Primary visceral myopathy caused by a pathogenic mutation in the gene encoding the enteric smooth muscle actin gamma 2 ( ACTG2) affects gastrointestinal and genitourinary tracts and often presents as chronic intestinal pseudoobstruction. We present a case of pediatric onset chronic intestinal pseudoobstruction associated with a novel missense ACTG2 mutation c.439G>T/p.G147C. In addition to the known disease manifestations of feeding intolerance and intestinal malrotation, our patient had a late-onset hypertrophic pyloric stenosis and a late-onset choledochal cyst, the former of which has not previously been described in patients with ACTG2-associated visceral myopathy.

Most human autoimmune diseases have a relapsing-remitting or a chronic progressive course, while animal models are usually acute and monophasic. In our experimental animal model the disease can be either monophasic or remitting, depending on the autoantigen used for induction, and it appears to lie in the effector phenotype of the elicited T helper cell response. Since both, monophasic and relapsing courses of disease are induced by immunization as well as by adoptive transfer of peptide-specific, CD4(+) T cells, we were able to directly compare the transcriptomes of pathogenic T cell lines by gene array analysis and qPCR as well as protein expression. Upregulated genes were only determined in T cells inducing relapsing uveitis and belong to certain pathways of antigen presentation, activation, inflammation, migration and survival, comprising WNT, Hedgehog, MAP-kinase and JAK/STAT-pathways. These pathways are partially interacting with each other, and the central molecule upregulated in T cells causing relapsing disease was found to be IFN-γ. Here the course of the autoimmune diseases strictly depends on the characteristics of the autoreactive T cells, which are already determined at their early stage of antigen-specific activation. Our rat models of experimental autoimmune uveitis could help elucidating the immune mechanisms behind relapsing autoimmunity in order to develop better therapeutic strategies.