By dosing the serum-cholesterol in basal conditions in 5 0 MZ (25 ♂ ♂ and 25 ♀ ♀) and 50 DZ (16 ♂ ♂ 18 ♀ ♀ and 16 ♂ ♀ ) twin-pairs, the Authors found an intra-pair dissimilarity significantly different among the pairs of the two zygosity groups. On this basis, the genotypic origin of cholesterol biogenesis is pointed out. The twins, aged from 6 to 19, were all living with their respective families: nutrition and environment were thus the same for each pair.

After elaborating the data supplied by 351 questionnaires of a survey addressed to 1,241 twin-pairs, the Author shows differences in the behavior of MZ and DZ twin-pairs as to the sports phenomenon. By a first criterium of analysis, relative to sports practice in general, intra-pair dissimilarity is found to correspond to 6% in the case of MZ and to 85% in the case of DZ twin pairs. A second criterium of analysis concerned the kind of sport practiced by pairs concordant as to sports practice in general: the observed concordance as to the kind of sport practiced was more frequent in MZ then in DZ twin-pairs. By a third criterium concerning individual role and performance, the Author has been able to demonstrate that the distribution of DZ pairs, as to concordance, follows opposite patterns than that of MZ pairs. The Author concludes that sports activity, besides exogenous influences, (social environment, training, economic level etc.) is certainly also conditioned by genotypic, hereditary factors.

The Authors have analyzed the separate and combined influences of zygosity, placentation and sex on intra-pair birth-weight differences in 124 MZ and 124 DZ twin pairs. The highest influence on birth weight was found to be due separately to zygosity and placentation (respectively in cases of dizygosity and of a single placenta). The single placenta causes more circulatory unbalance and, as a consequence, more intrapair weight difference. This finding may help to explain the higher frequency of blighted fetuses in utero in MZ twin pregnancies and that of discordant congenital heart disease in female MZ twins.

The Authors report the finding of a difference in the diameter of the nuclei of myelocytes between males and females.

The diameter is greater in the females, with a significance of 5% (Student's t).

In cases of myelocytic leukemia the difference is even greater, suggesting the hypothesis that in this disease the cells may be polyploid.

The Authors present two MZ (one ♂ ♂ cf and one ♀ ♀) and four DZ (two ♂ ♂ and two ♂ ♀) twin-pairs aged from 7 to 12, selected among the Institute's pairs, as representing different etiopathogenetic mechanisms of stammering.

After summarizing the literature on the inheritance of logopathy, the Authors discuss the clinical cases and draw the following conclusions:

a) Stammering does not always follow the laws of dominance and recessivity;

b) There is no evidence of a sex-linked transmission;

c) Other logopathies, like battarism and tachylalia seem to possess a common substratus with stammering.

Après le discours d'introduction du Prof. Robert Montant, Doyen de la Faculté de Médecine, le Prof. Klein remercia les autorités et présenta ses hommages au Recteur, au Collège des Professeurs, en particulier à son maître, le Prof. A. Franceschctti. Il s'adressa ensuite aux étudiants et à l'auditoire en ces termes:

Messieurs les Etudiants,

Quelques-uns d'entre vous se demanderont peut-être où réside la nécessité d'introduire dans le programme clinique déjà si chargé une nouvelle spécialité, la génétique humaine, d'autant plus qu'elle a déjà la réputation d'être une science théorique pure et dépourvue d'intérêt thérapeutique.

Laissez-moi vous dire que la génétique humaine n'est pas une spécialité sui generis dans le même sens que les autres branches de la médecine. En effet, dans la hiérarchie des sciences médicales elle joue en quelque sorte « l'officier de liaison » dégageant de chaque discipline les données héréditaires et rassemblant ces éléments pour en faire une synthèse. Le généticien est donc plutôt un spécialiste malgré lui puisqu'il doit former un tout homogène des résultats si vastes et si divers obtenus dans les divers domaines des sciences biologiques et médicales. Pascal, sans le savoir, a très bien caractérisé la situation du généticien qui doit conserver une curiosité générale et tirer son matériel de toutes les sciences de la vie, lorsqu'il dit: « Puisqu'on ne peut être universel en sachant tout ce qui peut se savoir sur tout, il faut savoir peu de tout. Car il est bien plus beau de savoir quelque chose de tout que de savoir tout d'une chose ».

