Help for a writer

Hi, let me preface my question by preemptively apologizing if my topic is inappropriate amidst other serious issues posted here.

I'm a writer stuck on a certain plot-point which deals with a medical condition that, after months of research, still eludes me.

I need a medical condition for my main character that:

A. Must be treated by a transplant/donation.
B. But, that donor or transplant is rare and generally only family members are a match.
C. Will be terminal within a year if transplant is not received.
D. Will exhibit some physical deterioration.

I appreciate any and all comments or suggestions. Thanks in advance.

[Dr Vinod]

I am feeling quite sorry that i am advicing medical conditions to a writer where the death is imminent. So if it is for knowledge sharing it would be my pleasure to give you advice and i hope you use it for positive knowledge sharing.

For people Blood cancer( Leukaemia) is always interesting and Bone marrow transplant which is given by a family member is a possibility.
The treatment for chronic Myeloid Leukaemia would require an allogenic transplantation. Transplantation from a family donor who is either matched or mismatched at only one HLA locus, is considered normally
All your A,B,C,D points are satisfied for Chronic Myeloid Leukaemia.

Take care and use it for positive information sharing.