Turner Syndrome: Genotype and Phenotype

Turner syndrome (TS) is a sporadic disorder affecting ~ 1/2500 live female births, caused by the absence of all or significant parts of one sex-chromosome. Developmental consequences include severe short stature, ovarian failure and distinctive cognitive and behavioral traits, sometimes with renal and cardiovascular defects. Adults with TS have excessive rates of osteoporosis, hypertension and diabetes mellitus, and high rates of morbidity and mortality. This study aims to correlate TS phenotypes and genotypes, to identify X-chromosome genes and epigenetic mechanisms causing the different features of TS. For TS subjects with a 45X genotype, the parental origin of the single normal X-chromosome will be traced. X chromosomal structural defects will be analyzed in relation to data from the Human Genome Project. The elucidation of genetic mechanisms in TS will help improve the diagnosis and treatment of girls and women with this disorder and further our understanding of gene dosage effects in general.