Pregnancy duration was examined in 389 multiple pregnancies out of 29,656 general deliveries. Mean duration of multiple pregnancy appears to be 258.5 days, i.e., 23.1 days shorter than general pregnancy, which is statistically significant (t = 32.16, P < 0.001).

There is high linear positive correlation between fetal weight and length, and between these and maternal abdominal circumference. A highly significant multiple correlation exists between fetal weight and length and maternal abdominal circumference in multiple pregnancy.

The Authors report the results of a cytogenetical investigation on a group of 140 Down's syndrome patients: nine of them had a translocation (D/G or G/G) and four a mosaic (trisomy 21-22/apparently normal); a mongol girl had 48 chromosomes due to the presence of a small centric chromosome and 21-22 trisomy. All other patients had a regular 21-22 trisomy. Some additional morphological anomalies are described, but interpreted as being expression of the normal human karyotype's variability.

A large Brazilian family, of white ancestry, in which several members presented a spinocerebellar ataxia, was studied. Informations were obtained covering six generations, in a total of 337 related individuals. 116 of them were examined by the author. 18 presented the disease, and of these 10 were alive at the time of the study. Besides them, by her descendents, it was possible to find a carrier of the gene, who died in a preataxic age.

The disease is transmitted by an autosomal dominant gene, and appears at the age of 38.33 ± 1.74 years. Cerebellar, posterior chord and pyramidal alterations were present in the sick persons. Almost all the patients presented disturbances of the temperature sense. The disease had not lowered the viability and fertility of the affected persons.

The antenatal management and outcome of 31 higher-order multiple gestations, 24 triplets, six quadruplets, and one set of quintuplets were analyzed. Bedrest was advised as soon as the diagnosis was made; hospitalization along with the administration of betamethasone and phenobarbital was begun during the second trimester. Caesarian section was performed on 13 women (42%). The overall mortality rate was 14.8%; excluding neonates less than 28 weeks of age, however, it became 7.5%. The primary cause of death was respiratory distress syndrome.

The Authors have studied 87 pairs of MZ-twins, determining for each individual the values of both Fusional Convergence (FC) and Simultaneous Macular Perception (SMP) by means of the major amblyoscope. They have found a high degree of discordance in the FC, corresponding to 80,5 per cent, while the SMP showed a lower degree of discordance (17,2 per cent.). The Authors have observed that the highest values of FC mostly belong to the “leader twin”; they make the hypothesis that the unusual discordance of the FG in the MZ-twins depends on a higher level of will in the “leader twin”, thus representing a test of psychological discrimination between MZ-twins.

Dosage of the hematic level of ATP has been afforded in 20 (7 MZ and 13 DZ) twin pairs aged 4-6 years. The intrapair correlation coefficient has been calculated and resulted to be significantly higher in MZ than DZ twin pairs. The hereditary “quantum” in the determination of the hematic level of ATP was also estimated and resulted to be of about two thirds.

Statistical studies have shown a significant correlation between maternal pregestational weight and duration of pregnancy (i.e., a low weight may cause a shortening of pregnancy). Duration of pregnancy is further correlated to the weight gain (i.e., it is shortened by an insufficient gain). This phenomenon is observed in thin women, but not in women of heavy weight before the pregnancy.

The studies of weight losses obtained through hypocaloric or sodium-free diets or diuretics, show that a sudden weight loss may cause a shortening of pregnancy duration. This is verified in patients with normal or insufficient weight gain and starting with a normal or small weight, but not in overweight patients or with an important weight gain.

This study demonstrates the dangers of excessive measures toward prevention of toxemia. The decision of compulsive weight loss in mothers with multiple pregnancy must be well thought and carefully applied, for excessive measures could reduce the duration of pregnancy and thus increase the risks of perinatal death.

Cytogenetic studies were performed in six clinically typical cases of Turner's syndrome. In five of them an XO chromosome complement was observed. In the sixth case the chromosome number appeared normal, but karyotype analysis revealed the presence of three large metacentric chromosomes similar to No. 3. A diagnosis of presumptive isochromosome for the long arm of X was suggested by the autoradiographic evidence of late replication and by the presence of larger than normal Barr bodies and drumsticks.

The incidence and evolution of patent ductus arteriosus (PDA) was evaluated in twins and preterm singletons with birth weight ≤ 1750 g admitted to our Department in 1987 for respiratory distress syndrome (RDS). Screening by echocardiography and Doppler-flow studies (AT MK 600) was performed on the third day of life. Out of 91 neonates who needed intubation and ventilation during this 12-month period (23.8% of admissions), 40 weighed less than 1750 g and of these 40, 14 were twins (35%). Hemodynamically significant PDA was documented in 13 patients; of these, only 5 were preterm singletons and 8 were twins. Two twins weighing < 1000 g received no therapy for ductus closure; one ductus closed spontaneously, the other had an early demise. Three twins and 2 preterm singletons received indomethacin; one of the twins needed a second cycle for definitive ductus closure. Three twins and three preterm singletons underwent surgery, while one twin died on the 10th postoperative day. Screening and early therapy of PDA during RDS could be of great clinical importance. Twinning seems to play a role in the incidence and evolution of PDA and this needs to be evaluated in further studies.

One of our patients with chronic myelocytic leukemia has a twin brother. The twins, 31 years old, show similar physical appearance. Both have blue eyes, brown hair and are right-handed. Anthropometric measurements and fingerprint patterns are matching. Blood group antigens, serum factors and PTC tasting are identical. Blood group antigens of the parents have also been determined. It has been calculated that the probability that the twins are MZ is higher than 99.8%.

