The next day he was called into the haematology department of his hospital and a doctor broke the news that he had myeloid dysplasia, a blood disorder which is a precursor to leukaemia.

The news was a terrible shock for Gary and his family, but since learning about his condition he is positive that help might come from a bone marrow transplant.

His condition has now developed into acute myeloid leukaemia and he has been told that after undergoing a course of chemotherapy to kill off the leukaemia cells, he will need a bone marrow transplant in the next two to three months, which will give him the best chance of a full recovery.

Gary's friends, who live in Petworth and Bosham, have rallied round and with the help of the Anthony Nolan Trust, which is in charge of the bone marrow donor register, have organised a potential donor session at Bosham Sailing Club and are urging as many people as possible to come forward to give the gift of life.

Gary, (45), who was a former company director at Chichester Festival Theatre, said: "I am currently just starting my second and hopefully final round of chemo at Kings College Hospital in South London, but currently haven't found a bone marrow donor.

"Without finding an adult donor my long-term prognosis is not good. There is a new, fairly experimental treatment using stem cells from donated umbilical cords.

"While this is a better option than no transplant at all, there is scant research on how effective this procedure is in the long term.
"As of last week we have been unable to find a match for me on the worldwide register but I'm hoping that someone in the Chichester area might be a match for me."

Friend Mandy Oldfield said joining the register was an extremely important thing for people to do.

"Gary's had so much support. He's got a great network around him and he's being very positive. When we first heard about it we were all terribly shocked, but we started talking about the Anthony Nolan Trust and got onto the website.

"We were all thinking along the same lines and decided that we'd like to organise a donor register session.

"They are incredibly important. There is a one-in-a-billion chance of a match, so it's vitally important for people to register. The more people who register, the more chance of finding a match. Without it we don't want to think about the consequences."

The donor register session takes place on Wednesday, January 16, from 5pm until 8pm, at Bosham Sailing Club.

Donors need to be aged 18 to 40 and in very good health. You need to fill in a form and have a blood test before you are included on the register.

Despite living in London now, Gary still has very close links with the area.

His eldest son was born at St Richard's Hospital and he has two children aged under two.

He believes even if potential donors aren't able to help him in the end, joining the register is still an important way of helping others.

"Obviously it would be wonderful if someone from Chichester were a match for me," Gary said.

"But my feeling is that even if I don't get a match, everyone who registers has a chance to save someone's life – someone's son, daughter, mother, father or partner – for comparatively little effort. How wonderful would that be?"

WHY IS BONE MARROW IMPORTANT?
Bone marrow is very important as it helps the body to produce red blood cells which carry oxygen around the body, help prevent bleeding and fight off infection.

Some illnesses directly attack the red blood cells, in others the chemotherapy used to kill the cancer cells also destroys the patient's bone marrow.

The cells can be collected from bone marrow or from the blood which circulates around the body – these are known as peripheral blood stem cells.

THE TRANSPLANT
Bone marrow transplants are different from organ transplants. Bone marrow and peripheral blood stem cells are both removed by needle and received intravenously.

The bone marrow donation requires a two-night stay at a specialist hospital in London to undergo a medical procedure called a harvest. The donor is put under general anaesthetic and the blood stem cells are extracted from the pelvic bones by needle and syringe. The blood stem cells then replace themselves within 21 days.

Peripheral blood stem cells are collected by injecting a growth factor, which occurs naturally in the body, five days before cell collection. This temporarily boosts production and encourages the cells to move from the bone marrow where they are made out into the circulating blood. The cells are then collected via a sustained needle on a blood cell separator machine, in a process called apheresis. One or two collections on consecutive days, each lasting around four to five hours, may be required, but overnight hospitalisation is not usually necessary and no general anaesthetic is needed.

WHO CAN DONATE?
Anyone in excellent health aged 18-40. Your details remain on file until you are 60.

In particular the Anthony Nolan Trust needs people who are male and/or from an ethnic minority in the UK or of mixed ethnic background, as they are under-represented on the register.

Donors need to weigh at least 8st (51 kgs) and live permanently in the UK (and likely to be living here for the next two to three years).

Donors also need to ensure they stay in touch with the trust and give further blood samples if needed.

A person could be the only match in the world for someone else.

Family members (siblings in particular) offer the closest matches, but 70 per cent of patients do not have a suitable sibling so a match has to be found elsewhere.

Bone marrow registers are kept in different countries.

Volunteer donors have to fill in a form, then give a small blood sample which is then analysed and a record kept of your tissue type. A patient's tissue type is then entered onto a computer and checked against every donor tissue type listed.

THE ANTHONY NOLAN TRUST
The trust was started in 1974 by Shirley Nolan to try to save the life of her son Anthony who was suffering from an immune deficiency disease.

He died five years later, aged seven, without a matching donor being found. Shirley Nolan passed away in 2002.

The trust now manages the world's first and one of the largest fully-independent registers of potential blood stem cell donors.

There are more than a third of a million volunteers on the register and the trust receives more than 6,000 new requests each year to search for donor matches.

WHERE IS THE DONATION SESSION?
Wednesday, January 16 at Bosham Sailing Club, The Quay from 5pm until 8pm. 01243 572341.

For more information about joining the register, contact the Anthony Nolan Trust on 0901 88 22 234 or see www.anthonynolan.org.uk