Posted by Carla Mackenzie
April 14, 2011
A girl’s genetic makeup dictates the age at which she has her first period, new research has revealed.
The study of almost 26,000 women in the UK showed that the age at which a female starts menstruating is known to run in families, but the researchers wanted to establish whether environmental factors had a bearing as well.
Scientists from the UK’s Institute of Cancer Research analysed data from the women, all of whom had at least one other female relative taking part in the study.
The researchers found that the age at which a woman began her periods was linked with that of her relatives.
Genetic factors were found to account for 57 per cent of the variations in the ages of menarche seen in the study.
“Our study findings suggest that genetic factors have a major influence on the age women in the UK begin menstruating, and these could have an impact on breast cancer risk,” said lead author Danielle Morris, from the institute.