The role of X inactivation and cellular mosaicism in women's health and sex-specific diseases.
Sex-specific manifestations of disease are most often attributed to differences in the reproductive apparatus or in life experiences. However, a good deal of sex differences in health issues have their origins in the genes on the sex chromosomes themselves and in X inactivation-the developmental program that equalizes their expression in males and females. Most females are mosaics, having a mixture of cells expressing either their mother's or father's X-linked genes. Often, cell mosaicism is advantageous, ameliorating the deleterious effects of X-linked mutations and contributing to physiological diversity. As a consequence, most X-linked mutations produce male-only diseases. Yet, in some cases the dynamic interactions between cells in mosaic females lead to female-specific disease manifestations.
Migeon
Barbara R
BR
The McKusick-Nathans Institute of Genetic Medicine and Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Md 21205, USA. bmigeon@jhmi.edu
D001327:Autoimmune Diseases / Q000235:genetics; D004198:Disease Susceptibility; D005260:Female; D050172:Genes, X-Linked; D006304:Health Status; D006801:Humans; D009030:Mosaicism; D009154:Mutation; D010641:Phenotype; D012727:Sex Characteristics; D049951:X Chromosome Inactivation