Explainer: What is amyloidosis, the rare genetic disease Martin McGuinness died from
The disease was first diagnosed in an Irish family in 1986
FORMER Deputy First Minister of Northern Ireland Martin McGuinness died following a short battle with a rare genetic disease called amyloidosis.
Mr McGuinness, who was 66, died during the night at Derry's Altnagelvin Hospital with his family by his side.
He was diagnosed with amyloidosis in December, a disease which has links to Donegal.
What is amyloidosis?
Amyloidosis is a group of rare conditions caused by deposits of abnormal protein - amyloid - in tissues and organs throughout the body.
Without treatment, it can lead to organ failure and death.
What causes it?
Proteins normally start as a strip of amino acids that fold into 3D shapes. However, in amyloidosis, the protein folding goes wrong and they end up getting bunched together.
They are then unable to breakdown, resulting in a build-up of tissue in the organs which gradually leads to organ failure.
A similar system is involved in the development of Alzheimer's - which sees a build-up of amyloid in the brain.
Do many Irish people suffer from it?
No, amyloidosis is very rare. However, a number of cases have been linked to Donegal.
Martin McGuinness was from Derry, but his mother came from Buncrana in Donegal.
A 1995 study found that nearly all those affected were descended from a person called Conall Gulban, after whom Donegal was named.
Up to 1pc of the population in Donegal are said to carry the gene.
What are the symptoms?
Amyloidosis is a difficult disease to diagnose, and it has often been mistaken for heart disease.
The most common symptoms include kidney failure, with a person experiencing poor fluid retention, tiredness and a loss of appetite
Other symptoms include feeling faint, numbness in the hands and feet, chest pain, an enlarged tongue and diarrohea.
How is it treated/cured?
There is currently no cure for the disease.
No treatments can directly remove the amyloid deposits, but treatments are used to prevent a further build-up of proteins.
Chemotherapy can be used and sometimes, the person suffering from the disease will have to have a kidney transplant.