Inheritance of quantitative dermatoglyphic traits with asymmetry and diversity in Muzeina Bedouin tribe: a small isolated and consanguineous population from South Sinai.

The genetic factors contribute significantly to the determination of dermatoglyphic traits is well established. However, the controversies in views and findings of this issue are still inconclusive. The present study is an attempt to evaluate the inheritance of quantitative dermatoglyphic traits with asymmetry (DA and FA) and diversity (Div) through sibling correlations. Data include 218 individuals from (88 families) in a small isolate, the nomadic tribe Muzeina with a high degree of consanguinity (0.09) from South Sinai. Statistical analyses include sibling correlations, cross-correlations and genetic correlation (GC)--a ratio of sibling cross-correlation between traits divided on square root of the both traits sibling correlation product. The familial correlation coefficients for quantitative dermatoglyphic traits are perhaps expected lower in such a small isolated and consanguineous population than our previous studied in Indian populations and Chuvashian populations from Russia. These results indicate a simpler genetic basis due to high degree (0.09 inbreeding coefficient) of consanguinity in Muzeina Bedouin tribe. There is no evidence of major gene involvement, although a little genetic effect obtained from familial correlations on asymmetry (DA and FA) and diversity (Div) traits through sibling correlations. The significant interaction between sexes was found, which contradicts with the other populations perhaps due to high level of consanguinity. Lower correlation coefficients than in other non-consanguineous populations for quantitative dermatoglyphic traits indicate a simpler genetic basis due to high degree of inbreeding coefficient (0.09) in Muzeina. Dermatoglyphic asymmetry and diversity traits may be due to environmental factors rather than dominance in Bedouins, although a little genetic effect was found suggests a measure of developmental instability in human (FA).

Inheritance of dermatoglyphic asymmetry and diversity traits in twins based on factor: variance decomposition analysis.

Dermatoglyphic asymmetry and diversity traits from a large number of twins (MZ and DZ) were analyzed based on principal factors to evaluate genetic effects and common familial environmental influences on twin data by the use of maximum likelihood-based Variance decomposition analysis. Sample consists of monozygotic (MZ) twins of two sexes (102 male pairs and 138 female pairs) and 120 pairs of dizygotic (DZ) female twins. All asymmetry (DA and FA) and diversity of dermatoglyphic traits were clearly separated into factors. These are perfectly corroborated with the earlier studies in different ethnic populations, which indicate a common biological validity perhaps exists of the underlying component structures of dermatoglyphic characters. Our heritability result in twins clearly showed that DA_F2 is inherited mostly in dominant type (28.0%) and FA_F1 is additive (60.7%), but no significant difference in sexes was observed for these factors. Inheritance is also very prominent in diversity Factor 1, which is exactly corroborated with our previous findings. The present results are similar with the earlier results of finger ridge count diversity in twin data, which suggested that finger ridge count diversity is under genetic control.

Inheritance of dermatoglyphic asymmetry in 500 Indian pedigrees: complex segregation analysis.

The major aim of this study is to determine the mode of inheritance of asymmetry of quantitative dermatoglyphic traits based on principal factors through the application of complex segregation (genetic model fitting) analyses on a large ethnically homogeneous sample of 500 Indian pedigrees (2435 individuals) of two generations. By segregation analysis of the traits- PC1_FA both Mendelian and Environmental models were rejected (< 0.001) with the General model, i.e. that despite presence of significant inheritance (rejection of Environmental model), the nature of inheritance is more complex, than Mendelian one. Although a little genetic effect was observed due to familial correlations on asymmetry traits, no evidence was found of major gene contribution to be involved, but this does not contradict the notion postulated by several earlier authors that asymmetry (fluctuating) provides a measure of developmental instability in human.

Inheritance of dermatoglyphic traits in twins: univariate and bivariate variance decomposition analysis.

Dermatoglyphic traits in a sample of twins were analyzed to estimate the resemblance between MZ and DZ twins and to evaluate the mode of inheritance by using the maximum likelihood-based Variance decomposition analysis. The additive genetic variance component was significant in both sexes for four traits--PII, AB_RC, RC_HB, and ATD_L. AB RC and RC_HB had significant sex differences in means, whereas PII and ATD_L did not. The results of the Bivariate Variance decomposition analysis revealed that PII and RC_HB have a significant correlation in both genetic and residual components. Significant correlation in the additive genetic variance between AB_RC and ATD_L was observed. The same analysis only for the females sub-sample in the three traits RBL, RBR and AB_DIS shows that the additive genetic RBR component was significant and the AB_DIS sibling component was not significant while others cannot be constrained to zero. The additive variance for AB DIS sibling component was not significant. The three components additive, sibling and residual were significantly correlated between each pair of traits revealed by the Bivariate Variance decomposition analysis.

