FCAS2 an autoinflammatory condition caused by a mutation in the NLRP12 gene at the 19th chromosome at position 13.42. It is extremely rare with only 26 reported cases globally. It was only discovered in 2009.
The disease can only be properly diagnosed with genetic testing.
The centre’s of excellence for FCAS2 in the UK are the National Amyloidosis Centre at the Royal Free Hospital in London for adults and Great Ormond Street Hospital in London for children.
There are probably many more cases which are still undiagnosed. For more information, please start here.