Hello Jack,
Myelodysplastic syndromes are a group of disorders affecting the bone marrow.
They are not types of cancer, although in a small number of people they can
develop into a particular form of leukaemia

Most cases of myelodysplasia have no known cause and are called primary
myelodysplastic syndrome.

In a small number of people, a myelodysplastic syndrome occurs as a result of
previous treatment with either chemotherapy or radiotherapy. This is known as
therapy-related or secondary myelodysplastic syndrome.

The myelodysplastic syndromes are more common in elderly people but can occur
at any age.

You might want to try HEM-ONC list here http://www.acor.org/mailing.html?l=h
(click on it, then "join". Select digest mode. You'll be advised when you can
start sending messages).
If they know of a different /better support list, they'll advise you.
Best wishes,
J