New data on the heredity of the M-N types in 420 families with 645 children conform precisely with the requirements of the genetic theory of Landsteiner and Levine. To date as many as 1580 families with 3379 children have been tested in our laboratory. According to our experiences, the three M-N types are entirely reliable for use in medicolegal cases of disputed paternity, provided that the individual who performs the tests is qualified.

New data on the distribution of the M-N types in 954 individuals are presented, as well as data on the distribution of the M-N S types in 394 individuals. The findings regarding the M-N-S types agree with previous reports concerning their distribution in Caucasoids. The medicolegal application of the M-N-S types is discussed and it is pointed out that more work must be done before the S and s factors can be safely used. What is needed most is methods for preparing anti-S and anti-s sera of satisfactory specificity and avidity.

Race, sex, nutritional status and cultural factors affect craniofacial morphogenesis. Out of these, sex is a major factor in craniofacial differentiation, because it can be stronger in one ethnic group and weaker in another. In this study, sex differences in genetic variance and heritability of 13 craniofacial traits are investigated. The study is based on a sample of 45 MZ and 101 DZ twin pairs and their 125 singleton siblings, 104 fathers and 103 mothers in 146 families drawn from an urban population of Chandigarh. Results of t'-tests for equality of the means reveal association of zygosity with the mean value of bigonial diameter in female twins and for none in males. Heterogeneity of variance is observed in about 50% traits in females as compared to 15% in males. This invalidates conventional within-pair genetic variance estimates for these traits. The revised genetic variance ratios are higher on an average in males than in females. However, there is greater MZ environmental covariance in male twins than their female counterparts. Family data indicate higher maternal effect for ear height, nasal height and frontal breadth, while greater paternal effect is seen in cranial traits. Sex-wise midparent-child regression coefficients show greater heritability in daughters for nasal traits and bigonial breadth, while sons show higher genetic component for head size measures.

Zygosity of triplet births in Japan was estimated by Allen's equation with the assumption that the rate of dizygotic (DZ) triplets reflects that of twins. Whereas the DZ triplet rate increased during the period from 1975 to 1994, reflecting the increase in the DZ twinning rate in the period, monozygotic (MZ) triplet rates remained constant from 1975 (28 per million births) to 1994 (23). The trizygotic (TZ) triplet rate gradually increased from 1975 (18) up to 1985 (29), and rapidly increased thereafter to 1994 (202). The higher TZ triplet rate since 1986 is most likely attributed to the higher proportion of mothers treated with ovulation-inducing hormones and partially to in-vitro fertilization in Japan. As for maternal age, MZ triplet rates remained nearly constant for all the maternal age groups except the youngest and the oldest ones. On the other hand, TZ triplet rates increased up to the age group of 30-34 years and decreased thereafter in almost every year. The TZ rate in the age group of 30-34 years slowly increased from 1975 to 1988 (63 per million births) and rapidly increased thereafter (314 in 1994). The TZ rate was statistically significantly higher in the period 1986-1994 than in the period 1975-1985 in each of the nine districts in Japan. Geographical variations in the TZ rates in the latest period have drastically changed from those during the period from 1955-1959 and in 1974.

Palm-print and finger-print patterns were studied in a series of 330 patients with congenital heart disease and compared to a control group of 200 patients with acquired heart disease.

156 patiens had associated malformations, while 174 other patients had isolated heart disease. Both groups were studied separately.

Simian creases are more frequent in the malformed patients than in the controls, but the difference is only significant in patients with multiple malformations.

A triradius in the positions t' is seen with a higher frequency in patients with multiple malformations and in patients with isolated heart disease than in the controls. The position t” however is only more frequent in the group of patients with multiple malformations, and tends to be associated more often with a ventricular septal defect and Fallot's tetralogy than with an atrial septum defect, aortic stenosis, coarctation and patent ductus.

Hypothenar patterns are more frequent in patients than in controls.

The results concerning finger-print patterns show a diminished frequency of arches in patients with isolated heart disease compared with controls and patients with multiple malformations. Variations between the different types of congenital heart disease were not important. They are partly in agreement, partly in disagreement with the results of other authors.

21 patients with familial congenital heart disease show an increased frequency of ulnar loops and a low frequency of whorls compared to the rest of patients.

This study does not include classical chromosomal aberrations and no malformation syndromes besides the Holt-Oram syndrome and the supravalvular aortic stenosis syndrome. The first one is characterised by an increased frequency of axial triradius in the t” position and of simian creases, while the second one seems to be without any dermatoglyphic particularity.

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.

