Asperger's with very new OCD type behaviour

Afternoon all.  First post, so please be gentle....

My 15 year old son has Noonan's, Aspergers (with associated ADHD) and many associated issues diagnosed (for instance sleep issues or dyspraxia). We are used to new behaviour but this one has us stumped and concerned.

Since a Parent's evening on tuesday, my son has been exhibiting what to us can only be described as OCD type behaviour both at school and around the house.  The behaviour is 'extreme tidyness' especially in his bedroom - everything doesn't necessarily have to be put away, but it all needs to be square in relation to the table, desk, floor, other piles or items and other furniture. He's even tidied up his wardrobe (into relevant piles) for the first time in 15 years without us asking. At school he has to have space, and pens, pencils, calculator etc have to be square on the desk. Books have to be in size order, with one corner being squared off.  The behaviour started on Wednesday morning, hasn't been seen before except for one instance, and literally he's gone from one state to another (messy to tidy) overnight.

We were wondering if anyone had come across such behaviour before?  We think it's anxiety induced due to the parents evening, but he won't say why.

Ta very muchly

Kev