Perhaps half of all patients with multiple abnormalities have known, recognized syndromes. The other half represent unknown entities that need to be further delineated. The significance of syndrome delineation cannot be overestimated. As an unknown syndrome becomes delineated, its phenotypic spectrum, its natural history, and its risk of recurrence become known, allowing for better patient care and family counseling.

The process of syndrome delineation is discussed in terms of unknown genesis syndromes of the provisionally-unique and recurrent-pattern types, and known-genesis syndromes of the pedigree, chromosomal biochemical-defect, and environmentally-induced types. Several special syndrome categories are defined, including the chance syndrome, variant additive syndrome, association syndrome, exceptional chromosomal syndrome, and exceptional monogenic syndrome. Finally, a population definition of a syndrome is developed.

Allow me to start by observing that, in the word “reproduction”, the initial syllable, Re, has a remarkable importance, at least to the geneticist. In fact, when we say “reproduction”, we do not merely mean that a living being is produced, but we also mean that the production of such a living being implies the repetition of a model that is present in the species, in the population, in the family.

Moreover, the model that is reproduced is not only that of an embryo, of a fetus, of a neonate, but is also that of a child, of an adolescent, of an adult, of an old man.

Reproduction is therefore the repetition of a model that is not limited to the amphimixis, to gestation or birth, but that dominates throughout the entire cycle of life with a continuous variability, that is, through a dynamic and individualized phenogenesis. Such an extension of the concept of reproduction from the stage of conception to the standards of the successive ages, requires that a view based on immediate times be substituted with a view based on long times. This means, in other words, that a new parameter should be explicitly considered as part of the zygote's blueprint: the chronologic parameter.

The discovery of a great multiplicity of previously unknown facts and principles has served to develop the field of blood grouping into an important complex science. The formidable task of mastering the now highly complex field of blood grouping has been facilitated by the avallability of a comprehensive text on almost all aspects of the subject, which is now in its sixth edition. This invaluable source book is widely used by advanced workers in the field as well as by beginners, and is treated as the bible on the subject to the exclusion of all other texts. However, the so-called bible has serious scientific faults in that important basic principies are ignored, and certain important basic facts are distorted or misrepresented. Fortunately, other texts are available which are free of these faults, and the use of a single book as the sole source of knowledge concerning the subject has by implication given rise to the myth that the book in question is infallible and may be used alone to the exclusion of all other sources of information. The purpose of the present review has been, not to detract from the well recognized merits of the important “blood group bible” but to point out its limitations, and to point out the existence of other sources which, while not as comprehensive, are free of mythology. If this review serves to remind the readers to consult other sources in addition to the blood group bible, it will have served its purpose, and this may lead to further advances in the field of blood grouping as well as help do away with the thriving field of blood group mythology.

This paper presents a historical view of the development of the concept of ectodermal dysplasia, analyses five current “definitions” of the group, and classifies 52-57 ectodermal dysplasias into subgroups on the basis of criteria developed by the Author.

A chronogenetic analysis of caries has been carried out in a sample of 100 twin pairs (27 MZ, 64 DZ, 9 UZ) aged 3-8 years, taking into account the number of decayed teeth and the intensity and severity of caries. Heritability estimates, calculated for each of the various parameters considered, support the hypothesis of a genetic control of the time of onset of caries.

A simple additive model of genes plus environment, based on intrapair similarities observed in 35 MZ and 35 like-sexed DZ twin pairs, was used to estimate the relative contribution of genetically controlled phenotypic variance in psychomotor individuality. Subjects practiced 50 trials on a pursuit rotor apparatus under a 20-sec/20-sec, work-rest schedule with a 30 min rest pause allowed between trials 30 and 31. Analyses of the data disclosed that a greater proportion of genetic factors, as opposed to nongenetic factors, appears to account for existing individual differences in motor performance among individuals subject to similar environmental conditions. The strength of this genetic control, however, systematically diminished throughout the course of practice obeying a monotonie trend over trials.

