Section 15 — Human Genetics 



monstrate a few points on which consanguineous 

 marriage and incompatibility of blood types re- 

 vealed to be the causes of mental deficiency. 

 Nosology of mental deficiency is discussed with 

 further investigation from the point of physio- 

 logical and biochemical genetics. 



15.41. Juvenile Amaurotic Idiocy in Sweden. 



Store Rayner (Lund, Sweden). 



During the years 1950-1959 I have collected 

 and personally investigated 37 cases of juvenile 

 amaurotic idiocy together with their relevant 

 family data. 



The incidence rate for the disease was esti- 

 mated to be 0.023 per cent, i.e. about 1 per 

 50,000 with an approximate heterozygote 

 frequency of 1.0 per cent. The incidence of first 

 cousin marriages among the investigated parents 

 of juvenile amaurotic idiots was 9.1 per cent. 

 This, together with the observed incidence of 

 juvenile amaurotic idiocy among the sibs of the 

 propositi (p= 0.26 ± 0.05) confirmed the earlier 

 hypothesis of a simple recessive and autosomal 

 type of inheritance. 



Hematological investigation of this, the 

 largest material of juvenile amaurotic idiocy 

 collected so far, showed that lymphocytic 

 vacuolation is an early and constant sign in this 

 disease. The average frequency of vacuolated 

 cells in the patients was 20.6 ± 1.6 per cent. 



Of the parents 95 per cent had vacuolated 

 lymphocytes when 500 cells were counted. The 

 frequency of vacuole positive individuals among 

 the sibs of the propositi was 65 per cent. The 

 mean frequency of vacuolated lymphocytes per 

 individual was about 1 per cent. 



These results, together with other findings in 

 the examined relatives and in various groups of 

 control materials, strongly suggest that the 

 occurrence of lymphocytic vacuolation in 

 healthy relatives of patients with juvenile 

 amaurotic idiocy is an expression of the gene 

 for this disease in heterozygous condition and 

 that, in the patients (homozygotes), it is a pleio- 

 tropic effect of this gene when present in "double 

 dose"'. 



15.42. A Test for the Detection of Latent Carriers of 

 the Duchenne Type of Pseudo-hypertrophic 

 Muscular Dystrophy. J. van den Bosch 

 (Amsterdam, The Netherlands). 



In 1958 a Dutch, seventeen-year-old sister of 

 several brothers, affected with the Duchenne 



form of muscular dystrophy of the sex-linked, 

 pseudohypertrophic and progressive type, was 

 examined by means of electromyography, in 

 connection with the genetical advice she had 

 asked about her progeny. The electroneurolo- 

 gist (Dr van der Most van Spyk, Utrecht) found 

 signs of myopathic changes in both her E MG and 

 in that of her mother. This finding resulted in a 

 wider-scale research into the significance of this 

 phenomenum: during 1960, 1961 and part of 

 1962 the author visited and examined "possible" 

 and "assumed" carriers for this disease in the 

 United Kingdom and made tape-recordings of 

 the electromyographic responses obtained by a 

 specially for this purpose designed portable 

 EMG apparatus. The recordings were subse- 

 quently replayed at the laboratory (The Galton 

 Laboratory, U.C., London) and the output of 

 the taperecorder was displayed on the screen of 

 an double-beam oscilloscope and photographs of 

 these visible patterns were taken. The results of 

 the statistical analysis of these recordings form 

 the subject of this communication. 



15.43. An Unusual Pedigree of Hurler's Syndrome. 



L. P. Chiasson (Antigonish, Canada). 



This study is based on a pedigree of Hurler's 

 syndrome for which the previously published 

 explanations — sex-linked genes, and recessive 

 autosomal genes — appear inadequate. The af- 

 fected individuals are children of normal 

 brothers whose normal wives are unrelated to 

 one another or to their husbands. The results of 

 investigations designed to detect heterozygous 

 individuals and/or low expressivity will be 

 presented, and the genetic implications of these 

 results will be discussed. 



15.44. The Zollinger - Ellison Syndrome as a Partial 

 Phenocopy of Adenomatosis of Endocrine 

 Glands. Paul Wermer (New York City, 

 U.S.A.). 



The Zollinger- Ellison syndrome consists of the 

 simultaneous development of severe peptic 

 ulcers and of solitary tumors of the islets of 

 Langerhans. In adenomatosis of endocrine 

 glands peptic ulcers of the same character occur 

 together with isletcell tumors, which are always 

 multiple and exhibit a specific microscopic struc- 

 ture: several other endocrine glands also show 

 excessive growth. The Zollinger-Ellison syn- 

 drome occurs only sporadically. Adenomatosis 



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