Methods of research of human genetics.
At present, genetics is very relevant inscientific fields for research. The impetus for its development was the well-known teaching of Charles Darwin on the discreteness of heredity, natural selection and mutational changes due to transmission of the carrier genotype. Beginning its development at the beginning of the last century, genetics as a science has reached a large scale, while methods of researching human genetics at the moment are one of the main directions of studying both human nature and wildlife in general.
Let's consider the basic methods of genetics research, known at the present time.
Genealogical methods of human genetics research analysis and definitiontypical gene structures when inheriting in pedigrees. The obtained results and information are used to prevent, prevent and identify the probability of occurrence of the studied trait in the offspring - hereditary diseases. The type of inheritance can be autosomal (the manifestation of the trait is possible with equal probability in persons of both sexes) and linked to the chromosomal sexual range of the carrier.
The autosomal method, in its turn, is divided intoautosomal dominant inheritance (the dominant allele can be realized both in the homozygous and in the heterozygous state) and autosomal recessive inheritance (the recessive allele can only be realized in the homozygous state). At this type of inheritance, the disease manifests itself after several generations.
Sex-linked heredityis characterized by localization of the corresponding gene in homologous and nonhomologous sections of the Y or X chromosomes. According to the genotype background, which is localized in sex chromosomes, a hetero- or homozygous woman is identified, but men who have only one X-chromosome number can only be hemizygous. For example, a heterozygous woman can transmit the disease by inheritance to both her son and her daughters.
Biochemical method of genetics research is conditioned by the study of hereditarydiseases transmitted as a result of gene mutations. Such methods of investigation of human genetics reveal hereditary metabolic defects by determining the structures of protein, enzymes, carbohydrates and other metabolic products that remain in the extracellular fluid of the body (blood, sweat, urine, saliva, etc.).
Twin methods of human genetics research determine the hereditary conditionalityinvestigated signs of the disease. Odnoyaytsovye twins (a full-fledged organism develops from two or more fragmented parts of the zygote at an early stage of its development) have an identical genotype, which allows to identify differences as a result of external influence of the environment on the human phenotype. Broken twin (fertilization of two or more ova) have a genotype of related people, which makes it possible to assess the environmental and hereditary factors of the development of the genotype background of a person.
Cytogenetic method of genetics research used in studying the morphology of chromosomes andthe normality of the karyotype, which makes it possible to diagnose hereditary diseases at the chromosome level when detecting genomic and chromosomal mutations, as well as to investigate the mutagenic effect of chemicals, pesticides, drugs, etc. This technique is widely used in the analysis and subsequent detection of hereditary anomalies of the body before the birth of the child. Prenatal diagnosis of the amniotic fluid makes the diagnosis already in the first trimester of pregnancy, which makes it possible to make a decision about the termination of pregnancy.