To search for evidence of genetic variation among the aminoacyl-tRNA synthetases, a semi-automated assay procedure employing a Technicon Auto Analyzer was used to measure erythrocyte arginine-tRNA synthetase activity in samples obtained from normal human twins of various ages. Variation in enzyme activity within the older DZ twins was five times that of the MZ twins suggesting the existence of genetically determined variation in enzyme activity. Higher enzyme activity was observed in newborn DZ unlike-sexed twins than in like-sexed twins of either zygosity. Possible explanations for this observation are discussed.

Aiming at determining the influence of some genetic factors on growth and development, a longitudinal study of 180 children (90 M and 90 F) from the city of Lublin was carried out, with periodical medical examinations and anthropometric measurements from birth to 7 years of age. The parents of each child were also examined.

The correlation coefficients between parents and children show that, as regards height, the greatest similarity occurs between mothers and daughters, and a lesser one between fathers and sons. As regards weight, sons are more similar to fathers than daughters to mothers.

The relationship between the growth and development of children and the mating type of parents, parental age, and birth order, was also investigated. In negative assortative mating, the children are taller than the children of middle-height parents from positive assortative mating couples. Children (especially daughters) of tall mothers and short fathers grow taller than children of tall fathers and short mothers.

Finally, the dependence of growth on parental age and birth order was analysed and the conclusions reached were quite interesting.

A series of house-to-house surveys in Central Brazil revealed 32 cases of reduction deformities of the limbs (brachydactyly, synbrachydactyly, ectrodactyly, amely, adactyly, achiry, apody, etc.) among 58,761 births (0.54 per thousand, being 0.66 per thousand among Whites and 0.43 per thousand among Mulattoes and Negroes). No sibship was found with two or more equally affected singleton members. One case of concordance among twins is referred. There were no parity, inbreeding, race and sex effects. Both hands and both feet were also equally affected. Precocious mortality and twinning were significantly higher among affected individuals. The presence of cleft lip and palate in one of our index patients may also reflect an etiological relationship. Among the sibs, the total incidence of congenital malformations was similar to that generally accepted for general populations.

In the years 1966-1976, 50 pairs of Warsaw twins (27 MZ and 23 DZ) were subjected to longitudinal investigations. The twins were aged 9-11 years at the beginning of the observations, and 19-22 at their conclusion. The observations consisted of comprehensive somatic measurements and of the evaluation of biological maturity. The rate of growth of the twins, defined by the magnitude of yearly increments of body height, proved to be more concordant in MZ than DZ pairs. The appearance of the adolescent spurt occurred in the same year in 81 % of MZ and ca. 43% of DZ pairs. A very slight relationship was found between the rate of growth and final body height. The attaining of subsequent stages of sexual maturity in MZ twins was concordant in 88%, and in DZ twins in 30-39%, according to the respective stage. The body height curves were represented be means of three numerical parameters.

The analysis of quantitative inheritance is complicated by age dependent changes. It is possible to describe them by two separate 5-degree polynomials for boys and girls of one family. Supposing a parallel shifting of these pairs of curves for different families, it is possible to calculate the mean course of such a family specific pair even if only a few children were examined at a few termins. By use of these fitted functions it is possible to estimate the value of the quantitative variable for the examined children at a constant age and to eliminate the influence of sex. Similarly, it is possible to eliminate age-caused differences of the parents. Using the age-corrected values of children, mothers and fathers, it is possible to investigate the relations between the values of parents {not midparents !) and children by means of a two-dimensional polynomial approximation. The resulting complicated formulas can be visualized by plotting lines of equal character values of the children in a diagram with the character values of the fathers on the ordinate and those of the mothers on the abscissa. Effects of dominance and of epistasis can be demonstrated by this method. Some results using data of enzyme activities as an example are discussed.

A new family with the A2 type brachydactily is described. It is the first one observed in Italy and the sixth of the world literature. Brachymesophalangy of index fingers and/or second toes is the typical osseous malformation which was present in 14 individuals from 4 generations. The defect is transmitted by an autosomal dominant gene with high penetrance and variable expressivity.

