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Biomedical subjects

D Loesch

Publications and source records attributed to D Loesch.

At least 37 records · Page 2Linked to original sources
PubMed1978

Genetical distance and dermatoglyphic characters. II. Intrapopulation distance coefficients.

This paper attempts to evaluate the dermatoglyphic (genetical) distance between two Polish population samples in relation to the intrapopulation distance coefficients estimated within each sample. All the coefficients have been based, in turn, on frequencies of fingertip, palmar and sole pattern elements, separately and for all characters combined. The results of a comparison of various combinations of dermatoglyphic characters with one another in respect of all successive values of a distance coefficient indicate that, if populations of mostly related individuals were compared, sole patterns have been the most efficient ones in differentiating between the two normal population samples. The values of inter- and intrapopulation distance coefficients obtained from samples consisting mostly of family units have been compared with those estimated in samples of non-related individuals. The limitations and difficulties in the interpretation of the values of a distance coefficient related both to the material used and statistical procedures are discussed.

Dermatoglyphics↗
PubMed1978

Genetical distance and dermatoglyphic characters. III. Dermatoglyphic distances within twin pairs, between left and right sides and between normals and 21-trisomics.

The dermatoglyphic (genetical) distance coefficients have been estimated within monozygotic and dizygotic twin pairs, between left and right sides of the same individual and between normal subjects and 21-trisomics. All the coefficients have been based, in turn, on frequencies of fingertip, palmar and sole pattern elements, separately and for all characters combined. Quantitative variables (pattern intensities) have also been used for independent evaluation of the C2H distance coefficient in monozygotic and dizygotic twins, and in 21-trisomics as compared with normal individuals. The values of a distance have then been considered in relation to the degree of genetical likeness between the compared items as well as to the relative contribution of each pattern combination to the overall value of a distance. Some limitations in the interpretation of the results, connected mainly with statistical procedures, are also discussed.

Chromosomes, Human, 21-22 and Y↗
PubMed1977

Topologically significant dermatoglyphic patterns in twins.

A total of 58 dermatoglyphic characters, consisting of topologically significant pattern elements, i.e., loops and triradii, on palms, soles and fingertips, were tested in a sample of 110 MZ and 111 like-sexed DZ twin pairs. The analysis included homolateral, heterolateral and bilateral concordance rates, the derived Hc coefficient, coefficients of the within-pair association, phi, derived chi2 intraclass correlation coefficients and heritability estimates based on variances (h2) and correlations (Hr), and the variance ratio F. A considerable difference was found in respect of "heritability" values between palmar and sole patterns, in that they are the highest for sole loops and triradii and the lowest for most palmar loops. These data are compared with the h2 values obtained from family correlations. The difficulties in the interpretation of "heritability" estimates based on the material of twins are pointed out and particular attention is drawn to a possibility of the additional bias in twin studies related to a degree of symmetry of the characters investigated.

Dermatoglyphics↗
PubMed1976

Genetical distance and dermatoglyphic characters. I. Interpopulation distance coefficients.

The distance coefficients between two relatively isolated population groups in Poland, based on various combinations of dermatoglyphic non-measurable characters were estimated. These were compared with the overall dermatoglyphic distance coefficients estimated separately for left and right, as well as with the serologic distance coefficient, based on ABO, Rh and Duffy blood groups. Dermatoglyphic distance coefficients, estimated from quantitative variables (pattern intensities) using Penrose's C2H analysis of variance method, were also introduced for a comparison. The differences in frequencies between two populations, separately for each character, were also compared with its heritability values.

ABO Blood-Group System↗
PubMed1975

Topological formulation of finger-tip patterns: comparison of complete and incomplete 21 trisomics with normal subjects.

Description of the topological formulation of finger-print patterns is given and illustrated by examples. In particular, the way of setting up a dictionary of total finger pattern types for the two hands separately and combined is explained. Samples of 302 normal individuals, 225 complete 21-trisomics and 173 incomplete 21-trisomics are analysed here using this method. The frequencies of the commonest total finger pattern types are compared in the three groups, using dictionaries, in which all the formulae have been listed. The mean values of radial and ulnar components for each pair of homologous fingers separately are also compared. The method is recommended for comparisons of populations, particularly if the use of a computer is expected; it can also be helpful in evaluating the total finger pattern type of any individual, in terms of the probability of belonging to one population or another, particularly if the total palmar and sole pattern types can be compared as well. Some limitations of the method from a statistical point of view are also discussed.

Chromosomes, Human, 21-22 and Y↗
PubMed1975

Discriminant functions and 21-trisomy mosaicism.

A sample of 173 cases of cytogentically diagnosed 21-trisomy mosaicism, 225 cases of complete 21 trisomy and 302 normal controls were used to form discriminant functions for mosaics versus normal controls, and also for complete 21 trisomics versus normal controls; for each of these discriminants optimal sets of ten dermatoglyphic characters were selected. The mean discriminants and discriminant coefficients were calculated on the basis of these characters, using Fisher's method. The relative position of mosaics in respect of the mean discriminant values, was found closer to the Down's syndrome group than to the normal controls. Consequently, reasonably, good separation of the mosaics from the normal controls has been achieved: the distance between the two mean discriminants is greater than two standard deviations. The distribution curves were then constructed of individual discriminants, calculated in a majority of cases from all the three groups. The distribution curve for mosaics has been found bimodal so that more detailed study of the individuals forming its first peak was undertaken; a possible relationship between the degree of dermatoglyphic distortion and cytogenetic findings is discussed and some limitations of both methods are indicated. The results concerning discriminant function indices are recommended for further use, particularly in genetic counselling. Their application in the studies of populations of parents of Down's syndrome cases is demonstrated in the group of 79 parents of two or more Down's cases and the group of 111 parents of one Down's case. On the basis of these data it is postulated that there may be some proportion of undetected mosaics amongst the parents of Down's cases, but larger numbers are necessary to support and further specify these preliminary results.

Dermatoglyphics↗