Reproductive function in women is closely linked to factors such as nutrition, neuroendocrine signals and genetics. It is known that gene-environment interaction can influence the premature onset of menarche.
Menarche
Menarche is the name given to the first menstruation in women. It typically occurs about two years after the appearance of pubic hair and incipient breasts, and can occur prematurely before the age of 8 or delayed until the age of 16.
The first menstruation symbolizes a state of maturity characterized by the preparation of the young woman's body for reproduction and greater clarity as to sexual identity.
Menstruation or period is the normal vaginal bleeding that occurs as part of a woman's monthly cycle. Every month, her body prepares for a possible pregnancy. If this does not occur, the uterus sheds its lining (endometrium), which is shed with menstrual bleeding, and is renewed in the next cycle.
Daughters of mothers with an early age of menarche are more likely to have an early onset of menarche.

Number of observed variants
13.5 million variants
Number of loci analyzed
147 loci
Genes analyzed