Data on congenital total color-blindness were collected from the Japanese literature and through private communication, and tested for partial sex-linkage. Twenty sibships derived from consanguineous marriages, in which mode of relationship of the parents was fully known, were analyzed by using the direct method, and the crossover values 37.9-39.0% were found. Remaining 26 complete sibships were analyzed by using the indirect method, and a crossover value of 23.7% was obtained.

The higher recombination value derived from the direct method may possibly due to inaccurate information about paternal genotypes.

Aim. To evaluate the association between the incidence of leave of absence from work and perinatal outcome for the twin-pregnant woman.

Material and methods. A 20.2% sample of all twin-pregnant women between 1982 and 1988 (1,331/6,602) was taken at random from the entire material of twin deliveries in Sweden, archived at the Medical Birth Registry (MBR), National Board of Health and Welfare. For each woman in the sample, information on period(s) and reasons for leave of absence from work during pregnancy was obtained by inquiry to all Regional Health Insurance Offices throughout Sweden. A comparison of perinatal outcome was also made with information from the Danish Fertility Database and the Norwegian Medical Birth Registry.

Results. Duration of leave from work increased from 58 days in 1982 to 97 days in 1988 (trend analysis; t = 7.9, p <0.001). No association was seen between perinatal mortality for twins weighing. < 1,500 g and changes in the incidence of leave of absence. The incidence of twins with a birthweight < 1,500 g varied among the three countries, increasing significantly only in Sweden (trend analysis χ2 = 20.3, p <0.0001).

Conclusion. Although the number of days of leave of absence increased by 60%, there was no obvious association with perinatal mortality for twins weighing < 1,500 g. The incidence of Swedish twins with a birthweight < 1,500 g increased significantly, indicating that the effect of leave of absence from work on perinatal outcome may be less effective than previously thought.

Twins within pairs often have different weights at birth. A difference of 15% or greater is defined as discordance for weight and is considered to place one or both infants at risk. Temperament differences had been found in the neonatal period for full-term discordant cotwins, but not for preterm discordant cotwins, suggesting that continued gestation for discordant twins was a risk variable for early behavior. 30 pairs of fullterm and 17 pairs of preterm discordant pairs were followed at 6, 9, 12, 18, 24, and 30 months of age. Group differences were observed for the longitudinal maintenance of cotwin discordance in physical measures, with preterm cotwins becoming more like each other. In laboratory assessments, temperament differences no longer were observed between the larger and smaller cotwins. Questionnaires indicated that mothers generally did not differentiate between their larger and smaller cotwin children in temperament ratings, except for ratings of mood for the fullterm pairs. Thus, emotionality was the only temperament dimension that differentiated between the fullterm discordant twins both in the neonatal period and at later ages. In the main, it was concluded that the fullterm discordant twins overcame the adverse in-utero influences on early behavioral development.

The impact of genetic factors of the decay of the acustic function has been studied. Various tonal frequencies have been tested on a sample of 16 MZ and 16 DZ twin pairs, belonging to both sexes and to different age groups, i.e., fourth, fifth, and sixth decade.

A relatively high heredity coefficient is found with respect to the fourth and fifth decade.

The physical and mathematical characteristics of white light, monochromatic light, and laser light, are discussed with reference to the advantages offered by perimetry using a red helium-neon laser.

The Authors describe a pedigree including four certain and two probable cases of «Ehlers-Danlos syndrome ». All the affected subjects were born to consanguineous but apparently healthy parents. Of the three main symptoms of the syndrome, the patients presented hyperelasticity of the skin and hyperlaxity of the joints and of the ligaments, while the signs of cutaneous fragility were absent (« partial form » of E.-D. syndrome). In the first two cases it was possible to find some less common aspects of the E.-D. syndrome, such as ectasia of the trachea and of the main bronchi, anomalies regarding the eyes, the teeth and the nails, muscular hypotonia and hypotrophia, and particularly some skeletal manifestations (bending of the long bones, osteoporosis, anomalies of the methaphysis and epiphysis of the tubular bones, vertebral, thoracic and pelvic deformations).

The Authors emphasize the importance of these less common aspects of the E.-D. syndrome, and the similarity between these clinical signs and those found in other « heritable disorders of the connective tissue ».

The type of inheritance in this family (autosomal recessive) is discussed, in comparison to the commoner type (autosomal dominant) of inheritance of the E.-D. syndrome.

A 5 year old female child is described with mental and growth retardation, prominent occiput, low-set ears, moderate mid-face hypoplasia, congenital heart defect, mal-set toes, and a relatively high frequency of whorls on the fingers. The abnormal E18 chromosome found is thought to represent a partial deletion of the long arm with trisomy for a small terminal segment of the short arm as the result of a pericentric shift followed by crossing-over within the inverted shifted segment. Thus this case may represent a further example of “aneusomy by recombination”.

