STING-associated vasculopathy with onset in infancy: the first case in Bulgaria and review of the literature

Abstract

We report a clinical case of a 4-year-and-10-month-old boy whose first symptoms (fever and tachypnoea) were noticed at the age of 6 months. In the upcoming months, skin acral violaceous plaques developed. Failure to thrive and growth impairment were detected. In the journey to find the correct diagnosis, a lot of diseases were suspected. The final diagnosis was suggested after more than 2 years since the first symptoms had appeared. A multi-detector computed tomography of the chest with low radiation dose protocol showed signs of interstitial lung disease (ILD). Next-Generation Sequencing was done, and it revealed a pathogenic heterozygous N154S mutation (NM_198282.4 (Stimulator of IFN genes STING1):c.461A > G (p.Asn154Ser)) in STING1 gene. Treatment with JAK-inhibitor baricitinib was started at the age of 3 years and 10 months. The presence of cutaneous vasculopathy, lung involvement, laboratory signs of inflammation, recurrent fevers and failure to thrive should indicate STING1 gene analysis. STING-associated vasculopathy of infantile-onset (SAVI) is one of the newly identified type I interferonopathies. SAVI is characterized by systemic inflammation via the overproduction of type I IFN due to heterozygous gain-of-function mutations in STING1. The onset of the symptoms of SAVI is usually early in infancy with recurrent fevers accompanied by increased acute phase reactants and ulcerating skin lesions.