The Author reports on six subjects of a family (three generations) affected by congenital atresia of the lacrimal canaliculi.

In this genetical study of crosses between the Australian aborigines and Whites, in which the Áranda (Arunta) tribe at Alice Springs, in the desert heart of Australia, were mostly involved, many families were studied and their physical characters recorded. These include many F1s, also an F2 family and back-crosses to White, to aborigine, and to mixed. These studies provided an exceptionally wide basis for interpretation of the genes. It is evident that reciprocal crosses produce similar results.

Depression of the nasal root, a characteristic of the aboriginal skull, in crosses with the high European nose, probably involves not more than two or three cumulative genes. Sometimes the high, narrow European nose appears to be dominant (Fig. 15). High nasal bridge and narrow nose may be due to linked genes or to genes which affect both height and breadth of the nose. The brow ridges are an equally marked feature of the male skull, but they are frequently absent or much less noticeable in the female, so the manner of inheritance is not yet known. Wide nostrils of the aborigines again appear to depend on a small number of additive genes compared with the narrow nose of the white man. The lips of the aborigines tend to be thick throughout, but generally not everted. Eversion of the lower lip alone, especially in the central part, appears to depend on a single gene effect which is more marked in the homozygous than the heterozygous condition. This gene also occurs in Europeans and is anatomically quite distinct from the everted lips of the Negro.

In Tables I to VII about 15 physical characters are recorded for parents and children. Eye colour, skin colour, hair colour and form, colour of eyelashes and eyebrows, depression of nasal root, sunken orbits, width of nostrils, lips, length and breadth of head, cephalic index, car size and earlobes are included. The colour of hair, eyelashes and eyebrows may all be different in the same individual, the eyelashes tending to be darkest and eyebrows lightest of the three. Hair form ranges from near straight, through wavy to curly, the number of genes involved being very small.

Skin colour of the F1 is remarkably near the white, and when the F1 (male or female) is back-crossed to White the children mostly have white skin (Figs. 15-17). Some are near-white like the F1; but none darker than either parent have been seen. Study of the various crosses leads to the conclusion that a single main gene for melanin in the skin is present in the aborigines, together with a minor gene which alone produces brunet-white skin colour. The aboriginal skin, which is normally reddish mahogany or chocolate brown (not black, except perhaps in some northern tribes), is very subject to tanning (see Fig. 15) and evidently contains much less melanin than the full black Negro skin. The genetics of skin colour in the aborigines is thus very different from that of the African races. Both the skin colour and facial features in the hybrids are much akin to the Caucasian race, substantiating the view of anthropologists that such a relationship exists.

The skull is markedly dolichocephalic and about 20% smaller in cranial capacity than the European. It has two special archaic features — heavy brow ridges and the nasal notch. The latter involves a retreating glabella as well as a depressed root of the nose and sunken orbits. The Mongolian race has the nasal root depressed as in Neandertal man, but no nasal notch. These two, heavy brows and nasal notch, are the most persistent features in aboriginal hybrids. The skull most closely resembles some of the Mount Carmel Neandertaloids with a nasal notch, but the Australian race is neanthropic and not Neandertal, the Neandertals of S. Europe not having the nasal notch, and a low, sloping forehead being exceptional in the aboriginal.

The aborigines, especially those of SE Australia, with relatively hairy bodies, show relations with the Ainu, as well as with the jungle tribes of India. The Negrito element in N. Queensland is considered elsewhere (Gates 1959a). The gene (mutation) for tawny hair, especially in the children, probably originated in Central Australia and may be still spreading. Whether this is from a single event or from repeated mutations is uncertain.

