Poretti-Boltshauser syndrome diagnosis for Wallsend girl

Addison Black is "thriving", her parents say

The parents of a child have said it was a "bolt from the blue" to discover she was only the 30th person in the world to be diagnosed with a rare condition.

Addison Black was diagnosed about two years ago with the brain disorder Joubert syndrome.

But brain sequencing by experts at Newcastle University has now found the five-year-old's special needs were due to Poretti-Boltshauser syndrome.

Mum Carli Black, of Wallsend, said they were pleased it was a milder condition.

She said it was obvious from a young age that something was not right with their daughter's development.

'Heart breaking'

Addison was not hitting various milestones, could not make eye contact and could not walk until the age of three.

"When we were given the initial diagnosis of Joubert syndrome it was heart breaking," she said.

"We were told it was life-limiting, there would be ongoing problems with her kidneys, eyesight, lots of children end up having secondary illnesses, pneumonia and things like that.

"It was horrendous, you should not expect to have to out-live your children."

Addison, pictured here with her mother and brother Cody, enjoys school

About two years after the diagnosis, Addison, mum and dad Stewart attended a specialist clinic in Newcastle where experts analysed families with possible genetic causes of brain abnormalities.

Addison's diagnosis was then changed to the new, and much rarer syndrome, Poretti-Boltshauser.

This also causes delayed brain function and speech problems but does not lead to kidney failure and other life-threatening complications associated with disorders such as Joubert syndrome.

Professor Eugen Boltshauser, a retired children's brain specialist whom the syndrome is named after, was also involved to help ensure a correct clinical diagnosis as it is so rare.

'Over the moon'

Professor John Sayer, deputy dean of clinical medicine at Newcastle University, said: "Our study ... is important because it allows patients with rare brain disorders a much better chance of a correct clinical and genetic diagnosis.

"This will help many families to get more precise information about their child's condition and know in much clearer terms what the future will hold."

Mrs Black said: "To be told after genetic screening that Addison had a different condition came as a bolt out of the blue as we didn't expect it and we had never heard of Poretti-Boltshauser syndrome.

"It's so rare, Addison is only the 30th person in the world to have this new syndrome and there's very little known about it.

"But obviously we are now thrilled and over the moon that we are not living every day as if it can be her last.

"It also means that we can speak to the few other families in a similar situation and learn from one another's experiences, which is so important in our understanding of Addison's complex needs."

The family is thrilled they have clarity over the new diagnosis