Heredity in ophthalmology / Jules François.

  • François, J. (Jules)
Date:
1961
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Heredity in ophthalmology / Jules François. Source: Wellcome Collection.

    9/750 (page 5)
    PREFACE In 1865 a Moravian monk, Johann Mendel, formulated the fundamental laws of heredity while cultivating peas in a garden in Brünn. After remaining forgotten for thirty-five years, these laws were rediscovered by Tschermak, Correns, and DeVries. New concepts of the gene, mutation, linkage, crossing over, and expressivity or penetrance; physicochemical and histochemical studies on the genetic constitution; and exhaustive investigations of family trees and sibships have given rise to the new science of genetics. The aim of this science is to study the origin, the transmission, and the outcome of the gene. The study of the constitution of an individual is of supreme importance since we know that disease is often the result of a disharmonious interaction between internal and external factors. The genetic make-up contributes largely to the development of the constitution of the individual. Therefore, medical genetics must strive, above all, to study in detail the nature of the genome. Investigation of the methods of transmission of genes is an essential contribution to this end. The aim is identical in ocular pathology. It is not sufficient to collect reason¬ ably interesting pedigrees; one must try to understand the constitutional basis upon which the ocular disease has originated. Recent discoveries concerning the inheritance of glaucoma and the abiotrophies of the retina permit great hopes in this respect. In order to emphasize the importance of genetics, it is sufficient to recall that in 1922 ophthalmia of the newborn infant, congenital abnormalities, and other conditions were responsible for only one third of the cases of blindness in the schools for the blind in England. In comparison, in 1944 congenital and hereditary abnormalities alone were responsible for more than two thirds of the cases (Sorsby). To believe that genetics is a barren science is a grave error. We have already at our disposal an important therapeutic arsenal which includes surgical treat¬ ment (for congenital cataract, for example), medical treatment (for diabetes, for example), and knowledge for use in preventive medicine (Rhesus factor, responsible for the hemolytic disease of the newborn infant, for example). We may rest assured that the list is not yet complete and that the future holds agreeable surprises for us. 5