[A genetic analysis of endocrine diseases of the thyroid and pancreas].

The genetic determination of insulin-dependent (IDDM) and non-insulin-dependent (NIDDM) diabetes mellitus and thyroid gland diseases (TGD) was carried out using clinical-genealogical data on 229 patients with IDDM, 275 patient with NIDDM, 247 patients with TGD and their relatives. Results of component decomposition showed the role of genetic factors in the determination of these diseases and the existence of interloci interaction in genetic control of IDDM and NIDDM. The genetic independence of these diseases and genetic homogeneity of NIDDM were revealed using models of Ch.

[An analysis of the linkage of hypertrophic cardiomyopathy and the delta locus of the T-cell receptor (TCRD) chain in the family of P].

Aim: To estimate probability of location of the gene determining family hypertrophic cardiomyopathy (HCMP) in family P. on the 14th chromosome in segment 14q11 using parametric method "lod score".

Materials And Methods: The family of proband P.

[Analysis of linkage of HLA antigens and rheumatoid arthritis].

Based on consistent associations of rheumatoid arthritis (RA) with some HLA antigens several authors hypothesized the existence of a gene of susceptibility to RA, linked closely with the HLA loci and in disequilibrium with associated alleles. Data on six pedigrees (four of these involved three generations) with recurrent diseases (in total, 45 individuals, 13 of whom were affected with RA) were used in the linkage analysis. The data on allelic typing of HLA-A and -B loci were combined to form a "superlocus" that enabled more accurate determination of an individual genotype for the marker.

[Features of linkage analysis of a "key" gene of a disease].

Peculiarities of linkage analysis are considered for the case of disease inheritance deviation from a simple Mendelian pattern, including incomplete and different for two sexes penetrance of genotypes and possible presence of phenocopies. With regard for the peculiarities and within the frames of the likelihood ratio method, a software package was developed and tested on IBM PC-compatible computers. The package allows one to obtain the highest lod score for small pedigrees and the corresponding estimates of recombination frequency in men and women.

[Genetic determination of rheumatoid arthritis. Distribution of certain Mendelian markers in the light of correspondence of the disease heritability to the model of single autosomal two-allele locus with incomplete penetrance].

The study on the nature of distribution of certain mendelian markers aimed at specifying their role in determination of rheumatoid arthritis disease was carried out, based on the material from the Family Data Bank of the Department of Epidemiology and Genetics of the rheumatic diseases in this institute comprising data on 200 families of patients with definite rheumatoid arthritis (RA). Antigens of HLA-system (the loci A, B, DR), ABO blood groups, Rh, MN and P, phenotypes of acid erythrocyte phosphatase and the types of haptoglobin were studied. Based on the data from this and the previous studies, it is established that the steadiest deviations of the RA patients groups from the general population concerned the frequency of HLA A11, B12, B27 and DR4, blood group P and phenotypes of the acid erythrocyte phosphatase.

[Genetic determination of rheumatoid arthritis].

The study on the nature of genetic determination of the definite rheumatoid arthritis (RA) and its forms was carried out, based on the material comprising clinical data on 189 probands and their 1st and 2nd degree relatives (713 subjects) which is contained in the computer Family Data Bank at the Department of Epidemiology and Genetics of this institute. The heritability coefficient "in narrow sense" (80%) obtained within the framework of the multifactorial threshold model confirmed once more important role of genetic factors in the appearance of the disease. The study of genetic heterogeneity within the framework of the Ch.

[Defining parameters of the model of single autosomal two-allele locus with incomplete penetrance differing in the two sexes].

A variant of the model of single autosomal two-allele locus with incomplete and different for both sexes penetrance is under consideration. The variant may be used for revealing the effect of the major gene for determination of multifactorial disease encountered with different frequencies in men and women. Some approaches to obtaining the values of 7 parameters of the model under consideration are regarded on the basis of usually available data on probands' relatives.

