The following is a summary of “Molecular diagnostic yield for Blau syndrome in previously diagnosed juvenile idiopathic arthritis with uveitis or cutaneous lesions,” published in the November 2023 issue of Rheumatology by Zhong et al.
Juvenile idiopathic arthritis (JIA) and Blau syndrome are similar immune-related disorders that can be difficult to diagnose, especially in the community. The effectiveness of next-generation sequencing (NGS) in diagnosing these disorders across diverse populations remains uncertain.
Researchers performed a retrospective study to assess the utility of NGS for diagnosing JIA and Blau syndrome in different populations.
The study assessed the clinical utility of targeted next-generation sequencing in individuals previously diagnosed with JIA who exhibited symptoms and signs indicative of Blau syndrome, such as uveitis or skin lesions in addition to arthritis. Targeted sequencing of the NOD2 gene was performed to identify pathogenic or likely pathogenic variants associated with Blau syndrome. They aimed to evaluate the diagnostic yield and the impact on patient care.
The study collected sequencing data from 123 previously diagnosed JIA patients (median age: 5 years; female: 62.6%). Targeted NOD2 sequencing revealed a positive molecular diagnosis of Blau syndrome in 21.1% (95% CI, 14.9%-29.2%), including six heterozygous missense mutations classified as pathogenic variants and among those with a molecular diagnosis, clinical management, and treatment changes occurred in 38.5%. About 9 predictors associated with a higher diagnostic yield were identified, providing clinical insights for suspecting Blau syndrome.
The study found that targeted NOD2 sequencing identified Blau syndrome in nearly one in five patients with pediatric-onset arthritis, uveitis, or cutaneous lesions, providing clinically relevant information for patient care.
