A survey of Gc and Hp polymorphism in Poland, designed to check results of earlier studies, gives the frequencies of Gcl and Hpl genes as 0.73 and 0.37 respectively.

Hand prints, estimates of degrees of skin pigmentation and percentages of Cherokee ancestry of 700 Indian pupils attending the Cherokee, North Carolina school were analyzed. The pupils are of mixed Cherokee-White origin. The average proportion of Cherokee ancestry is approximately 60%, the percentages being significantly higher in upper than in lower grades.

The frequencies of palmar patterns are similar to those recorded for other North American tribes. Frequencies of patterns in each of three palmar areas show significant associations with degrees of pigmentation, the highest association occurring between light pigmentation and accessory triradii in distal interdigital areas.

The Y/E index (Y/16-18 chromosomes) has been studied in a Swedish population of 74 men. The following results have been obtained: M = 0.734 ± 0.0238 with a range from 0.57 to 0.90. The values agree well with those of a Finnish population previously described. The use of the Y/E index in 15 paternity cases is exemplified.

Sexual development may be influenced by geographic factors (temperature, humidity, altitude, light), socioeconomic factors (nutrition, public health, family size), and genetic factors (population, familial heredity). Most of them are largely interrelated and difficult to define.

An anamnestic study has been carried out in Israel on Ashkenazi, non-Ashkenazi, and Arab women aged 19 to 60. The age of menarche appeared to be significantly different for Ashkenazi vs. non-Ashkenazi, while no significant difference was found between Arabs and either of the two Jewish groups. Highly significant differences were found for the length of the menstrual cycle, although this finding should be considered with caution. No significant relationship was found between age of menarche and length of the menstrual cycle.

Red cell acid phosphatase phenotypes were determined in 517 unrelated persons from Sweden (317 men, 200 women). The observed gene frequencies were pA = 0.372; pB = 0.558; pC = 0.070.

Experiences in 101 cases of disputed paternity with 167 men involved are reported. On grounds of red cell acid phosphatase phenotypes, ig men (in 18 cases) could be excluded.

In all 112 mother-child combinations studied the distributions of phenotypes were in agreement with the genetical hypothesis suggested by Hopkinson et al (1963).

In order to test if arm folding is a hereditary trait, 319 couples of parents and their 897 children have been examined. The distribution of the two phenotypes, D and G, is different from a O.5-0.5 distribution. No influence of sex nor age is observed. The matings are random and the mean number of children per family is the same for each type of mating.

The analysis of family data does not prove the hypothesis of a hereditary transmission of the trait, and important discrepancies are noted between observed values and those expected for genetic mechanisms with two alleles, D and G, of an autosomic or sex-linked gene.

Variations in skin color and palm patterns were investigated in two families in which the fathers are of mixed Negro-White origin and the mothers are Dutch. Segregation among the children indicates that two genes with cumulative effects are responsible for dark shades of skin in family A, whereas only one gene is responsible for dark skin in family B.

In family A the mother is heterozygous for accessory triradii and vestigial patterns in distal palmar areas, whereas in family B the father is heterozygous. Skin color and patterns in distal palmar areas do not occur independently among the children in family B, suggesting the possibility of linkage.

On the basis of the distribution of taste sensitivity to PTC in 50 parents-child(children) family groups, two different hypotheses are suggested for the mode of inheritance of this trait.

Several slide preparation procedures were studied in order to render a semiquantitative indication of an optimum technique or techniques, concerning the over-all cytological quality of the chromosome spreads effected by each technique. A method of scoring for karyotypically analyzable spreads is given. It is concluded that one of the techniques (technique D) be utilized for routine karyotypic studies while a combination of two of the techniques (techniques D and E) should be employed for more extensive studies.

A study of the anatomical correlation for the fifth-finger ridge count and its ratio to the correspondent correlation of a first degree relative (i.e., between sons and fathers and daughters and fathers) has been carried out in an inbred population of German ancestry living in Northern Venezuela for the last 127 years. This study revealed a remarkable straight relationship of the logarithm of the above ratio to the probability of having both genes at the locus (or loci) identical by descent, for the trait fifth-finger ridge count, i.e., the coefficient of inbreeding. The practical consequences of this finding for the estimation of inbreeding, if confirmed for other populations, are emphasized.

The heritability of two main line indexes (DLI and TLI), a palm crease index (API), and an ulnarity index (UI) were investigated by using twin pair methodology for quantitative traits.

The analyses of the data allow to conclude that both DLI and API, which have been used to evaluate the obliquity of the main lines and the distal crease of the palm, should not be considered as depending upon an important genetic component. Otherwise, data on TLI and UI, while showing inconsistencies with the theoretical expectations, may be considered as genetic traits.

Fifty marriages of twins to twins have been studied. Most of them have the characteristics of MZ twins. All have an identical outcome of their marriages within each set. This finding and others from the literature are consistent with the idea that marital stability depends in part upon one's original “blueprint” for physical and emotional health.

Two findings in this study, and others from the literature, are consistent with the idea that similarities at the chemical level may in general tend to promote a better understanding of each other and hence more congenial relationships: (a) all but one of the twin foursomes have lived closeby; three-quarters of them share the same house, even after they have had children; and (b) there is some degree of similarity in the ABO and Rh blood groups between husbands and wives in this sample.

The stably-married twins knew each other for an average of four years before marriage, whereas the divorced and annulled ones met only a few weeks or months before marriage.

In Hungary the frequency of multiple births has been decreasing. In 1920 the rate of multiple births was 23-5‰; by 1968 this rate decreased to 18.2‰, i.e., only 77% of the 1920 data. The male preponderance in twin births is lower than in single births, and in triplets actually a female excess can be observed. Furthermore, it can be observed that there are more boys than girls among the first-born of multiple births. The average birth weight of liveborn and stillborn twins, and of liveborn triplets is 2101 g, 1458 g, and 1723 g respectively. The ratio of MZ to DZ twins is about 30:70 in 1968. The frequency of DZ twin births increases with maternal age (the peak is now over 40 years) and birth order. According to the 1959, i960, and 1968 figures, both DZ and MZ twin births were significantly more frequent in mothers aged 16 or less than in mothers aged 17-19 years.

This demographic survey belonged to preparatory works connected with the setting up of the Budapest Twin Register which came into force on January 1st, 1970.