Many chronological correlations in different plant and animal species, in populations, in human families, and between cotwins, prove the existence of characteristic biological times. Some such times also tend to be related to cosmic time, in which they develop and from which they are induced, resulting in peculiar composite times, such as the daily, monthly, or annual rhythms, that are the object of study of chronobiology.

Beyond these examples of exogenous chronological induction, the existence of a hereditary biological time is postulated, as the basic phenomenon in the relationship between time and life. The newborn scientific branch of chronogenetics is devoted to the study of the fundamental, endogenous genetic time, with its theoretical and practical, normal and pathologic implications. To explain and interpret the mechanisms of the hereditary biological time, the authors have developed a model based on the concepts of ergon (i.e., stability of the gene) and chronon (i.e., lifespan of the information). This Ergon/Chronon System is related to the gene, bringing into focus the fourth dimension and the dynamic aspects of the unit of inheritance.

The applications of chronogenetics extend to every expression of life, from the most primitive unicellular to the higher plants and animals. In the area of normal human traits, the study of the hereditary biological time contributes significantly to the interpretation of such phenomena as development, reproduction, homeostasis, and senescence. In the area of medicine, chronogenetics interpretes, unifies, and develops the temporal phenomena of inheritance. In a future perspective, chronogenetics appears to be fundamental for eugenics, preventive medicine, and prognosis.

Monthly chromosomal analyses have been carried out, from December 1971 to November 1972, on 4 male subjects aged 22 to 32. Over a total of 4 710 mitoses examined, the rate of aberrant cells (including gaps) was of 9.1% and there was no difference among individual yearly mean values. The average mitotic index, evaluated on 48 cultures, was of approximately 55‰. Significant differences (P < 0.025) have been found among individual yearly mean values (40-69‰). No seasonal increase of aberrations has been found; however, 12 of the 16 tetraploid cells were found in the winter months. In all subjects, the mitotic index reached its maximum in April-June (P < 0.001). The mitotic index and the percentage of aberrant cells were not shown to be correlated.

In order to study the influence of maternal and of paternal age on the incidence of standard trisomy G, two samples were compared, one of 335 trisomic and one of 330 normal children in the same age range.

The results show an increasing incidence of the anomaly with maternal age, whereas nothing could be concluded concerning paternal age.

In 1969 children of a multiple birth in the GDR made up 1.9% of livebirths and 15.3% of early neonatal deaths. The early neonatal mortality rate of children from a multiple birth was 95.7‰, that of all live-births 12.4‰. The cause was the low birth weight of children from a multiple birth (56.2% vs. 5.8% of all livebirths). Their low birth weight is the result of a hypotrophic development caused by malnutrition. The loss of children from a multiple birth (stillbirths, early neonatal and postneonatal deaths) was 143‰. International experience has shown that such heavy losses can be largely prevented by bed rest of the woman with a multiple pregnancy. We therefore strongly recommend early diagnosis and early in-patient care of women with multiple pregnancy.

A radiological investigation was carried out in a group of patients with the “cri du chat” syndrome. The most striking skeletal abnormalities associated with the 5p- chromosome anomaly include microcephaly hypertelorism, narrowing of the wings of ilia, which often appear rectangular in shape. In older patients additional consistent radiological features include large frontal sinuses, malocclusions, scoliosis, shortness of some metacarpal and metatarsal bones. The radiological investigations in the “cri du chat” syndrome, although of small diagnostic aid, appear to be useful for a detailed characterization of the malformations.

Premature delivery is 3-4 times higher in multiple pregnancy. About 12% of all premature infants result from twin pregnancies. Multiple pregnancy is therefore considered as a high-risk pregnancy, involving intensive care of the pregnant woman. The occurrence of toxicosis in twin pregnancies has in this way been reduced to almost 10%. The maturity or immaturity of twins seems to be qualified according to the weight of each single twin, irrespective of the twin partner. Small-for-date babies may be frequently found in twin pregnancies.

A total of 669 newborns from multiple pregnancies, including 15 triplets, have been examined. Full-term fetuses were 19.3% premature ones 60.7%, and dystrophic ones 20%. Of these, 58.4% were born in good conditions, 25.1% in average conditions (4-7 Apgar scores), and 16.4% in bad conditions (1-3 Apgar scores). Complications in the neonatal period were reported in 38.7% of cases (respiratory syndrome 21.2%, CNS injury 4.8%, developmental defects 1.3%, other complications 9.3%).

