We inherit diseases within a family of
not only family relics, letters, memoirs... Diseases to which we are inclined are put in our genetic program at the time of conception.
All components of our health are defined by hereditary predisposition. Whether the fracture or a bruise will become result of falling, depends on heredity: durability of bones is caused by the level of a calcic exchange, and it, in turn, is descended. That is from parents not the “ready“ illness, but violations is transferred to us in structure of fabrics which can cause diseases. So, predisposition to a hypertension, varicosity, hemorrhoids is connected with features of a structure of protein which participates in creation of the fabric forming vessels and muscles. Defects in structure of the collagen necessary for creation of an eye, are guilty in short-sightedness. Atherosclerosis - the main reason warmly - vascular diseases - is caused by deficiency of the cages neutralizing “bad“ cholesterol. The obesity reason - at all not a gene, but metabolic disorders. And the allergy is a result of inheritance of special type of immune reaction to “hostile“ substance.
- the Reason of hereditary diseases - “breakages“, or the mutations arising in heredity carriers - chromosomes and genes.
- of the Chromosome are created by molecules DNA, and each molecule is divided into separate sites - genes. Connecting, gametes give rise to a new organism. That is a half of chromosomes in an organism - fatherly, a half - maternal.
- Gene diseases arise from - for damages of one or several genes. the Chromosomal diseases caused by change of number of chromosomes are not descended by
Influence of the environment
Scientists incline that predisposition to all diseases, only in different degree is inherent in all people. Diseases with hereditary predisposition differ in it from gene diseases when people with a pathological set of genes are always sick, and with a set within norm - are always healthy.One more difference of diseases with hereditary predisposition from gene that the probability of their development directly depends on factors of external environment the poet such diseases still call
multiple-factor. Risk factors are known for each illness, and for the majority of diseases they play a crucial role.
So, general distribution of short-sightedness coincided with emergence of television, a craze computer games and the increasing school loading. One more striking example - obesity: whatever corpulent were relatives, the person will not be able to recover if he keeps to a low-calorie diet. The fact that the person who is in adverse conditions who in a sort had no sick relatives can get sick is explained by strong influence of external factors, and that at whom hereditary predisposition is available remains healthy if minimized risk factors. Therefore some scientists speak about inheritance not of predisposition to a disease, and more likely resistance of an organism to adverse external effects.Dependence of diseases with hereditary predisposition from external factors confirms to
also that prevalence of the majority of them increased for the last 50 - 60 years. During this time genes just could not undergo essential changes, but habits and a way of life of people strongly changed. Therefore it is warm - vascular diseases, obesity, diabetes develop at the people who are not predisposed to them, but abusing greasy food, leading an inactive life. The proof of influence of external factors on development of diseases with hereditary predisposition is also that the risk increases with age: among people 50 years are more senior more than a third suffer from one or several chronic diseases. > Prichinno`s
- investigative communication
of the Disease with hereditary predisposition are divided p into three groups. The most extensive part - the diseases connected with a metabolic disorder which is aggravated with an unhealthy way of life: atherosclerosis, hypertension, coronary heart disease, obesity, diabetes. At early age these diseases meet approximately in 5 - 10% of cases. At the majority they develop after 50 years.the Down syndrome
At women till 25 years on 2000 babies is born
the Second group - mental diseases, the most widespread of which - schizophrenia, epilepsy, it is maniacal - depressive syndromes and Alzheimer`s disease. In this group of diseases the role of heredity is essential. And for Alzheimer`s disease it is estimated at 80%. External factors influence age at which the disease develops. After 70 years a third of elderly people has Alzheimer`s disease. Physicians say that the life expectancy is higher, the probability to ache is higher.
the Third group - diseases, the most dependent on environment. So, predisposition to oncological diseases doctors estimate everything at the same 10%. In this case close relatives are ill the same form of cancer, and there is it till 50 years. Other cases are caused by the mutations in cells of the person happening over all his life and caused by adverse factors. By advanced age the amount of defects collects, and the illness develops. Unfortunately, cancer benign does not happen.Same
treats also an allergy. Earlier children had a diathesis which just signaled about predisposition to an allergy. But it was not realized in an illness, on the contrary, children “outgrew“ it. Now the situation changed. The allergy arises at adult age at people whose parents never had this illness. The matter is that there were thousands of substances unknown to immune system of the person. People with predisposition to an allergy at a meeting with them react the first. Now about 40% of the population living in the developed countries have an allergy. Scientists consider that in the next generation of this misfortune about 70% of the population will be subject.from
After 70 years Alzheimer`s disease a third of elderly people suffers. Here physicians estimate a heredity role at 80%. And the life expectancy is higher, the probability to ache is higher.
the Special case - alcoholism. A factor of development of alcoholic dependence is the low sensitivity to alcohol which is descended. And also neurochemical frustration which arise at children of alcoholics during pre-natal development. This predisposition is realized, some scientists, in many respects from - for high emotional and mental loadings which life of the modern person is full consider. By means of alcohol and other psychotropic substances people try to reduce stress. Many scientists are sure that the crucial role in development of alcoholism is played by household habits. However, cases when in a family of alcoholics the children who are not transferring alcohol to spirit grow up are known to all, and natives of families where alcohol it was tabooed, begin to abuse alcohol over time.Program defects tell
About obvious hereditary predisposition to this or that disease only when the disease arises at young age, hard proceeds and when this disease in so severe form relatives have. Only in this case there is a risk of inheritance for future children in a family. But, according to the experts, it is at most 10%. And even they are not fatal. At observance correct, a healthy lifestyle it is possible to correct significantly hereditary burden and if not to avoid “family“ diseases at all then to have them benign.
