DEAR DR. DONOHUE: I am looking for information on Zollinger-Ellison syndrome, particularly concerning heredity. A relative died from this disease some years ago. – J.R.

ANSWER: Zollinger-Ellison syndrome is responsible for a unique kind of ulcer. The ulcer, found most frequently in the duodenum (the first part of the small intestine) or less frequently in the stomach, results from a tumor that makes gastrin. Gastrin is a hormonelike material that stimulates stomach acid production. The excessive amounts of stomach acid erode the lining of the digestive tract and create an open sore – an ulcer.

The tumor is often found in the pancreas.

A ZE ulcer produces the same kind of stomach pain that comes from an ordinary ulcer. Heartburn and diarrhea, two symptoms not usually associated with an ulcer, are regularly part of the ZE ulcer picture.

If a surgeon can remove the entire tumor, then the symptoms usually end quickly. If, on the other hand, the tumor has spread to a distant location such as the liver, the outlook is less optimistic. Medical treatment of a ZE ulcer includes the same kind of medicines used for an ordinary ulcer, but the dose of medicine must often be increased and the time of treatment prolonged.

For nearly 75 percent of ZE patients, heredity does not have a great influence. For the remaining 25 percent it does. For those people, ZE syndrome is part of a bigger picture. Those people have associated tumors of the pituitary gland, the parathyroid gland and the insulin-producing cells of the pancreas. If a person has this kind of ZE syndrome, his or her children have a 50 percent chance of coming down with the same problem later in life.

DEAR DR. DONOHUE: My only granddaughter, 5 months old, has a hip joint problem called hip dysplasia. She is in a cast. Is this a genetic problem? I wonder how immobilizing the hip helps. – V.H.

ANSWER: The hip joint is a ball-and-socket joint much like the shoulder joint. The ball is on the top of the femur – the thigh bone. The socket is in the pelvic bone. The arrangement gives a hip great latitude of movement..

Hip dysplasia is a faulty development of hip joint cartilage together with lax hip ligaments. The ball part of the hip joint pops out of the socket. The hip is dislocated.

The dysplasia is partly due to genes, partly due to an abnormal position of the legs during fetal development and partly due to an inborn looseness of hip ligaments.

The hip joint usually rights itself after the baby is put into a harness, a splint or a cast. Ligaments tighten, and the ball fits more snugly in the socket. After treatment, most children have a normal hip. A few, however, come down with avascular necrosis. Here, the blood supply to the hip slackens and the bone crumbles. Treatment for avascular necrosis differs from the treatment of hip dysplasia.

DEAR DR. DONOHUE: Several years ago I fell hard on my bottom and broke off my tailbone. I have trouble sitting comfortably. And now the broken part moves around, and I can feel it poke me. Could it do any damage to blood vessels or the intestines or the skin? – M.R.

ANSWER: The tailbone, the coccyx (KOK-six), is a small, bony appendage attached to the bottom of the spinal column. It consists of fused, rudimentary vertebrae (backbones).

A fall can fracture the bone and make sitting uncomfortable. Slouching makes sitting even more uncomfortable.

Sitting in a few inches of warm water in a tub often brings pain relief. Using a doughnut-shaped pillow eases the pain of sitting. Encircling the hips at midbuttock level with a 3-inch-wide belt forms a natural cushion and protection for a painful, fractured coccyx.

I have never heard of a piece of the coccyx migrating from its normal position to a position where it could endanger blood vessels, intestines or skin. But an X-ray will definitely answer your question.

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.