Linkage analysis of a model quantitative trait in humans: finger ridge count shows significant multivariate linkage to 5q14.1

The finger ridge count (a measure of pattern size) is one of the most heritable complex traits studied in humans and has been considered a model human polygenic trait in quantitative genetic analysis. Here, we report the results of the first genome-wide linkage scan for finger ridge count in a sample of 2,114 offspring from 922 nuclear families. Both univariate linkage to the absolute ridge count (a sum of all the ridge counts on all ten fingers), and multivariate linkage analyses of the counts on individual fingers, were conducted. The multivariate analyses yielded significant linkage to 5q14.1 (Logarithm of odds [LOD] = 3.34, pointwise-empirical p-value = 0.00025) that was predominantly driven by linkage to the ring, index, and middle fingers. The strongest univariate linkage was to 1q42.2 (LOD = 2.04, point-wise p-value = 0.002, genome-wide p-value = 0.29). In summary, the combination of univariate and multivariate results was more informative than simple univariate analyses alone. Patterns of quantitative trait loci factor loadings consistent with developmental fields were observed, and the simple pleiotropic model underlying the absolute ridge count was not sufficient to characterize the interrelationships between the ridge counts of individual fingers.     

Fixed and random effects in the variation of the finger ridge count: a study of fragile-X families.

A maximum-likelihood scoring technique for analysis of pedigree data allows for the concurrent estimation of random and of fixed effects in a quantitative trait. We included both types of effects in genetic models, to study the sources of variation in finger ridge count in 54 large families affected with the fragile-X disorder. The fixed effects were represented by fragile X and sex, and the random effects by environmental and genetic variance. We found a significant effect of fragile X in the mean of the finger ridge count on the thumb (finger 1) and index finger (finger 2), which had the lowest heritability and a negligible nonadditive component of genetic variance. This was in contrast with ridge counts on fingers 3 and 4, which showed little fragile-X effect, but high heritability and a significant nonadditive component. A contrast in genetic properties for ridge counts on fingers 1 and 2, compared with these counts on the remaining three fingers, may be relevant to increased selection pressures on functions of the thumb and of the index finger in evolution of modern man. We have also demonstrated an important effect of fragile X in increasing the additive variance in covariance, especially between male pairs. These findings suggest that the effect of the fragile-X genotype in finger ridge count is additive and superimposed on the normal hereditary variations in this trait.     

A family study of dermatoglyphic traits in India: a search for major gene effects on palmar pattern ridge counts

Palmar pattern ridge counts were subjected to segregation analysis in an attempt to identify possible major gene effects on these dermatoglyphic traits. The phenotypes considered were total palmar pattern ridge count, and ridge counts for the right interdigital III and IV and left interdigital IV individual palmar areas (sample sizes were too small for the other palmar areas). Evidence of familial resemblance was found for all of the phenotypes studied, and initial evidence for a major effect was found for all but the right palm interdigital III ridge count. However, this initial evidence could be attributed to nongenetic effects in each case, including skewness in the trait distribution. Tests for agreement with Mendelian transmission frequencies were found to be very useful in discriminating between a non-Mendelian major effect and a major gene. We concluded against a major gene effect for any of these traits, and multifactorial inheritance remains a plausible alternative explanation for the familial resemblance.     

Genetic Significance of the relationship between absolute total finger ridge count and its variability

In order to test the hypothesis of a major gene effect on absolute total finger ridge count (ATFRC), the nature of relationship between mean ATFRC and its variability was evaluated in a series of 47 population samples from India. Regression analysis showed that both the standard deviation and the coefficient of variation are significantly related to mean ATFRC, and about 35% of the variation in ATFRC is explained by the dependent variable coefficent of variation. These results support the hypothesis of a major gene effect on the trait ATFRC.     

Digital dermatoglyphics of 107 Bengalis.

I analyzed the finger prints of 59 male and 48 female unrelated Bengalis in a rehabilitation camp of Dacca, Bangladesh. The most common pattern type in the Bengalis was the ulnar loop (53%), then whorls (40%); arches (5%) and radial loops (2%) were the least common. Radial loops occurred most frequently on the index fingers. I have shown the arch/whorl, whorl/loop, and pattern intensity indices, and I have presented ridge counts by individual digits and by total digital ridge count. Digital dermatoglyphics in the male Bangladeshis were similar to previous findings in male Brahmins of Bengal. However, there were more whorls and arches, fewer loops, and a higher mean total digital ridge count in the female Bangladeshis than in female Brahmins.     