Previous collaborative studies have shown the substantial superimposability of electrophoretic patterns of non-Ig plasma proteins in twin pairs only if MZ. The above findings provide the basis for (a) twin pair zygosity determinations and (b) studies aimed at discriminating genetic and environmental factors in the alteration of protein patterns in various diseases (especially neoplastic). Such studies require adequate standardization of methods, and the present paper offers a substantial contribution to the standardization of pattern comparisons.

A twin study on the significance of genetic factors for the variation in peak height and peak weight velocity, as well as in age at menarche and the development of secondary sex characteristics, is presented. Evidence of a rather strong genetic regulation of the occurrence of puberty was obtained in the analysis. The maximal height or weight gain (in cm/year or kg/year) seems to be, at least in girls, less influenced by genetic factors than the age at which it appears.

The problem of the equilibrium stability of a phenotypic selection process, with a single pair of autosomal alleles, has been numerically studied, on the basis of previously established reproduction differential equations.

A comparison of physical capacity, (measured by vital capacity, muscular strength and physical work capacity) in twin boys and controls failed to indicate significant differences. Intrapair correlations showed the MZ twins to be much more similar than the DZ twins in all the capacity measures. The correlations were lower, however, for both MZ and DZ twins for physical work capacity than for the other two capacity variables. When amount of physical exercise during leisure time is kept under control, the DZ twins tend to be more similar for physical work capacity or muscular strength, and the correlations tend to be of the same magnitude for MZ twins. Physical work capacity therefore appears, in this study, to be a more environmentally influenced variable than either vital capacity or muscular strength.

The rationale for using an approximate t′ test of the difference between the means of MZ and DZ twins is presented. This test avoids pooling the among-MZ and among-DZ twin-pair mean squares and has approximate degrees of freedom based upon the relative number of MZ and DZ twin pairs as well as the relative sizes of the among-MZ and among-DZ twin-pair mean squares. Sampling experiments simulating twin studies were used to show that the rate of Type I error for this t′ test was appropriate while other tests could give either too many or too few Type I errors depending upon the relative sizes of the mean squares and the relative numbers of MZ and DZ twin pairs.

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 Hecoefficient, coefficients of the within-pair association, Φ, derived χ2 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.

In 184 autopsies of death newborns, stillborn infants and aborted fetuses (mostly with congenital malformations), 57 (30.98%) umbilical cord anomalies were discovered (38 M and 19 F): 19 cases with knots (10.32%), 17 with arterial agenesis (9.2%,), 8 with focal fibrosis of Wharton's jelly (4.34%), 7 with varices and thrombosis (3.8%0), and6 (3.25%) with other anomalies. Thirtyone of the fetuses were born from first pregnancy, 32 were stillborn and 26 premature.

During the last decade, there has been a growing interest in the advantages that MZ twin pairs offer for studying the effect of environmental factors on the development of emotional disturbances. Much of this research has been aimed at investigating the relationship between childhood differences and later discordance with regard to schizophrenia in MZ twin pairs. A few studies have used similar methodology to investigate the development of neurotic reactions. There has been very little work dealing with the causes of discordance in the normal personality development of MZ twin pairs. The paper presents some of the results from a larger twin project which show the relationship between childhood differences and differences in adulthood. The study examined differences in oral, obsessive, and hysterical personality traits, as well as differences in phobic fears, general neurotic symptomatology, occupational and marriage adjustment in 50 relatively unselected MZ twin pairs. The results show that many of the same childhood differences which have been reported to be associated with the discordance found in regard to schizophrenia and neuroses, are also related to differences in personality structure, emotional and social adjustment in less disturbed MZ twin pairs. Other childhood differences, however, seem to be more specifically related either to neurotic or to normal personality development, pointing to the importance of studying the relationship between specific intrapair differences in childhood and differences in various areas of later personality development.