Genetic disorders are diseases caused by one or more violations of the human genome, especially if they are present from birth (congenital diseases). Most genetic disorders are quite rare and affect one person among every few thousands or millions.
Genetic disorders may or may not be hereditary, ie passed from parent genes. When non-inherited genetic disorders, defects can be caused by new mutations or changes in DNA. When the defect is transmitted only by inheritance, this is still at the stage of the embryo. Diseases such as some forms of cancer can be caused by inherited genetic disease in some people, new mutations in other people, as well as environmental causes from third. When and to what extent a person with a genetic defect will actually suffer from the disease, almost always depends on environmental factors and conditions of human development. Some types of recessive gene disorders occur only under certain conditions.
Our specialists carry out genetic testing for the detection of diseases transmitted by inheritance. In the case where there is suspicion of a congenital defect which can lead to a high probability of disease in the family, our doctors are doing research on the presence of mutations in the genes responsible for the occurrence of malignant diseases. Genetic testing can prevent or allow to identify the disease at an early stage, and apply rapid therapeutic decision.
In such cases, the patient must undergo consultation of genetics, which will determine the next steps, as well as the need to perform molecular testing. Depending on the results of the consultation can also be issued recommendations for patients’ relatives to the first degree, with a definite program of observation and genetic tests, if required.
Genetic tests are also used for early diagnosis of cancer.
You can order a genetic test in our lab remotely by sending us a sample of blood or saliva. The test results are known, usually within two weeks.
Autosomal dominant disease
For the occurrence of such diseases only one mutated gene. Chance that the child unasaleduet this gene – 50%. Examples of this type of disorder Huntington’s disease, neurofibromatosis type 1, neurofibromatosis type 2, Marfan syndrome, hereditary nonpolyposis colorectal cancer, hereditary multiple exostosis, tuberous sclerosis, von Willebrand disease, acute intermittent porphyria.
Autosomal recessive disease
For the manifestation of such diseases requires that two copies of the mutation were subjected to gene. The victim is usually unaffected parents, each of which has one copy of mutating the gene. Two healthy parents carry one copy of the mutated gene and create a 25% risk of having an affected child, for each pregnancy. This disorder CoA dehydrogenase deficiency, cystic fibrosis, sickle cell anemia, Tay-Sachs disease, Niemann-Pick disease, spinal muscular atrophy, and Roberts syndrome.
Y-related disorders, which are also referred golandricheskimi disorders caused by mutations at the Y-chromosome. These diseases can be transmitted only from men to their sons. Women can not be affected because they do not have a Y-alosomami. Y-related disorders are very rare, but the most famous examples tend to cause infertility.
X-chromosomal dominant disease
X-linked dominant disease caused by mutations in genes on the X chromosome. One example of such a disorder is hypophosphatemic rickets. Men tend to suffer more severely from the disease. Some X-linked dominant disorders such as Rett syndrome, type 2 pigment incontinence and Aicardi syndrome usually result in death in men either in utero or shortly after birth. A woman with an X-chromosomal dominant disorder has a 50% risk of an affected child with each pregnancy.
X-chromosomal recessive disease
X-linked recessive conditions are also caused by mutations in genes on the X chromosome. Men are more prone to disease, and the likelihood of transmission of the disorder differs between men and women. Examples of such diseases are serious diseases Hemophilia A, Duchenne muscular dystrophy and Lesch-Nyhan syndrome, as well as common and less serious conditions such as male pattern baldness and red-green color blindness, Turner’s syndrome. Estimated prevalence of such diseases: Duchenne muscular dystrophy 1 7000, hemophilia 1 in 10 000.
This type of inheritance, also known as maternal inheritance, applies to genes in mitochondrial DNA. Because only egg transmit mitochondria to the developing embryo, only mothers can pass on mitochondrial disease to their children. An example of this type of disorder is hereditary optic neuropathy Leber.
Multifactorial and polygenic (complex) disorders
Genetic disorders can also be complex. Multifactorial and polygenic means that they are likely to be associated with the effects of multiple genes in combination with lifestyle and environmental factors. Multifactorial disorders include heart disease and diabetes. Although complex disorders often associated in families, they do not have a clear pattern of inheritance. It is difficult to determine a person’s risk of inheriting the steppe or pass the disorder to someone.
The most common hereditary diseases: Asthma. Autoimmune diseases. Multiple sclerosis. Cancer. Tsiliopatii. Cleft palate. Diabetes. Heart disease. Hypertension. Inflammatory bowel disease. Impaired intellectual development. Mood disorder. Obesity. Refraction. Infertility.