Hyperestrogenic syndrome is a chromosomal disorder in which the karyotype of a normal female is 46XX, while in hyperestrogenic syndrome, there is an extra X chromosome and the karyotype is 47XXX. They may also have a wide eye spacing, a wide breast spacing, a small head, etc. They may have mild developmental delays, learning difficulties, and generally mild intellectual impairment. In the reproductive system, the impact on fertility is not significant, but the incidence of infertility is higher, often with reduced menstruation, secondary amenorrhea and premature ovarian failure.