Women who have multiple sclerosis are more likely to carry a gene linked to the illness than men who have the condition, a study has shown.
The findings of the research, which analysed the DNA of more than 7,000 people, found women were also more likely to pass on the gene to female relatives.
Experts said the results helped explain why MS affects as many as three times more women than men.
The study, funded by the MS Society and led by Professor George Ebers at Oxford University, was published in the journal Neurology.
The paper's authors said around the same number of men and women had MS in the 1950s but since then, the ratio of women to men has gone up to 3:1 in Scotland.
Of the 10,000 people living with MS in Scotland, around 6,500 of them are women, according to the MS Society.