THE ROLE OF GENETICS ON DEVELOPMENT

The Role of Genetics on Development

The Role of Genetics on Development

Genetics on Development

The growth and development processes are simultaneous and interdependent phenomena. Both processes have characteristics common to all individuals of the same species, making them predictable, but differ widely between subjects, given by the individual character of the pattern of growth and development. This archetypal pattern emerges from the interaction of genetic and environmental factors, which provide, on the one hand, the potential growth and, secondly, the extent to which this potential is expressed.

Genetic information set precisely the sequence and timing in which these processes must occur, so that if any noxa acting in these periods, preventing an event will occur on time, can produce a definitive disorder of growth or development. These periods are called critical periods. The same noxa acting at another time of development may not produce this change or be reversed. The deficit of thyroid hormones in utero and the first two years of postnatal life leaves a permanent neurological damage, whereas at later ages as deficiency can cause alterations in the nervous system that are reversible to the replacement of these hormones. This situation exemplifies the interdependence on the one hand that may have development processes (a thyroid disorder alters the maturation of the CNS) and the other hand, shows the critical period of CNS development (Stern, 2000).

The genetic heritage of each gives him a pattern of growth and meticulous development, which can be modified by environmental factors. In relation to size, genetic effects are clearly exemplified by observing the growth pattern of different ethnic groups, being the most extreme example comparing the marked difference in size between individuals of Nordic origin and the Pygmies of New Guinea. Family differences are as obvious as the differences between the races. The genetic influence is clearly established, noting the similarity in size that occurs between monozygotic twins, which has a correlation of 0.94, whereas in dizygotic twins, this correlation drops to 0.5. Study of the correlation coefficients in families, suggest that growth factors derived from both parents and each of them have a theoretical influence of 50% in the size of children. Clinical and experimental genetics, show that the determination of size is polygenic, participating in both genes located on autosomes and sex chromosomes. The legacy not only influences the final height and body proportions of an individual, but ...