[Regulation of child development: genetic aspects].
Since antiquity numerous attempts have been made to evaluate a relative role of heredity and the environment in human development. In the last quarter of the 19th century Francis Galton formulated this problem as a dilemma of "Nature or Nurture"? Actually, human development is the fulfillment of a genetic programme inherited by an individual from his/her parents under quite definite environmental conditions. So, Galton's query is rather to be reformulated into a statement--"Nature or Nurture". The genetic programme of an individual is established during fertilization when the haploid nuclei of an egg-cell and sperm are united to form a diploid nucleus of the zygote. During subsequent proliferation and differentiation, the zygote progressively develops into an embryo, fetus, neonate and so on. Little known about genetic factors regulating human embryogenesis and fetogenesis. Some important inferences were made when it was found that many regulatory genes and gene families comprehensively investigated in Drosophila are close homologues to respective human genes. Among such genes are those coding for transcription factors presumably taking part in cascade regulation of embryogenesis. Some mutations of these genes were found to be involved in the origin of certain malformations in humans (Sonic Hedgehog, HOXD13 etc.). Within a wide spectrum of human malformation syndromes, a considerable part is comprised by chromosomal disorders, especially those related to partial aneusomies (some 2,000 forms). Clinical manifestations of such chromosomal syndromes are highly variable, which calls for application of computer-assisted devices for their classification and diagnosis. In addition to a number of well elaborated English- and French-language databases, Russian-language computer banks of cytogenetic and clinical data aimed at practical use in genetic health care, teaching, and research are already available; among them there are "SYNGEN", "CHRODYS", "CHRODYS-PHOTO" elaborated in the Research Center for Medical Genetics of the Russian Academy of Medical Sciences, Moscow.