{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

article-1 - Copyright 2004 by the Genetics Society of...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Copyright 2004 by the Genetics Society of America Perspectives Anecdotal, Historical and Critical Commentaries on Genetics Edited by James F. Crow and William F. Dove Two Lessons From the Interface of Genetics and Medicine Anthony C. Allison 1 SurroMed, Menlo Park, California 94025 Thoughts are but dreams till their effects be tried. W illiam S hakespeare , The Rape of Lucrece W HILE growing up in Kenya, I became interested whereas in the majority of carriers sickling is observed only when blood is strongly deoxygenated in vitro , for in natural history, anthropology, and medicine. Natural history included Darwinism, and at Oxford Uni- example, in the presence of a reducing agent. The modern phase of research on sickle-cell disease versity after World War II, I learned what was then a novel concept: that natural selection results from began in 1949. Linus Pauling recalled how in 1945 he heard from W. B. Castle, a Harvard physician, about changes in gene frequencies in populations. The theo- retical basis of population genetics and of the effects of sickle cells and the need for deoxygenation to produce them. “It immediately occurred to me that sickle-cell ane- selection had been provided by R. A. Fisher and J. B. S. Haldane in England and by Sewall Wright in the United mia must be a disease of the hemoglobin molecule . . . . the molecules line up to form long thin strands . . . States. My parallel interest was the diversity of indige- nous peoples in East Africa, who belong to several lin- which would cause the cell to be deformed into the shape of a sickle or crescent” ( Pauling 1994, p. xvii). guistic and cultural groups. An attack of malaria forcibly directed my attention toward parasitic diseases and the This remarkable insight was confirmed when it was shown in his laboratory that hemoglobin (Hb) from need for doing something to relieve tropical maladies. The wish to participate in such a worthwhile task pro- patients with sickle-cell disease has a lower negative charge at physiological pH than does normal adult Hb vided motivation for a career in medical research. These rather diverse interests coincided to produce my first ( Pauling et al. 1949). The Hb’s were designated S and A; the Hb from patients with sickle-cell disease was major scientific contribution, which was published in 1954, 50 years ago. nearly all of the S type (apart from a minor component of fetal Hb). In parents and siblings there was a nearly equal amount of HbS and HbA, leading to the conclu- THE DISCOVERY THAT SICKLE-CELL sion that they were AS heterozygotes, whereas the pa- HETEROZYGOTES ARE RESISTANT TO MALARIA tients were SS homozygotes. This interpretation was con- firmed by family studies published in the same year James Herrick, a Chicago physician, observed sickle ( Beet 1949; Neel 1949).
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern