FEATURES OF INDIVIDUAL DIFFERENCES AND SIMILARITIES IN COUPLES OF TWINS

The twin method is one of methods in the geneticist who is based on comparison of features of terms of twin couple: monozygotic and dizygotic twins. The study of the features of individual differences and similarities in couples of twins allows identifying the role of heredity and variation in humans. It helps to determine the relationship between the role of heredity and the environment in the formation of various signs, both normal and pathological. The analysis of concordance and discordance was carried out using the classical twin method. Difficulties arise with identification of a monozigotnost of twins. The recognition of monozygotic and dizygotic twins is made on the basis of similarity of genetically determined signs. The identity or the very close similarity is the proof of a monozigotnost. The obtained data can be specified during the research this method can be combined with clinical genealogical and population and statistical methods. All distinctions which are shown at the monozygotic twins having an identical genotype are bound to influence of external conditions. The concordance was determined in couples of twins by 22 signs. The similarity in couples of monozygotic twins was from 82% to 95.5%, similarity in couples of dizygotic twins – from 32 to 64%, similarity of sibs – from 18 to 27%. The twin method allows to solve not only genetic problems, but also to open the psychological maintenance of the concept "environment", feature of formation of the person depending on environmental social conditions.

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