study of pedigree carried the man since ancient times.In the 18-19 centuries began to be used widely enough analysis of human pathology (disease).Thus, I began to form a genealogical research methods.Subsequently, the improvement occurred as a line drawing of pedigrees and line search variants of the statistical analysis of the available data.
Clinical-genealogical method - is a way to study the pedigrees, the use of which allows us to trace the distribution of disease in the family or the family when you specify the type of relationship between their members.
This version of the study is considered to be universal.Genealogical method is used to solve problems of a theoretical nature widely.In particular, the method used in the study:
- from establishing discriminatory nature of heredity;
- determining the type of inheritance of the disease or trait;
- assessment penetrance (frequency display) gene;
- analysis of the process of mapping (determining the position of a gene on a chromosome with respect to the other) and the clutch gene;
- study of the intensity of the mutation;
- deciphering the mechanisms based on which gene interactions.
In modern medicine, know quite a number of genetic abnormalities.That is why a program to study each pregnant woman six hereditary diseases.These include:
- Down's syndrome;
- congenital hypothyroidism;
- androgenitalny syndrome;
- cystic fibrosis.
genealogical method may be in some cases the only way, using which you can determine the type of inheritance of the disease in the family, to find out the nature of the disease, assess prognosis of disease, conduct a differential diagnosis with other genetic diseases.Furthermore, the use of the research option allows you to calculate the probability of sick children, as well as choose appropriate and suitable measures for prenatal diagnosis, prevention, treatment, rehabilitation and adaptation.
Genealogical method involves drawing up a family tree and its graphic representation.
During these events, information is gathered about the proband (the individual, which is engaged in the study of the expert) and his family.Generally, studies are carried out with the patient or carrier studied trait.However, the genealogical method can be used not only in medicine.
One pair parent children are called siblings (brothers and sisters).If only one parent - the half-siblings.They may be consanguineous (with a common father) or uterine (with a mother).
Usually drawing a family tree is carried out in order to study a few (or one) of the disease (symptoms).The amount of information may depend on the number of generations involved in it (ancestry).
Analysis of the data suggests the detection of a number of types of inheritance accounting features.
For example, in the autosomal dominant points of the identified feature in the pedigree (almost in every generation), boys and girls equally often.There are signs of one of the parents contributes to the appearance of it at halftime or offspring.
In compiling genealogies each generation must be positioned horizontally or on its radius.Numbering generations carried the Roman, and family members - in Arabic numerals.
If there is a family of several inherited diseases, unrelated to each other, for each pathology pedigree compiled separately.