[Medico-genetic study of isolates in Uzbekistan. IV. Clinico-biochemical diagnosis of hereditary diseases].

An exhaustive clinico-biochemical examination of the population of two kishlaks of the Samarkand Region, viz. Karakent (210 persons) and Ishan (248 persons) was carried out. The program of this examination permitted to exclude over 160 forms of hereditary pathology. A total of 45 persons affected with diseases belonging to 12 nosological forms were revealed in the course of the examination. Among the diseases observed only 5 are hereditary sensu stricto, viz. myoclonus-epilepsy, Bonevi-Ulrich's syndrome, imperfect osteogenesis, pigment choreoretinite and Down's syndrome, others belong to diseases with a pronounced hereditary predisposition. The main part of this group comprises neuro-psychic diseases, such as non-differentiated olygophreny (5.0%), epilepsy (1.3%), schizophreny; many of these cases have a familial character, particularly in Karakent. Besides the persons suffering from diseases, 20 heterozygous carriers of beta-thalassemia and 17 heterozygous carriers of G6PD-deficiency were discovered in the kishlaks examined. On the whole the frequency of the diseases revealed did not exceed the level in the general population. Despite the different degree of isolation of the kishlaks examined (Karakent is isolated on a religious basis, F = 0.0064; while Ishan is a desintagrated isolate, F = = 0.0014), no substantial differences between them in the distribution of pathological phenomena were observed. On the basis of the experience of this expedition recomendations are proposed concerning the origination and accomplishment of medico-genetic expeditions. A scheme is proposed for the performance of medico-genetic examination through several stages. The first stage in the composition of tentative maps of the distribution of hereditary diseases within a region on the basis of the information obtained from the medical personnel and from the examination of the documents of district and regional hospitals. Subsequently the primary information is specified, the regions to be examined are determined, as well as concrete tasks and the staff of the expedition. The conclusive stage is the medico-genetic examination proper, including clinical, biochemical, immunological and cytogenetic diagnoses of hereditary pathological phenomena. The place of the disposition is a village or a district hospital. More complicated laboratory studies should be performed on the basis of the institution by which the expedition is formed. The results obtained by such expeditions would be important for the investigation of the problems of genogeography, for the discovery of new forms of mutant alleles, for the investigation of the causes and the conditions of the formation of the definite populational structure, of clinical polymorphism of human hereditary diseases.