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.

In a previous work on oral contraceptives and tranquillizers the author had postulated an expansion of the cerebrospinal fluid at the time of the vasopressin inhibition.

In the present work he has now examined, by means of echoencephalography, the reaction of the third ventricle and intraocular pressure after alcohol ingestion. Ten consanguineous subjects were studied.

The results show an increase in diameter of the third ventricle and a decrease of the intraocular pressure as a result of alcohol ingestion. Both these signs indicate a decrease of the cerebrospinal fluid pressure. This decrease, in its turn, shows the rise of the nervous excitability. The author suggests that the third ventricle may act as a resounding cavity capable to modulate the mesencephalic reticular-formation activity and the diffuse thalamic system by means of the electric gradient potential and its pulsation.

In the case of heredo-familial diseases it is desirable to identify the abnormal genotype, the homozygously abnormal individual, if possible while still asymptomatic, and the carrier of the abnormal gene or allele, the heterozygote.

So far as Wilson's disease is concerned, it is possible to diagnose individuals as presymptomatic homozygotes by finding Kayser-Fleischer corneal rings on slit-lamp microscopy, or by demonstrating increased liver-copper on needle biopsy.

False-negative results are common, however, and more reliable identification of the presymptomatic homozygote as well as the heterozygote can be achieved by studies of the physiology of copper, using tracer doses of radioactive copper, 67copper, which has a physical half life of about 61 hours. Using this method it can be shown:

1. That there is prolonged retention of copper in the whole body in both homozygotes and heterozygotes, the former showing more prolonged retention than the latter.

2. In both there is retention of copper in the liver, again more marked in the homozygote than in the heterozygote.

3. There is decreased intestinal excretion of copper in both cases as manifested by decreased biliary radiocopper and decreased stool radiocopper, and again this is most marked in the homozygote.

4. Urinary excretion of radiocopper is usually increased significantly in the homozygote, but is usually normal or only very slightly increased in the heterozygote.

5. The additional finding of impaired ceruloplasmin biosynthesis is sufficient usually to distinguish with certainty between the presymptomatic homozygote and the heterozygote.

Juvenile amaurotic idiocy is an autosomal recessive disease with onset around 6 years of age. Principal symptoms are: blindness; dementia; focal and generalized seizures; cerebellar, striatic, and pyramidal deficits; and psychosis. The course is progressive, common duration 10-20 years. Epidemiological studies are very few, but important work has been done by Sjöstrand and Rayner in Sweden.

The preliminary results of the present study indicate a rather higher incidence of the disease in Denmark. It is furthermore demonstrated that there is no evidence of consanguinity between parents, and that the disease is geographically evenly distributed. These findings are in contrast with earlier epidemiological investigations.

Three observations of heredopathia atactica polyneuritiformis are reported. Two of these correspond to cases of Refsum's disease, though showing a very different evolution. The third one also seems to be a case of Refsum's syndrome, though showing different contradictory clinical and biochemical features.

The difference between the two clinical pictures, heredopathia atactica polyneuritiformis and “Refum's syndrome” is stressed, together with their individual variability. A review of the literature clearly shows that in none of the cases of “Refsum's syndrome” described so far have any biochemical errors been identified.

The cases with a symptomatology similar to heredopathia atactica polyneuritiformis represent a challenge to further intensive studies.

The Authors report the evolution of a case of congenital pigmentation of the optic discs (Beauvieux's syndrome-like).

There was no evidence or history of hereditary or metabolic diseases, but it is important to point out the unusual age of the mother, who was 14 years old.

Type II hyperprolinemia is a rare metabolic disorder associated with mental retardation, seizures, and EEG anomalies.

The authors describe a Sicilian family, detected screening for aminoacidopathies by the method of Scriver, in which three siblings have high levels of serum proline and urinary pyrroline-5-carboxylic acid, without any signs of associated anomalies.

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.

Two cases of suspected oedema of the optic disk are presented and references is made to the spatial summation technique as a means of diagnostic classification. Comparison of the results obtained with white and laser source pointed to the superiority of the latter.

Campimetric pictures in several cases of chiasmal syndrome are presented. Comparison between white light and laser visual field data shows that earlier and more precise evidence of visual field defects is obtained with the latter method.

A survey of color vision defects was performed on a random sample of 138 Santiago male school children aged 14-15 years. Over-all incidence of red-green defects was found to be 4.34 percent. Blue-yellow minor defects were found in 17 cases (12 percent). The following major defects were found: extreme tritanomaly plus extreme tetartanomaly (1 case), and extreme tetartanomaly plus weak tritan defects (2 cases).

These results suggest a probable incidence of 2.16 percent of congenital blue blindness in the general male population of Santiago, Chile.

The two types of amaurotic idiocy, gangliosidosis and ceroid lipofuscinosis, are characterized by biochemical, ultrastructural, and electrophysiological differences. They are in fact two different clinical entities, both resulting from a congenital metabolic trouble.

Six clinical cases of ceroid lipofuscinosis are presented and the diagnostic importance of the ERG is stressed.

The results of pilot studies of the activities of platelet monoamine oxidase (MAO) and catechol-0-methyl transferase (COMT) in the blood of selected schizophrenics and the families of schizophrenics is presented.

No statistically significant difference was found between the blood COMT levels of 21 control subjects and 26 schizophrenics, whereas the values found for platelet MAO activity were significantly lower for the schizophrenic group than for the control group.

In one acutely disturbed first-admission schizophrenic the platelet MAO activity increased to a normal level in parallel with the clinical improvement, whereas in the relapsing schizophrenics the platelet MAO activity remained at its initial level although the clinical picture improved. No consistent findings with regard to the platelet MAO activity emerged from the study of 3 families having a history of schizophrenia.

Six persons in four generations had congenital severe deafness and progressive mid-life visual failure. The 53-year-old proband and her 9-year-old son, studied in detail, had severe neural hearing loss and optic atrophy, much more severe in the mother. Her vision was 20/80 in each eye while her son's vision was normal. No cause for the hearing or visual loss was present except heredity.

The proband's father, seen years ago at the age of 68, was congenitally deaf and had progressive visual loss with optic atrophy. By history, the proband's two maternal aunts and paternal grandmother had this same syndrome. The syndrome, transmitted by dominant mode, is unique and distinct from other familial syndromes of visual and hearing loss, including those described by Usher, Refsum, Alström, Cockayne, Norrie, Small, Sylvester, Rosenberg and Chutorian, and Tunbridge and Paley.