Characterization of an inbred mouse exhibiting low responsiveness to phosphorylcholine. Antibodies from low-responder mice suggest gene conversion events within the S107VH gene family

An inbred strain was derived from feral mice that respond poorly to phosphorylcholine (PC) but responded normally to a variety of other Ag. Low responsiveness is inherited as a single recessive autosomal trait, characterized by very low levels of both PC-binding serum antibody and PC-specific B cells. Analyses of PC-reactive clonotypes generated in limiting dilution culture, as well as analyses of PC-specific hybridomas, indicate that this strain expresses L and H chain V regions not previously associated with high affinity murine PC-binding antibodies. Further, sequence analyses suggest gene conversion events occurred within the S107VH gene family among the progenitors of this strain subsequent to their divergence from those of most common laboratory strains.     

The relationship between total ridge count and pattern intensity index of digital dermatoglyphics

A mathematical relationship between total ridge count (TRC) and pattern intensity index (PII) is explored using data from a sample of 180 males and 213 females of Negroid origin from southwestern Haiti, West Indies. Linear regression of total ridge count on pattern intensity index gave good fit to data in males. In females the linear and quadratic regression models were less satisfactory probably due to the considerable overlap of ridge count distribution between loops and whorls. Two other measures which compare better than total ridge count are absolute ridge count and weighted total ridge count. Predictions of TRC from PII on the basis of regression estimates from Haitian data gave satisfactory results for Negroid and some Caucasoid populations but less satisfactory results for Mongoloid groups suggesting that the relationship might be different in different ethnic groups.     

Three palmar dermatoglyphic traits and their asymmetry in Bulgarian right-, mixed- and left-handers

Summary: In a sample, comprising 264 right-, 246 mixed- and 360 left-handers (RH, MH and LH, correspondingly), the atd-angle, the a-b ridge count and the hypothenar radial arch were investigated, the asymmetry of both quantitative traits differentiated into directional (DA) and fluctuating (FA) one. Except for the FA of the a-b ridge count in females, which decreased significantly from RH to LH, the trends observed in the relations between the investigated dermatoglyphic values and handedness were not significant. In both quantitative traits the most important finding was the categorical left-palm excess over the right palm, since it was significantly related to sex and handedness, being much more expressed in females than in males and in the non-right-handers than in the right-handers. The hypothenar radial arch, along with its considerably higher frequency in females than in males and on the right palm than on the left, as well as its rarity combined with a very high symmetry, displayed another interesting peculiarity. The pattern was 3.9-fold more frequent in the MH and 3.4-fold more frequent in the LH as compared to RH. As witnessed by the odds ratio, if a given palm belongs to a non-right-hander, the probability that it bears a hypothenar radial arch is nearly 4-fold higher than if it were a palm of a right-hander. Arguments are adduced that left-handedness, although not a pathological character is, to say the least, a modified condition and that, similarly, the hypothenar radial arch is a subnormal dermatoglyphic finding. If such is the case, their relationship found by the present study is not surprising, although its causal background still remains unclear.     

Fingerprint pattern factors

Factor analysis was employed using the ulnar ridge count, radial ridge count, ridge count (the larger of the radial or ulnar count as generally used for calculating total ridge count), and pattern type for each finger in 720 twins. Pattern type and ulnar count displayed parallel factor loadings while loadings for radial and ridge count also paralleled each other. This relationship did not hold for the index finger, indicating the importance of pattern direction and greater pattern diversity for this digit. Total ridge count was most closely associated with a factor of ring and little finger radial and ridge count and only secondarily with an index finger factor. When radial and ulnar counts were deleted to make comparisons with earlier studies, the result was factors having groupings of variables identical with previous reports. It appears that factor analysis results in consistent extraction of identical or very similar factors from different populations, and the use of radial and ulnar counts adds more information than when only the larger of the two counts is considered.     

