DEAR DR. DONOHUE: Our two sons, in their 50s (we’re in our 80s) have both been diagnosed with the blood disorder factor V Leiden.

One of them had a blood clot in his leg. His doctor says it is hereditary. Should they and we be concerned? – T.V.

ANSWER: If we didn’t form clots, we could die from a small injury. The process of clot formation is complicated.

It requires platelets, the smallest blood cells, along with blood proteins called clotting factors.

Clots can also cause big trouble when they form when they shouldn’t. To prevent inappropriate clot formation, the body has mechanisms to turn off clotting.

Factor V (Roman numeral 5) is one of our clotting factors. Factor V Leiden (Leiden is the city in the Netherlands where the discovery of this factor was made) is a genetically caused change in normal factor V. The mechanism to turn off inappropriate clot formation doesn’t work well when people have this mutant factor — they form clots when they shouldn’t.

The seriousness of the condition depends on having only one gene or two genes for the factor.

Two genes put a person at great risk of having a dangerous clot; one gene, a lesser risk.

Your sons most likely have only one factor V Leiden gene. If either should form a clot, they have to stay on blood thinners longer than other people do.

If they form a second clot, they might have to stay on blood thinners for life.

You and your wife are in your 80s and have not had any clot troubles thus far. One of you must carry the Leiden gene. You don’t have to stew about this, but you should mention it to your doctor so the doctor can act appropriately if either of you happens to form an inappropriate clot.

That’s the extent of your concern.

DEAR DR. DONOHUE: I am a 57-year-old male in good health. I do not drink or smoke and I watch my diet.

In 1969, I became a hepatitis B carrier.

In the early ’80s, my blood count changed for the better. I have my blood checked regularly.

The last results were good. My question is: Are there any new studies about curing hepatitis B carriers, or is there a shot to prevent people from becoming hepatitis B carriers? – P.G.

ANSWER: Hepatitis B can be treated successfully, but not always.

However, you might not need treatment. I take “blood” tests to mean liver tests.

If liver tests are normal and if there is not a high level of virus in your blood, then observation is the recommended treatment for a carrier. At times, a liver biopsy provides information that heavily influences the decision to treat or withhold treatment.

Medicines for hepatitis B are entecavir, adefovir, lamivudine and interferon alpha. The newest medicine is telbivudine.

Yes, there is a shot to prevent hepatitis B infection and, therefore, the carrier state. It’s the hepatitis B vaccine.

People should ask their doctors if they are candidates for this vaccine.

The hepatitis story – A, B and C – is told in the booklet on that subject. Readers can order a copy by writing: Dr. Donohue – No. 503, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6.75 Can. with the recipient’s printed name and address.

Please allow four weeks for delivery.

DEAR DR. DONOHUE: Would you shed some light on the illness that caused my father’s death at age 75 in 1950? It was cryoglobular anemia. I know “cryo” means “cold” and “globular” refers to a round shape.

I wonder if today there would have been treatment for him. – V.C.

ANSWER: You’re right. “Cryo” means “cold.” “Emia” stands for “blood.”

Globulins are large proteins, antibodies like gamma globulin. The full name is cryoglobulinemia.

In that illness, globulin proteins solidify when exposed to cold. The illness was first described in 1947, so there wasn’t much information available when your dad was diagnosed with it.

Often there’s another illness that spawns cryoglobulinemia.Some infections (hepatitis C, for example), blood vessel inflammation (vasculitis), connective tissue diseases (lupus) and kidney failure are some of those conditions.

Today, prednisone, cleansing the blood of cryoglobulins (plasmapheresis), chemotherapy and drugs that suppress antibody formation are some of the treatments for it.

DEAR DR. DONOHUE: What is your opinion on “colon cleansing” products? Are they really necessary? – J.C.

ANSWER: I don’t believe in colon cleansing. Undigested food is not a poison. The colon was given innate mechanisms to protect itself.

There’s no need to use enemas or laxatives to keep the colon “clean.”

There are reasons for which enemas and laxatives are necessary, but cleaning the colon is not one of them.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475.

Readers may also order health newsletters from www.rbmamall.com.