Inheritance of 18 quantitative dermatoglyphic traits based on factors in MZ and DZ twins.

18 quantitative finger and palmar dermatoglyphic traits were analyzed with the aim of determining genetic effects and common familial environmental influences on a large (358 nuclear pedigrees) number of twins (MZ and DZ). Genetic analysis based on principal factors includes variance and bivariate variance decomposition analysis. Especially, Factor 1 (digital pattern size) is remarkable, due to its degree of universality. The results of genetic analysis revealed all three extracted factors have significant proportion of additive genetic variance (93.5% to 72.9%). The main results of bivariate variance decomposition analysis appears significant correlation in residual variance between digital pattern size factor (Factor 1) versus finger pattern intensity factor (Factor 4), and palmar main lines factor (Factor 2) verses a-b ridge count (Factor 3), but there was no significant correlation in the genetic variance of factors.

Sexual dimorphism in the Turkmenian population in two types of dermatoglyphic traits: discriminant analysis.

The aim of this study is to compare the pattern of sex differences between two different sets of dermatoglyphic traits (22 quantitative and 42 indices of diversity and asymmetry). Finger and palmar prints of Turkmenian population (547 individuals) were used for Multivariate analyses includes Cluster, Discriminant and Mantel test of matrix correlations. All variables (two groups) scattered into a number of small clusters those are markedly similar between males and females. These results were confirmed by Discriminant analysis--the two groups of variables are almost similar, the percentages of correctly classified individuals are 64.14% (22 traits) and 65.45% (42 traits); and Mantel statistics--the Z values are within the level of non-significance, very good similarities in 22 (0.95) and good similarities in 42 (0.87) traits. Sex dimorphism is similar between two categories of dermatoglyphic variables may be used for sex-discrimination in different populations.

Inheritance of dermatoglyphic diversity in 500 Indian pedigrees: complex segregation analysis.

The main goal of the present communication is to determine the mode of inheritance of dermatoglyphic diversity traits through complex segregation analyses (genetic model fittings). The data consists of a large ethnically homogeneous sample of 500 Indian pedigrees (2435 individuals) of two generations. Principal component analysis, familial correlations and segregation analysis (package MAN-5) were used. A little genetic effect obtained from familial correlations but no evidence of major gene contribution found to be involved. By segregation analysis of the traits- PC 1_ Div, Div 9 and Div 11, both Mendelian and Environmental models were rejected (<<0.001) with the General model, i.e. despite the presence of significant inheritance (rejection of Environmental model), the nature of inheritance is more complex, than Mendelian model.

Sexual dimorphism in two types of dermatoglyphic traits in the Turkmenian population of Russia: principal component analysis.

SUMMARY: Objective of this study is to explore the nature of sex differences between two different sets of dermatoglyphic traits based on principal components in the Turkmenian population. Two categories of dermatoglyphic traits--22 usually studied quantitative traits and 42 variables of diversity and asymmetry were analysed among 745 individuals (309 males and 436 females). The three principal components are very prominent in both sexes--"digital pattern size factor" indicates the degree of universality, as found in earlier studies among different ethnic populations; "intra individual diversity factor" and "bilateral asymmetry factor" are also similar with the earlier studies, which suggest the genetic factor has more influence on these variables than environmental factors. These results strongly indicate that there is a common biological validity exists of the underlying principal component structures between two different sets of dermatoglyphic characters and thus dermatoglyphic factors between two groups of variables can be used for sex-discrimination in different populations.

Sexual dimorphism in the Chuvashian population of Russia in two types of dermatoglyphic traits: principal component analysis.

With the aim of determining sexual dimorphism in the component structures among the Chuvashian population of Russia, finger and palmar dermatoglyphics of 547 individuals (293 males, 254 females) were analyzed. The sex differences in two categories of dermatoglyphic traits (22 quantitative traits and 38 asymmetry and diversity traits) are reflected differently and contradictory with other ethnic groups. However, a common feature of the factor 1 "digital pattern size factor" (finger ridge counts from the first category of traits) indicate its degree of universality when compared with other populations, which suggests that the variability of finger ridge counts is determined by the same genes that control the pattern types. The factors "intra-individual finger diversity factor", and "bi-lateral asymmetry factor" extracted from the second category of dermatoglyphic traits are also similar in both sexes. However, these components are hardly described in the literature. The nature of variation of these components (from two categories of dermatoglyphic traits) appears with a good similarity between sexes, which suggests their common biological validity of the underlying component structures of the finger and palmar dermatoglyphic characters.

Inheritance of six anthropometric traits in Vaidyas of West Bengal, India.