Variations on dermal ridges in nine population groups of maharashtra,india. III. Asymmetry and interdigital diversity

Variations in asymmetry and interdigital diversity for the three finger-dermatoglyphic traits, total finger ridge count (TRC), absolute total finger ridge count (ARC), and finger pattern intensity index (PII) have been studied here from a sample of 646 males belonging to nine population groups from Maharashtra, India. It is seen that at such local level of population differentiation the ridge count measures TRC and ARC discriminate the population better as compared to PII. A considerable amount of variations also exist in their asymmetries and interdigital diversities and these suggest the possibility of their genetic controls. Such genetic controls might mediate both asymmetry and interdigital diversity jointly, as there seems to be positive correlation between these measures with respect to all the three finger-dermatoglyphic traits.     

Inbreeding effects on palmar dermatoglyphic characters in three endogamous social groups of West Bengal,India

The present study reports inbreeding effects on mean palmar dermatoglyphic characteristics: triradial count on palm, maximal atd angle, adt angle, td ridge count, ab ridge count, main line index (MLI) and ab ridge breadth. Samples were drawn from adult males belonging to three endogamous sections representing Hindu caste Telaga of Kharagpur (West Midnapore), Ansari Muslims of Nandigram (East Midnapore) and Sheik-Sunni Muslims of Braddhaman in West Bengal, India. Consistent trend of higher mean triradial number, adt angle, and lower mean td ridge count, ab ridge count, and ab ridge breadth was observed in inbred sections compared to their non-inbred relatives in three social groups.     

The dermatoglyphic and clinical features of the 9p trisomy and partial 9p monosomy syndromes

Summary The physical and dermatoglyphic features obtained from published reports of 128 patients with the trisomy 9p syndrome and 27 patients with the partial 9p monosomy syndrome are tabulated. This information is also provided on two new individuals with each of these chromosomal disorders. The dermal ridge patterns and palmar creases of trisomy 9p which are most helpful from a diagnostic standpoint are zygodactylous or absent palmar digital triradii, brachymesophalangy, reduced total finger ridge count, complex thenar/ID I patterns, transverse palmar ridge alignment, simian creases, distal axial triradii, and great toe and hallucal arch patterns. The characteristic features in partial 9p monosomy include dolichomesophalangy with accessory finger flexion creases, digital whorl patterns and elevated total finger ridge count, distal axial triradii, simian creases, and palmar dermal ridge dissociation.     

Sex and side differences and correlations between quantitative palmar characteristics in a sample Sardinian population

Differences between the sexes and between the sides and the correlations between four quantitative characteristics of palmar dermatoglyphics in a sample population of 809 individuals (418 males and 391 females) from the city of Cagliari, Sardinia, are tested. Males have a greater number of ridges than females, shown by a greater a-b ridge count and A-d ridge count, and a more transverse slope of the main lines, shown by a greater main line index and papillary number. The left palm shows a greater number of ridges than the right palm between the A line and the triradius d and between the triradii a and b, with a lower main line index and papillary number. The a-b ridge count has a negative correlation with the main line index and with the papillary number and a positive one with the A-d ridge count; these correlations are greater in the left palms, especially in the males.     

Tawny: a novel light coat color mutation found in a wild population of Mus musculus molossinus, a new allele at the melanocortin 1 receptor (Mc1r) locus.

We found a new coat color mutant in a population of Japanese wild mice (Mus musculus molossinus) and called the trait tawny. The tawny mutant is characterized by a light yellowish brown coat color. The tawny hair has a so-called agouti pattern, but the yellow band is greatly lengthened. There are no differences between the tawny and wildtype hairs in size and the number of melanosomes. Genetic analyses revealed that the tawny trait is an autosomal recessive and its gene is located in the distal region on Chromosome 8 between the microsatellite markers D8Mit87 and D8Mit122. An allelism test indicated the tawny mutant gene to be a new allele at the Mc1r locus and dominant to the recessive yellow (Mc1re). The proposed gene symbol for the tawny is Mc1rtaw.     

Quantitative and genetic features of epidermal ridge minutiae on the palm of twins

The total minutia count (TMC) and fork index (FI), i.e., the proportion of forks in total minutiae, were examined in palm prints of 20 pairs each of monozygotic and dizygotic Japanese twins. No bilateral difference was found in either trait. The mean of the TMC was higher in males than in females, but the FI showed no sex difference. Both traits presented relatively high intraclass correlation coefficients between monozygotic twins, and genetic control of these traits is suggested. However, no correlation was observed between these two traits. A slight correlation was observed between the TMC and the total palmar interdigital ridge count. Some methodological problems concerned with classification criteria were discussed.     