Quite another matter when “breakages“ are recorded, or the mutations arising in heredity carriers - chromosomes and genes. Mutations arise constantly, but in each cage there is “workshop“ on restoration of DNA. Sometimes “workshop“ does not cope with amount of works, and defects remain. However the nature took care of safety of the person as species. By estimates of scientists, more than 60% of pregnancies are not born from - for chromosomal, is more rare than gene anomalies.Keep in mind
are developed genetic tests for definition of risk of development of a hypertension, coronary heart disease, a myocardial infarction, diabetes, venous thromboses, bronchial asthma, mental diseases and others Now.
Occur at newborns approximately in 2,5 cases on 1000 been born. The reason - abnormal number of chromosomes in cages or violation of their structure. The most widespread defect - a trisomiya when instead of the put 46 chromosomes in a cage there are 47. Most of all “trisomik“ are born with a Down syndrome - one case on 600 newborns.
concerning whether there is a genetic predisposition to chromosomal violations, scientists of a consensus have no. But it is known that the excess chromosome more often happens maternal. Therefore emergence of chromosomal anomalies strongly depends on age of mother: at women till 25 years on 2000 babies only one is born with a Down syndrome, and if he was born at the woman till 35 years, the probability of repetition of such anomaly at future children is estimated at 1%. At women 35 years are more senior the ratio makes 1:85 therefore doctors carry them to risk group.Who can appear
When planning pregnancy is strongly recommended to address in the physician - genetic consultation:
- to couples which relatives have hereditary diseases or in the presence of suspicions on such diseases.
- to couples at which the child with malformations was already born.
- to couples consisting in closely related marriage.
- to couples in which the partner is more senior than 35 years.
- to couples in which the woman had a spontaneous abortion.
them is caused by violation of synthesis of some protein that, in turn, occurs from - for damages of one or several genes. On average gene diseases occur at 0,1 - 1,2% of the population. Two diseases are most often diagnosed for newborns. It is a fenilketonuriya (FKU) and mukovistsidoz.to Fenilketonuriya`s
it happens from - for violations of synthesis of one of amino acids that involves intellectual backwardness. Frequency of distribution of FKU in the European countries fluctuates from 1:5000 to 1:15000. Therefore in all developed countries including in Russia, already in maternity hospital check all for FKU newborn.
Mukovistsidoz (cystous fibrosis) - the most widespread among the known hereditary diseases. Everyone 20 - y the inhabitant of the planet is the carrier of a defective gene. The birth of the sick child is possible for 25% if both parents are carriers of genetic defect. In Russia 15000 patients mukovistsidozy are recorded, i.e. frequency makes about 1:10000. Since recent time of newborns check also for this disease. With a high share of probability to estimate risk of developing of a disease at posterity the analysis of a family tree and DNA - diagnostics allows.
|Table of inheritance|
|of the Illness||Parents||Children (risk, %)|
|Short-sightedness|| Are healthy |
| of 8% |
of 30% to 18 years
of 50% to 18 years
|Is warm - vascular diseasesAre healthy|| till 50 years |
One Varicosity ached till 50 years
| of 30% of moderate severity |
of 50% in an average or severe form
| Are healthy till 50 years is sick till 50 years |
| of 30% of moderate severity |
| Are healthy |
One is sick with
| of 5% |
|Bronchial asthma, allergy|| Are healthy with |
One it is sick with
Both Evgeny Ginter , the academician of the Russian Academy of Medical Science, the Dr.Sci.Biol., professor, the deputy director for scientific work of GU Mediko - the genetic Russian Academy of Medical Science scientific center are sick
| of 7% |
the Comment of the expert
some optimism concerning diagnostics and treatment of hereditary diseases. Now in Russia programs of prenatal diagnostics work. They include first of all ultrasonography which is carried out three times during pregnancy. Research allows to reveal up to 60% of congenital defects including chromosomal diseases. In particular, for a Down syndrome there are now very powerful markers which almost for 100% indicate a disease. To all women biochemical blood tests are conducted: content of some proteins which are fruit waste product demonstrates that with a fruit not everything is safe.
Invasive methods at which different fabrics of a fruit are investigated allow to reveal all chromosomal diseases. Such researches are conducted free of charge to the women entering into risk group. If diagnose a chromosomal disease for a fruit, the question of pregnancy interruption is raised. The woman makes the decision independently. The European experience demonstrates that thanks to prenatal diagnostics the birth of children with a Down syndrome was reduced many times.
available. This method allows to reveal the mutant genes causing a concrete illness that is actual for those whose relatives have a hereditary disease. It is recommended to pass such test also to couples consisting in closely related marriage. Research will show whether the person is the carrier of a mutant gene and what probability of transfer to his child. Helps to estimate risk of emergence of posterity with hereditary diseases also a family tree. Happens, DNA - diagnostics people who in a sort had no hereditary diseases want to pass. In some measure such desire is considered as “whim“. But we can look at about one and a half hundred genes in which mutations meet most often. Such research will cost several tens of thousands of rubles.
newborns Have a progress and in detection of gene hereditary diseases. To all babies in maternity hospital screening on four hereditary diseases is without fail carried out: fenilketonuriya, mukovistsidoz, adrenogenital syndrome and galactosemia. All these diseases, except for a galactosemia, meet quite often. But, the main thing, they give in to correction that, actually, and justifies carrying out screening.
In general, about three tens hereditary diseases of a metabolism will respond to treatment!“