The aborigines are similar to the Papuans in skin colour genetics (published later). Some Papuans show the nasal notch of the Australians. The overhanging nasal tip of the Papuans may occasionally be seen in the Australians. Miscegenation between aborigines and Australians is not a serious problem because (1) the two races are mutually friendly, (2) the number of full-blood aborigines is only 0.5%, (3) the half-caste married to White generally produces children with a white or near-white skin and near-European features.

Archaeological excavations show probably four successive culture levels, the oldest having a radiocarbon date of 8700 years. Whether the earliest entrance of man into Australia was during the last glaciation, when land bridges with New Guinea and Tasmania developed, remains uncertain.

First of all the authors summarize their present knowledge on the « brachydactylies », which consist of a large group of hereditary and congenital anomalies characterized by the shortness of two or three phalanges or metacarpi of the hands or feet. Then the authors describe a case of « brachytelephalangy » (shortness of terminal phalanges). The case concerns a boy of seven, who has brachytelephalangy in the 1st, 2nd, 3d and 5th fingers and the 3d, 4th and 5th toes. Alterations are bilateral and completely symmetrical.

The authors relate the radiologic aspects of the examined case, and, after having expressed a personal morphogenetical hypothesis on the radiologic picture itself, describe the genealogical tree of the patient. The hereditary nature of the malformation itself, which we find in other six members of the same family, is confirmed by a critical examination of this genealogical tree and by the study of the « Genius Familiaris » of the malformation, according to Gedda's conception.

The authors explain, then, the differential diagnostic criteria of the affection and, after having called the attention to some morphologic and clinical features of the examined case, they end by mentioning the rarity (only three cases in the previous literature) and the interest of the anomaly resulting from this radiologic-genetic study.

In continuation of the series of studies of racial crosses, this paper gives a genctical account of various race hybrids, in which Australian aborigines or Papuans are involved with Chinese, Malayans or Filipinos. Several families are traced through four or five generations, and some involve three or (in one case) four different races. Most of these racial combinations have not been studied previously.

The racial characters recorded in Tables include colour of eyes, hair, eyebrows, eyelashes and skin, form of hair and measurements of head and of ears. In addition various observations of brow ridges, orbits, eyefolds, nose, lips and mouth were made. The Mongolian brachycephaly is strongly inherited from male Chinese ancestors; also the eyefolds, especially the top fold, which is more or less independent of the epicanthic fold. In Malay crosses the face and head are often very narrow. Marked segregation in sibs can occur in head form (cephalic index), hair colour, hair form, skin colour and other features. It has already been shown that in the F1 of aborigines × White the skin is near white. The same is true of Papuan × White, and in addition the child's hair is flaxen or very light brown although the Papuans appear to have always black or near-black hair.

Incidentally, it was also observed that the Papuans not infrequently have marked brow ridges, depressed nasal root and sunken orbits like the Australian aborigines, indicating common elements in the ancestry of these two races.

The Papuan nose, commonly with an overhanging tip, differs in some respects from the Semitic nose, and appears to be an independent (parallel) development.

All contrasted human racial characters, such as hair form and colour, head shape, brow ridges, nasal root depression, size of ear and of mouth appear to depend on a small number of cumulative genes, generally without dominance. In how far these are alleles or based on genes at independent loci can only be determined by further investigations.

Endocrinology more than any other medical specialty requires consideration and cooperation of genetics. History of the rapid progress of clinical endocrinology in the last 50 years shows that human genetics has been lagging far behind endocrinology in clinical medicine. The psychologic reason seems to be the mechanistic trend of modern medicine and reluctance to use abstract logical thinking applied to material facts.

An individual mosaic for eye and hair color is described. Possibly the subject is heterozygous at a single locus with pleiotropic effects on both hair and eye color. It is proposed that a genetic change, most probably a point mutation, occurred in a prospective melanoblast during early development. Migration of the derivatives of this cell from the neural crest into the affected regions would account for the light-colored hair and eye. It is not likely that the present mosaic condition will be transmitted because it is most probably a case of somatic mosaicism.

