Common cause of hysterectomy linked to genetic mutation

Researchers in Finland have discovered a genetic mutation potentially involved in the formation of uterine fibroids. Fibroids are the most common reason for hysterectomy, and 60 percent of women develop them before the age of 45.

Fibroids, or uterine leiomyomas, are benign tumours of the uterus that can cause symptoms such as pelvic pain, heavy menstrual bleeding and frequent urination, and can even lead to infertility. Despite their clinical importance, very little is known about the mechanism of fibroid formation. Previous work had implicated several genetic mutations, but only in a minority of cases.

In a process known as exome sequencing scientists from the University of Helsinki compared all the protein-coding genes in 18 fibroids from 17 patients with those in normal tissues. They identified a genetic mutation in the MED12 gene in ten fibroids. The protein product is involved in gene regulation, and after analysis of a further 207 fibroids the researchers determined that 70 percent of the tumours contained this mutation.

As such a large proportion of the fibroids had the mutation the findings are hoped to aid in the development of treatments in the future.

Dr Elizabeth Stewart, who researches fibroids at the Mayo Clinic in Minnesota, USA, and was not involved in this study, said: 'If we can understand what the critical steps are in creating the fibroids, that may open up novel treatment mechanisms'.

Lead researcher Dr Lauri Aaltonen has suggested that the mutation may cause changes in the way genes are expressed in the smooth muscle of the uterus. However, the team acknowledges that further work is required to determine exactly how it drives tumour formation and how it can be used in clinical practice.

Dr Aaltonen said: 'This is a giant step towards understanding why fibroids arise, but towards design of targeted therapies it is an early step. Let's hope the journey has begun'.

Dr Stewart also warned that since the samples in the study were from one hospital in Helsinki a wider demographic of women should also be investigated, especially as women of African descent are more likely to get uterine fibroids.