The SD is essentially a global delay of the motor and mental development of the child. This cellular division imperfection can occur in three places: in the spermatozoon, vulo or during the first division of the cell after the fertilizao. The last possibility is very rare. They is esteem that in 20% 30% of the cases, chromosome 21 extra resulted of cellular division imperfection of the spermatozoon and that in 70% 80% of the cases, the extra chromosome comes of the mother. (PUESCHEL, 1993, p54). The deficiency is known that metal it is present in the picture of the SD and that the motor delays are corrected if stimulated well since early, but this necessary work to leave the child to develop itself in spontaneous, creative and affective way. Thus, they will be ready to enter in contact with the world for ampler inclusion in the society and with a bigger possibility of success, therefore for Pueschel (1993), in a world that little respects the individual differences, the carrying child of the SD as any another one, needs to have certain ' ' game of cintura' ' a dose of security to launch itself to the social commerce, also leaving the safe parents calmest and.
In accordance with Buckley (2010), the SD will bring to the individual a cognitivo comprometimento e, eventually, physicist, however, it does not hinder the development of many affective and intellectual potentialities. In virtue of the additional genetic material in chromosome 21 extra, children with SD has corporal characteristics that a different appearance of the one of its parents, brothers or other children confers them without deficiency. As chromosome 21 extra if finds in the cells of people with SD, it exerts an influence in the formation of the body of similar form. Thus, these children present many common characteristics and if they are similar between itself.