Retinal Vasculitis in Familial Blau Syndrome.

Blau syndrome is a rare autosomal dominant condition resulting from mutations in the Nucleotide Oligomerization Domain of 2 ;(NOD2) gene. The disease typically presents in early childhood with a triad of arthritis, dermatitis, and uveitis. In this report, we describe retinal vasculitis as a rare phenotype in a family affected by Blau syndrome. Retrospective case series of 3 family members with Blau Syndrome presenting with bilateral retinal vasculitis. The clinical presentation, systemic features, and imaging findings were reviewed. Case I, a 3-year-old boy with childhood-onset of arthritis and uveitis. Ocular manifestations were anterior segment inflammation (2  +  cells), keratic precipitates, posterior synechiae, complicated cataract, perivascular choroiditis scars, and diffuse small vascular leakage on fundus fluorescein angiography (FFA). Case II, cousin of Case I, was a 24-years-old female with childhood-onset arthritis and uveitis. Ocular features were bilateral panuveitis and small vessel leakage on FFA. Case III, sibling of case II had late onset of uveitis at 28 years of age. On examination, he had pigment on the anterior lens surface, vitritis, and small vessel vasculitis in both eyes. However, he did not have any history of arthritis or dermatitis. Bilateral small vessel vasculitis was a common feature observed in all the three cases. Case II and III were paternal cousins of Case I. All patients had a pathogenic variant in NOD2 gene (NOD2: g.18773C>T, c.C>T1000, p.R334W) and were diagnosed with familial Blau syndrome. We report retinal vasculitis as a rare phenotype of Blau syndrome.