[The role of hereditary factors in the development of psoriatic arthritis and the nature of its interrelations with psoriasis].

Altogether 83 families of probands with psoriatic arthritis and the same number of families of probands with common skin psoriasis were investigated in order to study the role of hereditary factors in the development of psoriatic arthritis and the type of its interrelationship with psoriasis. Obvious accumulation of repeated cases of this disease was observed among the probands' relatives. Genetic analysis made it possible to reject the monogenic type of inheritance of psoriatic arthritis and to prove the multifactorial nature of its inheritance confirmed in 68%.

[Genetic analysis of antithymocyte activity in schizophrenia].

Immunologic changes in schizophrenic psychoses were examined by different methods of genetic analysis. The cytotoxic test and the method of fluorescent antibodies showed an increase in the antithymocytic activity (ATA) of the blood serum. A high index of the coefficient of a genetic correlation between elevated blood levels of ATA and the genetic component of liability to the disease indicates that genetic factors partially involved in the general structure of hereditary predisposition to schizophrenic psychoses participate in the determination of interindividual differences with regard to blood ATA levels.

[Anti-thymocyte antibodies in schizophrenia: clinico-immunologic and genetic correlations].

The blood levels of anti-thymocytic IgG, IgM and IgA were studied in schizophrenics, their relatives and normal donors. The schizophrenic patients and their relatives had significantly elevated levels of IgG and IgM. The increased level of IgG in schizophrenic patients may be considered as a reflection of the pathological process or, perhaps, as a response to disease exacerbation.

[Determination of the parameters of the single 2-allele autosomal locus model with incomplete penetrance].

A method for estimating the parameters of the single autosomal two-allele locus model with incomplete penetrance (the gene frequency and penetrances of the three genotypes) is presented. The method requires the presence of (1) the population frequency of the trait; (2) any set of incidences in relatives of probands that would allow to obtain the estimations of additive and dominant genetic variances and (3) segregation frequencies determined by the generalized Weinberg's method. The method proposed yields the uniquel estimations of the model parameters for traits which have additive genetic variance differed from zero.

[Equations for segregation frequencies determined by Weinberg's generalized method in a model of a single autosomal 2-allelic locus with incomplete penetrance].

Equations are proposed for segregation frequencies determined by generalized Weinberg's method (SFw). The equations give an expression for SFw in terms of basic parameters of a single autosomal two-allele locus model with incomplete penetrance (SAL-2 model), namely, in terms of the frequency of one of the alleles and the penetrances of three genotypes (p, II2, II1, II0). The equations proposed are intended to be included into the system of equations to find the basic parameters of the SAL-2 model.

[Use of the integral parameter of dermatoglyphic differences for determining the type of zygosity of twins].

A method is described increasing the reliability of twin zygosity diagnosis in cases when the possibility of using a large number of mendelian markers is restricted. The method is based on the determination of generalized index of dermatoglyphic differences between members of twin pair for 18 characteris of finger and palm dermatoglyphics and on principles of multivariate genetic analysis, which is worked out to determine the degree of heritability of multifactorial character and to study the structure of hereditary predisposition to multifactorial diseases. The efficiency of the method with respect to determinating the type of twin zygosity is approximately equivalent to the efficiency of using 5--6 mendelian marker systems.

[Inheritance of human finger and palm dermatoglyphic characteristics].

The degree of genetic determination of 25 quantitative dermatoglyphic characteristics has been studied on family: twin material: 45 pairs of MZ and 75 single-sex DZ twins; and 53 single-sex "parent-child" pairs. Approximating formulae were used to estimate main components of phenotypic variance due to additive interaction of genetic factors, to non-linear effects (intralocus dominance) and to the effect of total-familiar and random environmental factors. All the finger dermatoglyphic characteristics studied had a high degree of genetic determination (G greater than 0,80), and for most of them the contribution into the large variance of intralocus dominance effects was comparable with that of additive gene interaction, included in the determination of these characters.