Juvenile arthritis caused by a novel FAMIN (LACC1) mutation in two children with systemic and extended oligoarticular course

Background: the pathophysiological origin of juvenile idiopathic arthritis (jia) is largely unknown. however,individuals with presumably pathogenic mutations in famin have been reported,associating this gene with a rare subtype of this disorder. famin,that is formerly also referred to as lacc1 or c13orf31,has recently been shown to play a crucial role in immune-metabolic functions and is involved in regulation of inflammasome activation and promotion of ros production. case presentation: we describe two siblings with severe familial forms of juvenile arthritis in which whole-exome-sequencing revealed a novel homozygous frameshift mutation (nm_153218.2:c.827delc . p.(t276fs*2) in famin. conclusions: the observation of a new deleterious mutation adds further evidence that pathogenic mutations in famin are causal for a monogenic form of jia. furthermore the associated phenotype is not restricted to systemic jia,but can also be found in other forms of familial juvenile arthritis. © 2016 the author(s).