BBC News NI previously reported on concerns that not enough people were being tested for it in Northern Ireland because of the cost.

The Department of Health’s current policy is to screen for genetic haemochromatosis when a patient shows symptoms.

But a charity has said it is hoping to capture more information on areas of Northern Ireland where people may be undiagnosed.

Haemochromatosis UK will offer up to 23,500 households free genetic screening in Irvinestown, Portadown, Ballymena and Magherafelt.

Neil Irwin works for Haemochromatosis UK and was diagnosed with the condition seven years ago.

He says early diagnosis is key to allow people access to effective treatments.

“In recent years we have had anecdotal evidence from areas like Mid Ulster where people have been contacting us saying their area seems to have high rates of haemochromatosis,” he said.

“But there is a lack of official data, so we’re looking to fill in some of those blank spots in Northern Ireland that have never screened before, to paint a more detailed picture of the prevalence of the condition.”