We have compared breech twins and breech single births in a population recorded between 1974 and 1978 in 10 Belgian maternity centers. In 190 twin pregnancies, 38 first and 65 second twins were delivered in breech presentation. These twins were compared to 853 singleton breeches, of which 95 delivered by cesarean section were excluded. Data were stratified according to birthweight. No significant difference between twins and singletons was found in terms of perinatal mortality rates. However, Apgar scores below 7 at 5 minutes were significantly less numerous among first twins than among singletons. Therefore, first twins in breech presentation might be at lower risk of fetal distress. This difference should be taken into account in the management of first twins presenting by the breech.

In a random sample of 104 pairs of middle-class Caucasian, handedness-discordant twins six years of age or older, a significant relationship has been found between birth order and handedness in monozygotic twins, there being an excess of left-handed among first-born twins (P < 0.01). No such relation has been found in dizygotic twins.

To demonstrate the effects of home environment and parent-child relationship on personality and development, the author tells the life story of a pair of monozygotic twin girls reared apart. One, who grew up as a member of a large closely-knit family group, with mother-love and parental security, has become well-adjusted and happy in spite of severe set-backs. The other, reared as an only child by a hard and restrictive step-mother, and always required to do much hard work, became a tense and instable person, addicted to drugs and Anally probably committed suicide.

During the past two decades prospective epidemiologic studies have established the association between several risk factors and coronary heart disease. Elevations of serum cholesterol and blood pressure, obesity, lack of physical activity and cigarette smoking are among the factors which have been related to an increased risk of heart disease. We are now entering a period in which vigorous efforts will be made to modify these factors in order to prevent the occurrence of heart disease. An important part of this effort will be to determine to what extent these factors are genetically controlled and to what extent they can be modified by manipulation of the individual environment. Recognizing this need, the Field Epidemiological Research Section, National Heart Institute, NIH, has recently embarked on a study of cardiovascular disease risk factors in a large sample of adult male twins. The purpose of the present report is to describe the protocol and methods to be used and the importance of this study to current research in cardiovascular disease.

Birth statistics over a period of 5 years were analyzed to study epidemiological characteristics of twinning in Southeast Uttar Pradesh, India. The data revealed higher incidence of breech twins (11.84% of all cotwins) as compared to breech single births (2.18%). But the perinatal mortality and caesarean section rates were similar in both twin and singleton pregnancies. The cumulative twinning rate over the studied period was 11.70 per 1000 live births. The MZ and DZ twinning rates were estimated respectively as 3.67 and 8.03 per mill. The mean maternal age of sampled mothers was 26.42 years with one standard deviation of 5.30 years. The twinning rate for mothers over 35 years of age was about four times higher than that in mothers younger than 20 years. Incidently, the twinning rate was the highest at parity four and a non-linear curve could more appropriately be fitted to the series of data. Seasonal variations were observed for both twin and singleton births. The highest frequency of births was observed from August through October. But seasonal index for twinning rate showed a clear bimodal distribution with peaks in April (223) and September (167).

Hereditary factors involved in the determination of the size, relative position and type of pattern formed by the dermal ridges in the interdigital areas of the palm have been investigated by means of twin and family studies. The sample consisted of 566 individuals of European descent. The ridge-counts of patterns in the interdigital areas were determined. Correction factors were introduced to compensate for different average counts in each interdigital area. The correlation coefficients between family relatives were calculated using the ridge-counts. The coefficient for monozygotic twins was .88±.04 and for parent and child from .346 to .425 and for sib pairs from .328 to .412. There was no evidence of sex-linkage or of the effects of dominance. Variation appeared to be determined by additive genes but an appreciable amount of variation of non-genetic origin was observed. Bilateral asymmetry in the ridge-count, type of pattern and relative position of the patterns was evident. Concordance rates in twins and other family members and pedigree data provided further evidence of hereditary influence in the determination of the position and type of pattern in the interdigital areas.

Reading and mathematics performance data from a sample of 264 reading-disabled twin pairs and 182 matched control twin pairs were subjected to multivariate behavior genetic analysis. The factor structure of reading and math performance measures was found to be highly similar for both groups. Consistent with previous findings obtained using alternative methods, a significant heritable component to individual differences in reading performance was found both within the reading-disabled (h2 = 0.78) and control (h2 = 0.74) twin samples. In addition, a substantial genetic influence on mathematics performance was found (h2 = 0.51 and 0.60 in the reading-disabled and control samples, respectively), although shared environmental influences common to both members of a twin pair also contribute significantly to the variance in math scores of both groups (c2 = 0.44 and 0.37). Moreover, genetic influences accounted for 98% of the observed correlation between reading and math performance within the sample of reading-disabled twin pairs, and for 55% of the observed correlation in the control sample. Thus, individual differences in both reading and mathematics perfomance are highly heritable and appear to be caused by many of the same genetic influences.

