Cancer by negative heterosis: breast and ovarian cancer excess in hybrids of inbred ethnic groups

摘要: Breast and ovarian cancer rates in Pakistan are significantly higher than neighboring countries. The rate discrepancies cannot be explained with of their risk factors. We propose that observed excess is due to development by negative heterosis. Heterosis occurs when a hybrid has phenotypic characteristic different from either parent (hybrid vigor). At molecular level, heterosis heterozygote one the two alleles inactivated. Gene inactivation methylation cytosine promoter region gene. Initiation allele linked factors like stress, gender, diet, or another In heterozygote, tumor-suppressor leads monoallelic expression. This increases same way increased individual who inherit single mutated gene (hereditary syndrome). both, inherited syndrome, develops after second (second hit hypothesis). population, conditions favor those mating large number homozygotes because they produce heterozygotes. Among heterozygotes, there an chance some hybrids will develop Pakistan, were favorable for country high ethnic groups brotherhoods all which have homozygosity frequency consanguineous marriages, marriages between members occurred intense population mixing. Result was birth inter-ethnic/brotherhood (heterozygotes), developed