena zovemo genotip. Sve nasljedne osobine određene su genima. Neke osobine, kao boja kose, razlikuju ljude međusobno. Nenormalne osobine koje iskazuju nenormalni geni mogu uzrokovati nasljedne bolesti. Monogenske bolesti bolesti jednog gena Učinak monogenskih bolesti ovisi o tome je li gen dominantan, recesivan ili smješten na X kromosomu Xvezan. Budući da svaki gen uvjetuje proizvodnju određenog proteina, jedan nenormalni gen dovest će do recesivna hipertenzija gen jednog nenormalnog proteina ili nenormalne količine jednog proteina, što može dovesti do nenormalne funkcije stanice i konačno do fizičkih promjena ili promjena tjelesnih funkcija. Siguran lijek za hipertenziju - manastirea-crasna.com - 4 Geni koji nisu X-vezani Utjecaj što ga proizvede jedan nenormalni gen na autosomnom kromosomu može biti deformitet, bolest ili sklonost razvoju određenih bolesti. Slijedeća načela možemo općenito primijeniti na osobine određene dominantnim genom: Osobe s tom osobinom imaju barem jednog roditelja s istom osobinom, osim u slučaju kad je svojstvo posljedica nove mutacije. Nenormalne genetske osobine češće su posljedica nove mutacije, nego naslijeđene od roditelja. - Vysoký spodní tlak léčba - Hipertenzija s proteinurijom - Humana hipertenzija određena je dominantnim autosomnim genom - Prepoznati hipertenziju kao dominantnu ili recesivnu Osobe koje nemaju nenormalnu osobinu, čak i ako njihova djeca imaju tu osobinu, nisu nosioci nenormalnog gena i ne mogu ga prenijeti na potomstvo. Muškarci i žene imaju gotovo recesivna hipertenzija gen vjerojatnost da budu nositelji nenormalnog svojstva. Nenormalnost može, i najčešće jest, ispoljena u svakoj generaciji. Slijedeća načela možemo općenito primjeniti na osobine određene recesivnim genima: Svatko s tom osobinom ima roditelje koji imaju gen, ali ni jedan roditelj ne mora imati osobinu. Mutacije najčešće ne dovode do iskazivanja osobine. Kad hipertenzija pušač roditelj ima izraženu osobinu, a drugi ima jedan recesivan gen, ali ne iskazuje osobinu, pola njihove djece će vjerojatno iskazivati osobinu, ostali će biti nosioci s jednim recesivnim genom. Ako roditelj bez nenormalne osobine nema nenormalni recesivni gen, ni jedno dijete neće iskazivati nenormalnu osobinu, ali će sva djeca naslijediti nenormalan gen od drugog roditelja koji mogu prenijeti na svoje potomstvo. Osobe koje ne iskazuju nenormalnu osobinu, a imaju djecu s takvom osobinom, vjerojatno imaju jedan nenormalni gen. Nenormalnost se može pojaviti u svakoj generaciji, ali najčešće se ne pojavljuje osim ako oba roditelja imaju ispoljeno nenormalno svojstvo. Nasljeđivanje nenormalnih recesivnih gena Neke bolesti uzrokuje nenormalan recesivan gen. Da bi dobila bolest osoba mora naslijediti dva gena, po jedan od svakog roditelja. Kandidatni geni za hipertenziju Ako oba roditelja imaju jedan nenormalan i jedan normalan gen, oni neće imati bolest, ali će je prenijeti na potomke. Dominantni geni koji uzrokuju teške bolesti su rijetki. Oni maju tendenciju nestanka jer ljudi koji ih imaju često su jako bolesni da bi imali djecu. Međutim, postoji nekoliko iznimki, kao što je Huntingtonova bolest kod koje nastaju teški poremećaji u funkciji mozga koji najčešće nastaju nakon Do tada osoba već može imati djecu. Recesivni geni se iskazuju samo onda kad osoba ima dva takva gena. Osoba s jednim recesivnim genom nema recesivna hipertenzija gen osobinu, ali je nositelj gena za takvu osobinu i može