BACKGROUND: Anthropometric traits are important quantitative traits used by biological anthropologists. Surprisingly little is known about their pattern of inter-generational transmission, probably due to lack of use of developed statistical analysis in previous studies. AIM: The present study is an attempt to approach the problem of the inheritance of anthropometric traits through advanced statistical applications. SUBJECTS AND METHODS: Measurements of 824 individuals from 200 families including two generations were collected from Barasat, West Bengal. The study includes age correction by regression, familial correlation, heritability estimation and segregation analyses. RESULTS: Results showed that there is strong involvement of the familial component in variation of anthropometric traits. The magnitude of heritability (h2= 57-83%) also supports their strong genetic basis. The results indicated that additive genes are not the only contributing factor; the effect of environment is considerable and that of dominant genes not negligible. Due to genetic interaction with the local environment (specific for each trait), heritabilities vary from one trait to another. Length measurements have higher heritability than breadth measurements. Segregation analysis revealed that either the additive or dominant major gene (MG) is responsible for this effect, which follows simple Mendelian transmission. Beside this, the possibility of the existence of an additional minor gene cannot be discarded. CONCLUSION: Anthropometric traits have a genetic basis but their mode of inheritance is quite complex in nature. There is evidence of major gene effect (along with polygenes) with Mendelian transmission.

Genetics of anthropometric asymmetry in an Indian endogamous population-Vaidyas.

To understand the genetics of Fluctuating Asymmetry (FA) and Directional Asymmetry (DA), the present study comprised 14 bilateral morphometric traits from 200 Vaidya families including 824 individuals (of two generations) from North 24 Parganas, West Bengal. The statistical analysis included: Regression analysis to remove the age effect, Familial correlation, Heritability estimation, Principal Component Analysis and Segregation Analysis (SA) using genetic model test. The obtained results revealed little effect of genetic factor and considerable amount of environmental influence on anthropometric asymmetry. The results support the idea postulated by several previous authors that FA provides a measure of developmental instability in man. The contribution of heredity on these asymmetric variables is not unimportant but that of the common environment is very substantial. The magnitude of heritability of DA traits is slightly higher than that of FA traits. Five principal factors were detected from these asymmetric traits (three factors are on asymmetry on length, head, and breadth; while last two factors represent the asymmetry of diameters). SA did not suggest any evidence of major gene contribution. But the involvement of minor genes or polygenes could not be discarded. As the study on SA of asymmetry in man is limited, similar other studies are needed to confirm the result of the present study.

Intergenerational trend of some dermatoglyphic traits in Vaidyas of West Bengal, India.

In order to investigate the intergenerational change of dermatoglyphics, fingerprints of 400 individuals were collected from an endogamous caste Vaidyas of Barasat, West Bengal. Results were compared with the data of an earlier sample of Banerjee collected in 35 years before on the same community of the same area. As it is generally known that dermatoglyphics is selectively neutral, thus if no other evolutionary forces play a role, we cannot expect any change of dermatoglyphic characters after several years. In the present study, non-significant change in the frequency of pattern and more or less same PII have been observed in both sexes. But significant quantitative differences were found between the two samples. These differences may not be due to the change of intra-uterine environment, rather due to the inter-observer error of these two studies and the small sample size of the earlier study. Because though same methods were used in both studies, inter-observer variation is much possible in ridge counting than pattern type determination.

Quantitative dermatoglyphics and population structure in Northwest India.

The nature and extent of dermatoglyphic variation in northwest India is examined with the help of 28 quantitative variables-20 finger ridge counts and 8 palmar pattern ridge counts-among 12 endogamous populations. These populations represent the entire spectrum of ethnic and socioeconomic variation of the region and are presently distributed in three different states-Rajasthan, Punjab, and Himachal Pradesh. Of a total sample of 1,160 adult males, about 100 from each group were considered. Multiple discriminant analysis and R-matrix analysis were used to derive population relationships and patterns of external gene flow, respectively. Published data on genetic markers were reanalyzed to make the comparative evaluation of the patterns with reference to dermatoglyphs. Both the discriminant analysis and the F(ST) from R-matrix analysis suggest highly significant discrimination among the northwestern groups, whether one uses only 20 finger ridge count variables or all 28 variables, including the 8 palmar pattern ridge counts. The 8 palmar variables add very little to the variation explained by the 20 finger ridge count variables. F(ST) values suggest that the populations of Punjab are most homogeneous and those of Himachal Pradesh most heterogeneous. However, the levels of differentiation are similar for dermatoglyphs and genetic markers. The pattern of external gene flow as inferred through R-matrix analysis is consistent with the breeding and population structure of the groups, although genetic markers portray a relatively more realistic picture. Overall, the patterns of variation observed in dermatoglyphs and genetic markers are consistent with different dimensions of population structure; whereas dermatoglyphs conform more to the geographic pattern and less to ethnic resemblance, the reverse is true in the case of genetic markers. Am. J. Hum. Biol. 12:315-326, 2000. Copyright 2000 Wiley-Liss, Inc.