Friday 20 October 2017

Why?

In life, we ask lots of questions. Why is the sky blue? What came first, the chicken or the egg? If a tree falls in the forest and there is nobody there to hear it, does it still make a noise? Thanks to science we have learnt the answers to many of life’s conundrums. However, sometimes we are just left with multiple theories and it is up to us to choose which we believe, if any. I was and will always be the first female in the world to be diagnosed with Norrie’s Disease. But for as long as I can remember I have asked myself and the professionals why did this happen to me? How can a condition that is only supposed to affect males been passed on to me? Why wasn’t I born totally blind like my male family members with the condition? Over the years I have heard numerous theories, but nobody seemed interested in finding out the real reason other than me.

It has taken over a year of referrals and appointments, but I finally have some answers. It has been a few years now since I came to terms with losing my sight, yet I can honestly say I have never come to terms with having Norrie’s Disease itself. Until now that is. A part of me was convinced that I had a different condition despite my family history and Norrie like symptoms. Whilst I have always claimed to have Norrie’s Disease I have often felt like a fraud when communicating with others about the condition, especially when people have asked how I have it and I never had any firm facts.

Scientifically speaking, female carriers of Norrie’s Disease have a one in four chance of having a child affected by Norrie’s Disease. Technically, if the child is a boy there is a 50% chance that they will present with the condition and if a girl there is a 50% chance that they will be a carrier of the condition. This is because Norrie’s Disease is an X-linked condition. Theoretically, a female should not present with symptoms of the condition as they have two X chromosomes and therefore should activate the Norrie gene on the spare chromosome. Males present with the condition because they only have one X chromosome.

When I began to present with symptoms of Norrie’s Disease at the age of two, I did undergo genetic testing. However, at that time they did not know the location of the Norrie gene nor did they have the ability to test for the reason why I have the condition. Without my knowledge my blood sample was re-tested in 2004 due to the advancements in technology. I only received the results in August at an appointment that I fought tooth and nail for. The tests revealed that I have a mutation on the Norrie gene confirming that I am definitely a carrier of Norrie’s Disease. Although I have always suspected this was the case, it was quite gutting to hear that I could potentially pass Norrie’s Disease on to my children. The results also indicated that I most likely had skewed X inactivation syndrome.

They took more blood on the day from myself and my mum in order to run further tests. I received the results last week, which stated I have significant skewed X inactivation meaning I activated more genes on my maternal X one of course being the mutated Norrie gene. Thus explaining why I have Norrie’s Disease. At some point after conception, females activate genes on their X chromosomes. Normally, they activate approximately 50% on each. For whatever reason, I chose to activate more of my mum’s genes. She has always joked when I was born she thought she had cloned me because my appearance was so alike to hers! Lots of females might have skewed X inactivation, but not know about it since they haven’t activated a faulty gene.

It is so good to have some proper answers. I know it doesn’t change the fact that I have Norrie’s Disease and it can’t bring back my sight. If anything it has unleashed a new can of worms as I know I’m a carrier of the condition and know I am set on having children. Nevertheless, it has given me closure. I can confidently say I have Norrie’s Disease and I now know why.