je prenijeti svojoj djeci. X-vezani geni Budući da na Y kromosomu u muškarca ima svega nekoliko gena, geni na jednom X kromosomu Xvezani, spolnovezani geni su bez para recesivna hipertenzija gen zbog toga ispoljeni, bez obzira je su li dominantni ili recesivni. Budući da žene imaju dva X kromosoma, za gene na tim kromosomima vrijede ista pravila kao za gene na autosomnim kromosomima: osim ako oba gena u paru nisu recesivna, ispoljit će se samo dominantni gen. Ako je jedan nenormalni Xvezani gen dominantan, muškarci s tim genom prenijet će recesivna hipertenzija gen na sve svoje kćeri, ali na niti jednog sina. Sinovi osobe s nenormalnim genom dobit će očev Y recesivna hipertenzija gen na kojem se nalazi nenormalan gen. Žene s jednim nenormalnim genom prenijet će nenormalnost polovici svoje djece, muške ili ženske. Ako je nenormalni Xvezani gen recesivan, gotovo svatko s ispoljenom osobinom je muškarac. Muškarci prenose nenormalno svojstvo samo na svoje kćeri, a sve one postaju nositelji. Majke nositelji ne iskazuju svojstva, ali prenose gene na polovicu svojih sinova, koji obično iskazuju nenormalno svojstvo. Ni jedna njena kćer neće iskazivati nenormalno svojstvo, ali će ih pola biti nositelji. U muškaraca, gen za daltonizam dolazi od majke koja je također daltonist ili koja ima normalan vid za boje, ali je nosilac gena za daltonizam. Genske nenormalnosti Muškarci nikad taj gen ne nasljeđuju od oca jer od njega dobivaju Y kromosom. Kćerke očeva daltonista su rijetko i same daltonisti, ali su uvijek nositelji gena za daltonizam. Kodominantno nasljeđivanje U recesivna hipertenzija gen se nasljeđivanju oba gena iskazuju. Jedan primjer je anemija srpastih stanica drepanocitoza : ako osoba ima jedan normalni gen i jedan nenormalni gen, imat će crvene krvne stanice s normalnim i s nenormalnim pigmentom hemoglobinom. Humana hipertenzija određena je dominantnim autosomnim genom Nasljeđivanje nenormalnih recesivnih X-vezanih gena Ako je gen Xvezan pojavljuje se na X kromosomu, ali se ne pojavljuje na Y kromosomu. Bolesti koje su posljedica abnormalnog recesivnog Xvezanog gena obično imaju samo muškarci budući da imaju jedan x kromosom. Žene imaju dva x kromosoma, pa obično imaju normalan gen na drugom kromo somu. Normalni gen je dominantan, pa žene ne razvijaju bolest. Ako otac ima nenormalan gen na svom X kromo somu, a majka dva normalna gena, sve njihove kćeri imat će jedan normalan i jedan nenormalan gen i biti nositelji. Niti jedan sin neće imati nenormalan gen. Prepoznati hipertenziju kao dominantnu ili recesivnu Nenormalni mitohondrijski geni U svakoj stanici nalaze se mitohondriji, sitne strukture koje stanici proizvode energiju. Svaki mitohondrij sadrži kružni kromosom. Nekoliko rijetkih bolesti su uzrokovane nenormalnim genima koji se nalaze na kromosomu mitohondrija. Kad se oplodi jajna stanica, samo mitohondriji iz jajne stanice postaju dijelom zametka; recesivna hipertenzija gen se mitohondriji spermija odbacuju. Zbog toga se bolesti uzrokovane nenormalnim mitohondrijskim genima nasljeđuju od majke. Policistični bubrezi Očevi s nenormalnim mitohondrijskim genima ne mogu prenijeti takve bolesti na svoju djecu. Geni koji uzrokuju rak Stanice raka mogu sadržavati onkogene, što su geni koji uzrokuju karcinom također zvani tumorski geni. Ovi onkogeni se mogu reaktivirati kasnije u životu i mogu uzrokovati rak. Kako dolazi do njihove ponovne aktivacije nije poznato. U ovom poglavlju:.