Turner's syndrome (the syndrome of gonadal dysgenesis) is the most common form of primary gonadal failure associated with a female phenotype (Fig. 13.26). The 45X karyotype occurs in one out of fifteen spontaneous abortions; 99.9% of 45X foetuses do not survive to twenty-eight weeks of gestation; the incidence of Turner's syndrome is between 1:2,000 and 1:5,000 live phenotypic female births.
