Hereditary diseases – big group of the diseases of the person caused by pathological changes in the genetic device. Now more than 6 thousand syndromes with the hereditary mechanism of transfer are known, and their general frequency in population makes from 0,2 to 4%. One genetic diseases have a certain ethnic and geographical prevalence, others – meet identical frequency around the world. Studying of hereditary diseases is mainly in competence of medical genetics, however practically any medical experts can face similar pathology: pediatricians, neurologists, endocrinologists, hematologists, therapists, etc.further...
Hereditary diseases – big group of the diseases of the person caused by pathological changes in the genetic device. Now more than 6 thousand syndromes with the hereditary mechanism of transfer are known, and their general frequency in population makes from 0,2 to 4%. One genetic diseases have a certain ethnic and geographical prevalence, others – meet identical frequency around the world. Studying of hereditary diseases is mainly in competence of medical genetics, however practically any medical experts can face similar pathology: pediatricians, neurologists, endocrinologists, hematologists, therapists, etc.
Hereditary diseases should be distinguished from congenital and family pathology. Congenital diseases can be caused not only the genetic, but also adverse exogenous factors influencing the developing fruit (chemical and medicinal compounds, ionizing radiation, pre-natal infections, etc.). At the same time, not all hereditary diseases are shown right after the birth: so, for example, signs trochees of Gentington usually for the first time declare themselves aged 40 years are more senior. Distinction between hereditary and family pathology consists that the last can be connected not with genetic, and social or professional determinants.
Developing of hereditary diseases is caused by mutations - the sudden changes of genetic properties of the individual leading to emergence of signs new, not inherent in norm. If mutations mention separate chromosomes, changing their structure (due to loss, acquisition, a variation of position of certain sites) or their quantity, such diseases carry to chromosomal. The most widespread chromosomal anomalies are a Down syndrome (a trisomiya on 21 chromosomes), Edwards's syndrome (a trisomiya on the 18th chromosome), Klaynfelter's syndrome (a polisomiya on the X-chromosome at men), Shereshevsky-Turner's syndrome, a syndrome of "cat's shout", etc.
The hereditary diseases caused by mutations at the level of genes belong to gene diseases. They can be monogenic (caused by a mutation or lack of separate genes) or polygenic (the caused changes of many genes). Among monogenic diseases distinguish pathology with autosomno-prepotent type of inheritance (Marfan's syndrome, a disease of Recklinghausen, Elersa-Danlos's syndrome, imperfect osteogenesis, Albright's disease, etc.), autosomno-recessive transfer (a fenilketonuriya, a galactosemia, an ichthyosis, a progeriya) and the hereditary diseases linked to a floor (hemophilia, phosphate diabetes, muscular dystrophy of Dyushenn, Hunter's syndrome, Fabri's disease).
Polygenic diseases by the nature are multifactorial, i.e. in their emergence the combination of genetic and environmental factors matters. These diseases are often treated as a disease with hereditary predisposition. This group includes atherosclerosis, a hypertension, diabetes, stomach ulcer of a stomach and a 12-perstny gut, allergic pathology.
Hereditary diseases can be shown as directly after the child's birth, and at different stages of life. One of them have the adverse forecast and lead to early death, others – significantly do not influence duration and even quality of life. The most severe forms of hereditary pathology of a fruit cause spontaneous termination of pregnancy or are followed by a still birth.
Thanks to progress of development of medicine, about one thousand hereditary diseases can be revealed till the child's birth by means of methods of prenatal diagnostics today. The last include ultrasonic and biochemical screening of I (10-14 weeks) and II (16-20 weeks) trimesters which are carried out to one and all pregnant women. Besides, in the presence of additional indications passing of invasive procedures can be recommended: biopsies horiona, amniocentesis, kordotsentez. At reliable establishment of the fact of heavy hereditary pathology, abortion on medical indications is offered to the woman.
All newborns in the first days of the life are also surveyed on hereditary and congenital diseases of a metabolism (a fenilketonuriya, an adrenogenital syndrome, a congenital giperplaziya of adrenal glands, a galactosemia, ). Other hereditary diseases which are not distinguished to or right after the child's birth can be revealed by means of cytogenetic, molecular and genetic, biochemical methods of a research.
Unfortunately, full treatment of hereditary diseases is not possible now. Meanwhile, at some forms of genetic pathology essential extension of life and ensuring its acceptable quality can be reached. In treatment of hereditary diseases pathogenetic and symptomatic therapy is applied. Pathogenetic approach to treatment assumes performing replacement therapy (for example, fibrillation factors at hemophilia), restriction of the use of certain substrata at a fenilketonuriya, a galactosemia, a disease of "maple syrup", completion of deficiency of missing enzyme or hormone etc. Symptomatic therapy includes use of a wide range of medicines, physical therapy, rehabilitation courses (massage, LFK). Many patients with genetic pathology since the earliest childhood need the correctional developing occupations with the teacher-speech pathologist and the logopedist.
Possibilities of surgical treatment of hereditary diseases come down, mainly, to elimination of the heavy malformations interfering normal functioning of an organism (for example, corrections of congenital heart diseases, a nezarashcheniye of an upper lip and the sky, a gipospadiya, etc.). Gene therapy of hereditary diseases has more likely experimental character so far and is still far from broad application in applied medicine.
The main direction of prevention of hereditary diseases is medico-genetic consultation. Skilled doctors geneticists will hold consultation of married couple, will predict risk of emergence of posterity with hereditary pathology, will give professional help in making decision on a child-bearing.further...