Twin mortality amounted to 10.5%, mainly due to hypoxemia (7.2%), cerebral lesion (2.4%), developmental defects (0.4%), and general edema (0.5%).

Measurement of the Y chromosome has been made in 508 males examined for military service. There was a normal Gaussian distribution of the length of the Y chromosome.

The frequency of mentally retarded males was significantly higher than expected among those with a comparatively large Y (Y/F ≧ 1.00). It is concluded that there may be an association between the length of the Y chromosome and certain types of mental retardation.

Out of 446 twin births in 1946-1971, 177 (19.8%) were stillborn or perinatally dead. The main reason of twin perinatal mortality is prematurity, which is also confirmed by clinical and anatomopathologic findings. The essential role in the reduction of perinatal mortality is being attributed to ambulatory “K” Centres through early diagnosis of multiple pregnancy and pregnant women hospitalization at 30-32 weeks of pregnancy.

The fundamental principles of genetic counselling in X-linked heredity are reviewed. As many as 18 X-linked eye diseases are described and discussed. These include diseases of the eye-ball, lens, retina, choroid, optic nerve, ocular muscles, and pigmentation, as well as the ocular manifestations of systemic skin or metabolic diseases.

The phenomenon of the so-called first memory has been studied in a sample of 350 pupils of an elementary school, 98 female university students, and 68 twin pairs of different age and zygosity.

In the average, the first memory refers to the 3rd-4th year of life, with a tendency to move forwards in relation to the age of the subject. This may be interpreted in terms of an unconscious selection operated by the memory, preferring more detailed memories and therefore producing the loss of undetermined and vague ones. Moreover, an unconscious tendency is also shown towards the recollection of pleasant memories. The first memory may be considered as a particular example of long-term memory.

The twin study shows that the hereditary conditioning of the phenomenon corresponds to 47%.

The perinatal mortality rate in multiple pregnancies has been examined both in literature data (where it reaches an average value of 17.5%), and on a sample of 619 twin deliveries from the Danzig population.

The degree of genetic determination of 4 digital and 16 palmar characteristics was investigated in an unselected series of 49 MZ and 51 DZ adult twins. Low indications of heritability were obtained for the qualitative traits, but 6 of the 8 h 2 estimates calculated for the quantitative measurements gave values above 0.70. In general, the results reported here are in agreement with those presented by other authors; however, the correlation coefficients observed for the A′d ridge count were lower than those of two other series. All palmar ridge counts seemed to be intercorrelated in a given individual; other expected relationships, however, were not observed. The fingerprints of MZ and DZ twins on the other hand, showed an unexplained difference.

The analysis of 682 newborns indicated that developmental defects accounted for 0.44% of the overall perinatal mortality of twins. The 3.7% higher mortality rate for second twins is frequently due to abnormal presentation and longer time-interval following the birth of the first twin.

The injection of human leukemic blood in chicken embryos before incubation determines a characteristic reticuloendotheliosis, which may be transmitted from embryo to embryo and even to the adult fowl. The viral agent responsible for this reticuloendotheliosis is filtrable and inactivated by heat. Intradermal injection of affected-embryo homogenates in leukemic patients determines a local allergic reaction. Electron microscopy has shown the existence of virus-like particles in the cells of inoculated embryos.

The complications of multiple pregnancy have been studied in a total of 619 cases of multiple pregnancies followed in the Danzig Department of Obstetrics and Gynecology from 1953 to 1972. On the basis of the results obtained, early hospitalization is recommended in cases of multiple pregnancies.

Aiming at a better clinical and genetic utilization of the sweat test in mucoviscidosis, the authors have carried out an evaluation of the variability and the genetic conditioning of the level of Na+ and Cl− electrolytes in human sweat.

The material covers 332 twin pregnancies (including 5 of triplets) of which 208 (62.7%) were premature deliveries and 124 (37.3%) deliveries at term.

Of the twin pregnancies included in the group examined 15.7% developed complications (gestosis and eclampsia, kidney and heart diseases, anemia, hydramnios). Spontaneous deliveries were 66.7%, operative deliveries 33.3%. A high mortality of the second twin (13.1%) is noticeable and it increases to 21.4% when operative procedures are applied to the first twin.