Four independent mutations in the feline fibroblast growth factor 5 gene determine the long-haired phenotype in domestic cats

To determine the genetic regulation of "hair length" in the domestic cat, a whole-genome scan was performed in a multigenerational pedigree in which the "long-haired" phenotype was segregating. The 2 markers that demonstrated the greatest linkage to the long-haired trait (log of the odds > or = 6) flanked an estimated 10-Mb region on cat chromosome B1 containing the Fibroblast Growth Factor 5 (FGF5) gene, a candidate gene implicated in regulating hair follicle growth cycle in other species. Sequence analyses of FGF5 in 26 cat breeds and 2 pedigrees of nonbreed cats revealed 4 separate mutations predicted to disrupt the biological activity of the FGF5 protein. Pedigree analyses demonstrated that different combinations of paired mutant FGF5 alleles segregated with the long-haired phenotype in an autosomal recessive manner. Association analyses of more than 380 genotyped breed and nonbreed cats were consistent with mutations in the FGF5 gene causing the long-haired phenotype in an autosomal recessive manner. In combination, these genomic approaches demonstrated that FGF5 is the major genetic determinant of hair length in the domestic cat.     

An autosomal genomic scan for loci linked to type II diabetes mellitus and body-mass index in Pima Indians.

Genetic factors influence the development of type II diabetes mellitus, but genetic loci for the most common forms of diabetes have not been identified. A genomic scan was conducted to identify loci linked to diabetes and body-mass index (BMI) in Pima Indians, a Native American population with a high prevalence of type II diabetes. Among 264 nuclear families containing 966 siblings, 516 autosomal markers with a median distance between adjacent markers of 6.4 cM were genotyped. Variance-components methods were used to test for linkage with an age-adjusted diabetes score and with BMI. In multipoint analyses, the strongest evidence for linkage with age-adjusted diabetes (LOD = 1.7) was on chromosome 11q, in the region that was also linked most strongly with BMI (LOD = 3.6). Bivariate linkage analyses strongly rejected both the null hypothesis of no linkage with either trait and the null hypothesis of no contribution of the locus to the covariation among the two traits. Sib-pair analyses suggest additional potential diabetes-susceptibility loci on chromosomes 1q and 7q.     

广西544例瑶族儿童的皮纹学观察

本文对广西544例瑶族儿童的皮纹进行了观察分析,计算出指纹类型的百分率、指纹脊线总数、a-b脊线数、主线横向指数、掌纹主线止区、指间及大小鱼际真实花样的百分率、踇趾球部花样的百分率共七项基本参数。与汉族比较,瑶族的皮纹既有自己的特点,又具有汉族的一般特性。     

Genetic linkage studies with cleft lip and palate: report of two family studies

Genetic linkage studies are reported on two families with cleft lip +/- cleft palate. For the first family (LP01) the etiology of the clefting is unknown, and the linkage analyses were done assuming both autosomal dominant and autosomal recessive inheritance. Close linkage is rejected with the Duffy blood group under the dominant model and with four loci (Duffy, Kidd, and ABO blood groups and haptoglobin) under the recessive model. The second family (LP02) is a Mexican-American family segregating the van der Woude syndrome with lip pits. The linkage analyses for this autosomal dominant trait excluded close linkage with seven genetic markers, including three on chromosome one. The maximum lod scores were 0.6 with BF (chromosome 6) and 0.4 with the P blood group, which is not yet mapped.     

Quantitative finger dermatoglyphics in a Spanish population (Tierra de Campos)

This study deals with the finger ridge counts and the distribution of their frequencies drawn from a Spanish sample consisting of 833 school-children (417 males and 416 females), which has been collected from the geographical area of Tierra de Campos. Paired t-test and Student-t-test were used to explore bimanual and sexual differences, respectively. The results showed: a bimanual asymmetry marked by significantly higher right hand ridge count for thumb and index pairs in both males and females, ridge counts of males are always higher than the corresponding values of females; the differences being significant excepting for right and left index and for left ring-finger. The frequency distribution of TFRC was slightly, but significantly, different from normality only in males, as Kolmogorov test showed. A great homogeneity between values for TFRC of males and females from Tierra de Campos and those of the available Spanish and Portuguese populations has been found, the values being high not only in the variation ranges of the Spanish and Portuguese populations, but also in the ranges reported for other European populations.