The twins were the result of an uncomplicated pregnancy. There are no other siblings. No family history of consanguinity, hematological disorders or cancer was given. They spent their childhood on a farm. Both have not been exposed to drugs, benzene or radiological procedures, apart from routine X-ray films of the chest.

Our patient, who is still working on his farm, had been referred to a hospital in June 1959, because of a knife wound of the chest with a myocardial laceration and pericardial tamponade. White blood cell count at that time was 22300 with 3% basophils.

In April 1962, the diagnosis of chronic myelocytic leukemia was established. Findings included hepatosplenomegaly, leukocytosis with a marked shift to the left, hyperplasia of granulopoiesis in the bone marrow and diminished leukocyte alkaline phosphatase activity. In the following years the patient was treated with cyclophosphamide, splenic irradiation and busulfan. Busulfan is continued at present at low doses.

A fluorescence staining method of the male chromatin body in human interphase nuclei is described.

The Authors studied the leukocyte alkaline phosphatase (LAP) activity in 40 subjects with Down's syndrome. The age of the patients ranged from one week to 15 years. Chromosome analysis was carried out in 13 cases. 42 normal children of the same age as the patients were used as controls. The mean value of LAP in the patients with Down's syndrome was 175.5 and in the control group 108.8. In the latter group the LAP activity was clearly influenced by the age; the highest values were obtained in children under 11 years of age. The regression coefficient of the LAP on the age in the control group was –3.73. In the patients with Down's syndrome the differences observed between the various age groups were not statistically significant.

Chromosome studies showed a 21 trisomy in 12 cases; in one case a 15/21 translocation was found. The latter case presented an elevated LAP activity.

The Authors support the hypothesis that the gene or genes controlling LAP activity are located in the 21 chromosome and that the LAP activity may vary under the influence of several factors within the limits of the genetic control.

1. There is probably no special hereditary disposition for the localisation of the tuberculosis at the skin.

2. The partial selection of the hitherto made casuistics of twins explains the contradiction to the literature.

3. The general tuberculosis is in the sense of Diehl and v. Verschuer preponderating concordant by monozygotics twins and discordant by bizygotics twins.

The monozygotic (MZ) cotwin control method was employed to elucidate possible environmental determinants of systolic blood pressure (SBP), diastolic blood pressure (DBP), serum cholesterol and triglyceride levels. A population-based twin sample of 73 male and 77 females MZ twin pairs was recruited from 12 junior high schools in Taipei city. Intrapair differences in blood pressure were negatively associated with intrapair difference in vegetable preference, attaining significance for DBP in males and SBP in females. Cholesterol was positively associated with milk consumption and preference for sweets, fried foods, meat and fish. A negative association was also observed between choleserol and vegetable preference. These associations for cholesterol were significant in males only. Triglyceride level negatively associated with preferences for sweets and vegetable, attaining significance for vegetables in both males and females and for sweets in males only.

The rates of infant mortality of twin individuals were 4.38% and 7.76% for mothers healthy and nonhealthy after delivery, respectively, and the difference is significant at the 0.01 level. The lowest infant mortality rate was seen in the mothers with paid work during pregnancy (4.56%), followed by the mothers engaged only in housekeeping (4.72%) and by those self-employed during the pregnancy (4.99%). Infant mortality rate for MZ twins decreased with increased monthly expenditure of the household, whereas the rate for DZ twins remained constant with expenditure. Socioeconomic factors still affect the infant mortality of twins, and the infant mortality rate can be improved.

A case-control study was conducted on the termination of menstrual life on mothers of twins. It involves a much larger data base and finer analyses, and makes use of the same methodology of a previous study. The time interval between the twin and the last confinement proved to be shorter in twin-bearing mothers than in a matched set of controls with singletons only after blocking of the effect of birth order, and despite the similarity of maternal age at delivery and confinements numbers. Mothers of like-sex twins only appeared to terminate reproductive life earlier than controls. The separate study of maternal age at twin confinement shows that the earlier the twin birth the shorter the menstrual life thereafter. Both like-sex twin births and early maternal age at delivery of a twin pair have the same shortening effect on subsequent menstrual life without clear evidence of additivity of effects as if both occurrences were alternatives with similar biological effects. Comparison of the results of the current study with those of our earlier analysis shows consistency on above results. However, the current study could not reproduce previous results on the role of unlike-sex twins or late maternal age at delivery on time to last confinement; yet, they cannot be discarded. It is suggested that increased power of interaction analyses and tighter matching of controls with respect to sex might improve the conclusions of subsequent studies.

The Authors have studied 56 twin pairs (31 MZ and 25 DZ) under the aspect of the psychomotor reactions they have shown while watching motion pictures. The most closely considered reactions have been head posture, arm and leg posture and mimic reactions. The analysis of the reactions was carried out on photographs taken during the projection of the films and then compared for the degree of similarity of the postural or mymical reactions. The degree of similarity was rated according to the following scale: concordant, similar, dissimilar, discordant.

The results obtained have shown that head posture (on which the influence of conscious mobility is higher) the hereditary factors have a clear influence; while for arm posture and especially for leg posture during projection the influence of hereditary factors could not be proven in any appreciable degree; this finding is thought to be related to the low influence of conscious mobility and with the sitting position being conditioned by environmental factors.

For mimic reactions the influence of a hereditary component is always clear, but from this point of view a marked difference is found between mimic reactions to anxiogenous and to comical films. Reactions to the latter reveal a higher, characteristic degree of difference between MZ and DZ twin pairs, i. e. a higher degree of hereditary influence.

The Authors have made further studies on the family trees under the aspects of previous twinnings and of previous personal pathological anamnesis, increasing the known case histories and strenghtening the conclusions reached by Gedda in previous 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.