SECTION 15 



HUMAN GENETICS 



15.1. Biological and Genetical Foundations of Great 

 Historical Features. Mario Tirelli (Rome, 

 Italy). 



A brief exposition of the phenomena, observa- 

 tions, criterions which may permit previsions 

 on the evolution of human groups, and thus on 

 the evolution of the reciprocal relations between 

 the groups themselves, from which depend pre- 

 cisely the development and the succession of the 

 great features and historic events. 



15.2. Phylogenetic Relationships of the Forms of 

 Erythrocyte Carbonic Anhydrase in Primates. 



Richard E. Tashian and Donald C. Shreff- 

 ler (Ann Arbor, U.S.A.). 



Characterization of the non-heme erythrocyte 

 proteins from a number of representative pri- 

 mate species of the families Lorisidae, Cebidae, 

 Cercopithecidae, and Pongidae has revealed the 

 presence in some species of two distinct mole- 

 cular forms of carbonic anhydrase (CA). These 

 forms are designated as CA-I and CA-II. In 

 addition to carbonic anhydrase activity, these 

 enyzmes also exhibit esterase activity toward a 

 and (3-naphthyl acetate, with CA-I possessing 

 markedly greater esterase activity than CA-II. 

 The electrophoretic separation patterns and de- 

 gree of esterase activity for CA-I appear to be 

 species specific. However, two variants of 

 carbonic anhydrase-I (CA-Ib and CA-Ic) have 

 been described from human hemolysates and 

 demonstrated to be under genetic control; 

 a variant of CA-I from an orangutan hemolysate 

 has also been observed. 



Additional evidence that the CA-I of different 

 species are homologous enzymes and that CA-I 

 is distinct from CA-II has been obtained from 

 immunodiffusion studies utilizing specific rab- 

 bit anti-human CA-1 serum. 



Often, both electrophoretic and immunolo- 

 logical characterization were necessary to establish 

 tentative phylogenetic relationships among spe- 

 cies. For example, although limited immuno- 

 gical differences could be detected within the 

 species of a particular family, they could usually 

 be readily separated on the basis of their com- 



bined electrophoretic patterns and esterase 

 activity. To a lesser extent, species exhibiting 

 similar electrophoretic patterns and enzyme 

 activity were shown to differ immunologically. 

 The application of these methods to the study 

 of primate evolution will be discussed. 



15.3. Modern Concepts in Clinical Genetics. Robert 

 L. Tips and G. Smith (Portland, U.S.A.). 



In modern practice clinical genetics can be 

 considered the application of genetic knowledge 

 in an effort to solve the diagnostic, prognostic, 

 and management problems of the patients and 

 their families. Subtle but severe medical emo- 

 tional, and socio-economic disturbances are 

 universally expressed by these families following 

 the introduction into the family environment of 

 a child with disease of genetic origin. A specifi- 

 cally trained team, coordinating their efforts, 

 can isolate and evaluate these problems, so that 

 the affected family can gain understanding and a 

 healthy adjustment. 



The patient, parents, and siblings are evaluated 

 in an appropriate clinic setting by the specialists 

 — the geneticist, who explores the total kindred 

 history with emphasis on reproductive patterns; 

 the physician, who evaluates the impact of the 

 pathological processes on the entire family; 

 the social worker, who relates to the problem 

 extended into the socio-economic milieu of the 

 kindred ; the technicians, who perform the battery 

 of genetic tests on each member of the family. 

 The elimination of emotional factors emanates 

 from conference discussion of the team after 

 their interviews and tests are complete. 



The discussion is amplified by a review of 

 four families whose problems were resolved by 

 the clinical genetic counseling team. 



15.4. A Genetic Discriminant for Diseases of Hetero- 

 geneous Origin. Bertram L. Hanna, A 

 Donald Merritt, Charles Wm. Todd, Jr. 

 and Terry L. Myers (Indianapolis, U.S.A.). 



Many diseases which segregate within families 

 as expected under a Mendelian model demon- 



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