China
Africa
Explore chapters and articles related to this topic
J.B.S. Haldane (1892–1964)
Published in Krishna Dronamraju, A Century of Geneticists, 2018
In a spirited defense of his approach, in response to a criticism by Ernst Mayr (1959), Haldane (1964) wrote: “Our mathematics may impress zoologists but do not greatly impress mathematicians. Let me give a simple example. We want to know how the frequency of a gene in a population changes under natural selection. I made the following simplifying assumptions: The population is infinite, so the frequency in each generation is exactly that calculated, not just somewhere near it,Generations are separate. This is true for a minority only of animal and plant species. Thus even in so-called annual plants a few seeds can survive for several years,Mating is at random. In fact, it was not hard to allow for inbreeding once Wright had given a quantitative measure of it,The gene is completely recessive as regards fitness. Again it is not hard to allow for incomplete dominance. Only two alleles at one locus are considered.Mendelian segregation is perfect. There is no mutation, non-disjunction, gametic selection, or similar complications.Selection acts so that the fraction of recessives breeding per dominant is constant from one generation to another. This fraction is the same in the two sexes.
Granular type I corneal dystrophy in a large consanguineous Tunisian family with homozygous p.R124S mutation in the TGFBI gene
Published in Ophthalmic Genetics, 2019
Yosra Bouyacoub, Yousra Falfoul, Mariem Ouederni, Marwa Sayeb, Aschraf Chedli, Mariem Chargui, Hela Sassi, Ilhem Chakroun Chenguel, Francis L. Munier, Leila El Matri, Sonia Abdelhak, Monia Cheour
Corneal grafting for advanced GCD1 produces satisfactory results, although recurrence has been seen as early as six months following the procedure. Most individuals with GCD1 have preserved eyesight for many years and require keratoplasty only in the sixth or seventh decade of life. However, a small percentage of patients experience rapid progression of clinical manifestations and early-onset visual deterioration. These patients require keratoplasty in the second decade of life, especially in the event of p.[R555W] homozygosity with incomplete dominance (25).