The perinatal characteristics of 16 vaginal-abdominal deliveries of twins were evaluated. The primary indication for the cesarean delivery was compound vertex presentation (n = 4), prolapsed umbilical cord (n = 4), transverse lie (n = 7), and mentoposterior face presentation (n= 1). Ther outcome of Twin A was not different from that of Twin B. About 90% of the twins were eventually discharged on time. A significant correlation (R = 0.9722, p < 0.0003) was found between the reported rates of combined deliveries and cesareans in twins. The data suggest that a higher rate of combined deliveries is expected in practices where abdominal deliveries are performed more often in twin gestations, while in obstetric services with low cesarean rates in twins, combined deliveries seem to be unfortunate occurrences dictated by unexpected intrapartum events.

A total of 543 like-sex pairs of twins (407 MZ, 136 DZ) were sent mailed questionnaires on cigarette smoking, alcohol drinking and health conditions. The observed concordance rate for alcohol drinking was significantly higher than expected in both MZ and DZ pairs. The observed concordance rate for cigarette smoking was significantly higher than expected in the MZ, but not the DZ pairs. The observed rate of intrapair concordance for drinking was significantly higher than expected even in MZ pairs reared apart from infancy or very early childhood. Higher life satisfaction was observed more often in the higher alcohol consumers than in the lower consumers among MZ pairs discordant for alcohol drinking, while earlier onset of presbyopia was observed more often in the lower consumers. Physical symptoms, especially pains in the upper extremities, were reported more often by higher alcohol consumers than by lower consumers in the MZ pairs discordant for drinking.

Two hundred fifty-one twin deliveries between January 1, 1978 and June 30, 1983 at Prentice Women's Hospital and Maternity Center were reviewed. Cases were excluded if birth weight was less than 500 g, if gestational age was less than 26 weeks or if an antenatal fetal demise had occurred. Maternal demographic characteristics, delivery data and infant characteristics are described. The effect of providing care to a high-risk population of mothers in whom approximately 60% either deliver thair infants preterm or with a birth weight of less than 2,500 g is discussed in terms of costs of care.

The Authors have studied two sibs, 20 and 6 years of age respectively, which show hereditary cheratosis of the palms and sales, with spots of cheratosis in other loci too, in addition to dental dystrophia and expulsive gingivitis.

From the genetical point of view the most important factor is that neither parent is affected by the condition which on the other hand is generally considered as dominant.

The Authors suppose that the morbid genotype comes from the father's side of the family tree.

We described a case of pregnancy, delivery and peurperium of 28 years old multipara with twins pregnancy in bicornuate, unicollis uterus. Each fetus was placed in separate horn of uterus. Biological mature pregnancy was delivered by cesarean section. During the peurperium the involution disturbances of one of the uterus horns were observed. The case was discussed in context of other similar anomalies.

Further advances in research into the etiology of schizophrenia will depend on the identification of an unambigous indicator of the genotype associated with the development of schizophrenia. Such an indicator would permit accurate assessment of the relatives of probands as “affected” or not, so that the data generated in twin and family studies could be tested for the best fit to various genetic models that have been proposed. Schizoidia or schizoid personality has been considered by clinicians to be such an indicator, but it has been beset by semantic and logical difficulties. Most troublesome has been the extent to which the concept implies (merely) a phenotypic resemblance to schizophrenia, or a genotypie connection with it, or both. Four different but overlapping meanings for the concept of schizoidia are presented, in an effort to clarify the semantic and logic involved. Following Popper's notions about the testability and refutability of theories, the authors, identified with both monogenic and polygenic theories, apply the definitions to their first-hand observations of the cotwins in the Maudsley-Bethlem Schizophrenic Twin Study. Pushing the concept to its limit, 91 % of 22 MZ pairs and 45% of 33 DZ pairs contained “disordered” cotwins.

We describe a rare case of acardius in a triplet pregnancy terminated by Caesarean Section at 32 weeks gestation. Morphological and chromosomal abnormalities of the fetus as well as structural abnormalities of the placenta are presented. Cytogenetic analysis and examination of the single disc triplet placenta provide evidence for the two major theories of pathogenesis of acardius, the twin reversed arterial perfusion (TRAP) sequence and the genetic theory, which we believe are not necessarily mutually exclusive.

The Author sets out his standpoint on the value concerning the « forme fruste » of syndromes of multiple malformations expecially of those which have hereditary nature. He remembers the four types of « mandibulo - facial dysostosis ». The Author describes a family in which the different members were affected by this illness in incomplete form. In the last generation by two parents having the « forma frusta », two children were born, affected by a complete Mandibulo - facial Dysostosis both after having lived two or three months. After a close examination of medical literature referring the familiar forms, man examine all the genetical eventuality concerning the examined family. Man can reach to a conclusion that the appearence of two brothers with a complete forme, precociously dead, is quite surely imputable to « homozygotism » and consequently to double close of « pathological genes ».