title: Notes on the population genetics of fragile X syndrome.
abstract: Our analysis of fragile X-inactivation in normal and mentally retarded heterozygotes led us to conclude that a fraction of female carriers of the imprinted (fully mutated) allele is phenotypically normal as a consequence of X-inactivation. Taking this into account, we derived equilibrium equations for the fragile X [fra(X)] genotype frequencies. We also showed that small variations in the value of s (selection coefficient of affected heterozygotes) and r (imprinting rate during oogenesis) affect genotype ratios significantly.
authors.affiliation: Departamento de Biologia, Universidade de São Paulo, Brazil.
authors.forename: A M
authors.initials: AM
authors.lastname: Vianna-Morgante
authors.forename: P A
authors.initials: PA
authors.lastname: Otto
mesh_terms: D004303:Dosage Compensation, Genetic; D005260:Female; D005600:Fragile X Syndrome / Q000453:epidemiology / Q000235:genetics*; D005828:Genetics, Population; D005838:Genotype; D006579:Heterozygote; D006801:Humans; D008297:Male; D008957:Models, Genetic; D009866:Oogenesis / Q000235:genetics; D010641:Phenotype