The Author reports on the simultaneous appearance of a skin manifestation of the B.B.S. disease in female Twins. Partly diffuse and partly nodose infiltrations, with tendency to peripheral extension and central resolution constituted the clinical picture of the disease: (diffuse, small nodose variety of Boeck's sarcoids). In both cases the localisation was on the right cheek, the time-course was very similar. The histological picture was almost identical and was represented by infiltrations of epiteloid-cells with concentrical distribution.

The authors have observed a case of “Fuchs' atrophia gyrata chorioideae et retinae” in a girl, 17 years old, who presents in the same time an Alder's anomaly (azurophilic granulations in the neutrophiles). This girl was born from an intermarriage: the parents are first cousins and present also an isolated Alder's anomaly, which is moreover found in other members of the family (8 members affected in 4 generations).

These facts prove that Alder's anomaly can be transmitted in a dominant manner, which was not yet accepted till now, and also that the “Fuchs' atrophia gyrata chorioideae et retinae” probably represents the homozygous state of the gene of Alder's anomaly, the isolated presence of which permits to recognize the carriers of the gene of the atrophia gyrata.

The author reports cases of senile Scintillatio nivea of the vitreous present in the same family (one sister and two brothers). This is the third observation of familial cases of vitreous scintillatio; the first observation was noted in 1937 by Bietti. These familial cases of senile Scintillatio nivea of the vitreous make one suspect that metabolic disturbances are present on a constitutional basis in these familial subjects.

When calculating the chance of monozygosis from the results of a blood group study in a twin-family, it is desirable to use the complete information that is presented by these results and not only part of it.

A calculation-method in which the complete genetic-information is used is presented.

The use of the formulas is demonstrated by calculating the probability of monozygosis in two examples.

Our study on a kindred of spoon nails found among residents in Wakayama City, shows:

1. The kindred includes 36 affected members extending in five generations (Fig. 1). The seventeen marriages between affected and normal members of the kindred and which have more than two children, produced 29 affected, 16 males and 13 females, and 37 normal children 22 males and 15 females. This 37: 29 ratio falls within the range of the 1: 1 ratio of the affected and normal offspring. The sex ratio of the affected members, 16 males: 13 females, also is about 1:1. Thus, the abnormality seems to be due to a single autosomal dominant gene.

2. The penetrance of the gene in this family is apparently fairly high.

3. Regarding the expressivity of this abnormality, the concavity of nails is not always distinct especially in toes, while the expressivity of the gene in finger nails is more apparent.

The Author carried out tests for Barr's chromatine in 6 male subjects suffering from dystrophia myotonica and found concordance between chromosomal and gonadal sex.

The Author reports on the striking frequency of marked hereditary pathologic anomalies in the family of a proposita suffering from Biemond's Syndrome (diencephalic obesity, debility, neurologic and mental disorders, endocrine troubles, syndactyly of the feet and bilateral coloboma of the iris).

In the 173 membres of the family (non including the proposita) the Author found 17 cases of unilateral or bilateral coloboma (6 of whom died blind), 4 cases of iris malformation with atrophy of the stroma, 4 cases of females with serious unilateral or bilateral malformation of the hip-joint, 1 uncertain case of a male with Perthes disease, 4 cases of epilepsy (included a concordant MZ twin-pair), 1 case of a male suffering at the same time from imbecility and underdevelopment, 1 case of a female affected by coloboma, arachnoidal cyst and epileptic convulsions, and, further, some cases of myopia, single cases of strabismus, hyphoscoliosis, lipomatosis, hemolytic icterus and 1 case of a still-born child with atresia recti and hypoplasia of one arm. Besides a case of suicide, some members of the family are supposed to have been somehow « queer ».

It is probable that a degree of linkage exists between the genes for coloboma and epilepsy. All other findings, for the moment, may only be recorded. In order to reach some final conclusions other family studies will have to be added to the present one.

A description is given of the first case in the literature of practically simultaneous occurrence of central serous retinopathy in a monozygotic twin-pair.