An unusual case is described in which a man was accused of the paternity of a child, and an expert reported him to be type RhzRh1, the mother as type Rh1rh and the child as type Rh2rh, thus excluding paternity. In repeat blood tests, the author confirmed the typing results on the putative father and the mother, but showed the child to be type Rhzrh instead of type Rh2rh, so that paternity was not excluded. Instead, the presence in both putative father and child of the rare gene RZ (or ry) could be considered circumstantial evidence that the accused man actually was the father. It is pointed out that the error could easily have been due to the mistaken use of anti-rhi serum in place of anti-rh′ serum. Such an error would be more apt to occur with a worker using the fallacious C-D-E notations, because the tacit assumption implicit in those notations that each agglutinogen has but a single corresponding antibody (and blood factor) would render unthinkable the concept of more than one kind of anti-rh′ (anti-C) reagent.

The Author reports on genetic problems of blood coagulation. Recent haematological reports on haemophilia, as for instance the differentiation of haemophilia into two different types (haemophilia A and B) bring up the question of the interrelations lig between the two genes responsible for the two types. The problem of recognizing female carriers is mentioned as well as the question of existence of female hemoghilian. It is pointed to further recent haemorrhagic diathese of genetic importance, PTA deficiency as well as the Hageman factor deficiency. Comprehensive investigations of factor VII deficiency on families, in Switzerland are of special genetic interest. These investigations have shown, that in those families, patients with complete deficiency of these factors are found, as well as members of the family not showing any haemorrhagic tendency being in complete health, but a quantitative deficiency of factor VII or Stuart-Power factor can be proved. A third group of members of these families is known to be healthy, showing a normal level of these coagulation factors. Healthy persons with a certain deficiency of factor VII or Stuart-Power factor can be regarded as heterozygotes.

The Authors describe the therapeutic effects obtained with Vincristine and Imuran in patients with acute leukaemia.

The results obtained with Vincristine indicate that the drug may be usefully employed in some cases of lymphoblastic leukaemia, both in the untreated phase or when the disease has become resistant to other antimetabolites. The remissions are of shorter duration compared with those obtained with other available compounds and are substantially confined to the lymphoblastic variety of acute leukaemia.

The preliminary clinical trial with Imuran has shown that the drug is better tolerated than 6-mercaptopurine and is able to produce good and satisfactory remissions in lymphoblastic and myeloblastic leukaemia, as well as in the blastic crisis of chronic granulocytic leukaemia, provided the dosage employed reaches 7-8 mg/Kg body weight daily.

Heberden's nodes or osteoarthritis of the finger joints are described in two identical twins. The appearance of the hands and the bone changes in individual joints as shown by radiographs are remarkably alike. That the twins are identical is indicated by agreement of eye color, hair on the fingers, tasting of phenylthiocarbamide and of 8 blood groups. Evidence of a tendency to mirror imaging in the distribution of the disease among the fingers is seen.

Osteoarthritis of the fingers occurs in these cases in the apparent absence of manifestations of osteoarthritis in other joints. Heberden's nodes is an hereditary disease but this seems to be the first description published of its occurrence in twins.

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.

The Anglo-Indians of India have been tested for the Tasting of P.T.C. The frequency of non-tasters in general shows that the population is intermediate between the European and Indian frequencies. They show a rise in the non-taster gene frequency with the rise in the dosage of European ancestry in their parentage.

The Mendelian law has further been established among the hybrid group as far as the frequency of non-taster gene frequency is concerned. In general the Anglo-Indians have 28.12 percent non-tasters of P.T.C., which shows a comparatively higher shifting towards the Indian range of values than towards the European one. It is explained to be due to the later practise of the Anglo-Indians to take in Indian brides, thus diluting the hybrids in favour of the base population.

After a historical review of the problem of progressive myoclonic epilepsy, the author makes a detailed clinical and genetic description of 5 families from the Valais canton, affected with the disease. The metabolic disturbances observed in these cases (urinary elimination of mucopolysaccharides) are given particular attention. The author further discusses the various classifications of myoclonic epilepsy which were established on the basis of clinical symptomatology, electroencephalographic tracings, pathological anatomy and biochemical findings.

A new syndrome in three siblings, a man and two women, now aged 33-45 years, is described. The syndrome consists of the following symptoms:

1. Oligophrenia (IQ about 30, Terman-Merrill test) with harmonic infantilism.

2. Dense cataract with onset in childhood.

3. Myopathy, mainly affecting proximal muscles but also facial, masticatory, and external ocular muscles. The myopathy probably had its onset at puberty and progressed, in 2 of the 3 siblings until they were confined to a wheel chair.

4. Signs of pyramidal tract involvement and slight ataxia, probably congenital and nonprogressive.

5. Deficient speech development.

6. Skeletal changes including thoracic deformity, scoliosis, pes planovalgus, shortening of the fourth toe, and osseous dystrophy especially in the hands and feet.

7. Hypergonadotropic hypogonadism with primary amenorrhea in one of the sisters, very early menopause in the other and pronounced testicular atrophy in the brother. There were no signs of other endocrine insufficiency and the secondary sex characters, body hair distribution and libido were normal. The karyotype was normal in all three siblings. The heredity was considered to be probably autosomal recessive. Since, therefore, a number of independent organs were affected, the syndrome has been assumed to be caused by a penetrating metabolic defect the nature of which is unknown.