"Being refused a scan for a high-risk condition in my family"

I have been refused a test which may save my life. Why? Good question, one I would love to know.

My family has a history of subarachnoid haemorrhage, my aunt suffered one five years ago and as my great nan died of the same condition my family was told by her consultant to have a scan to check if anyone else was at risk.

First my three cousins were scanned by Southend hospital, later my mother got her scan - she had a an ophtalmic aneurysm which needed surgery quickly to save her life as this aneurysm is very serious and she would not live long.

Later 3 other members of the family have been confirmed with this problem.

Now Southend hospital refuses to test me because I don't have 2 first family members with the problem but they did scan my cousins who have the same family members as me! And they got the test with only one first degree family which is the same as me!

I am an only child, so I will not have the chance of having two first degree relatives having this problem. Why am I being refused?