CHEK2 genetic mutation might increase cancer risk

DEAR DR. ROACH: My almost-42year-old daughter was informed today by her gynecologist that she has two CHEK2 genetic mutations. She has always been healthy. She and her husband have three young children, so my daughter is rather concerned.

This revelation came during an otherwise routine visit with her gynecologist. Do you have any statistics on how many women with this genetic mutation actually develop breast or colon cancer?

— B.R.H. ANSWER: CHEK2 is a gene that makes a protein called checkpoint kinase 2, which is a DNA-repair protein. If that protein doesn’t work properly when a genetic mutation occurs, people can be at higher risk for developing cancers. Only a few mutations are known to be associated with an increased risk of breast or colon cancers.

I looked up the mutations you sent me, and they are both listed under “uncertain significance,” meaning that there may be a risk associated with them, but as of yet, it is unproven. In one mutation known to increase risk (one that your daughter does not have), the lifetime risk of breast cancer is about 32%; whereas in women without the mutation, the risk is about 13%.

Similarly, those with the most dangerously known CHEK2 mutations have an increased lifetime risk of colon cancer of about 12%, compared with the risk in the general population of about 6%. It is likely that her additional risk, if any, will be much less than the risk of this known dangerous mutation.

Her genetic counselors will have more information about the exact nature of her mutations.

Because of the lack of exact knowledge about how dangerous the mutations are, your daughter will likely be recommended to have breast exams and mammograms at an earlier age and at a greater frequency than a woman at average risk, and possibly a colonoscopy earlier as well.

DEAR DR. ROACH: Our 50-year-old son developed Meniere’s Disease and has since lost all the hearing in his right ear. He continues to deal with dizziness, and has been told by his doctors that there is nothing that can be done “until someone famous gets this, and more research is done.”

He has tried one hearing aid, but that was not satisfactory. This disease affects him greatly in communicating with others, and in his sales position. He finds both the hearing loss and vertigo distressing. Are there any avenues he can take?

ANSWER: Meniere’s disease causes hearing loss, tinnitus (an abnormal sound, usually described as a ringing or buzzing noise in the ear) and vertigo. Pathologically, the organs of balance and hearing in the inner ear are swollen with fluid, but exactly what causes this swelling is unknown.

The hearing loss in Meniere’s disease initially starts in low frequency, which is a major clue into the diagnosis.

Despite treatment, hearing loss can sometimes be progressive and total, which unfortunately sounds like the situation your son is in. Hearing aids are not likely to be effective with such profound hearing loss. I am sorry, but I don’t know of any treatment that is effective in people with complete hearing loss due to Meniere’s disease. However, the vertigo can often be successfully treated with therapies to damage the affected organ of balance, such as gentamycin injected into the inner ear, which relieves symptoms in 80% to 90% of patients.

I am sure that scientists are working to find new treatments.