The Genomic Landscape of Pediatric Rheumatology Disorders in the Middle East

Abstract

Abstract: Genetic investigations for patients with pediatric rheumatological disorders have been limited to classic genotyping testing, mainly MEFV hotspot mutation analysis, for periodic fever. Therefore, the landscape and clinical utility of comprehensive genomic investigations for a wider range of pediatric rheumatological disorders have not been fully characterized in the Middle East. Here seventy-one pediatric patients, of diverse Arab origins, were clinically and genetically assessed for a spectrum of rheumatology-related disease at the only dedicated tertiary children’s hospital in the United Arab Emirates. Clinical genomic investigations included mainly (76%) next generation sequencing-based gene panels and whole exome sequencing, along with rapid sequencing in the intensive care unit (ICU) and urgent setting. The overall positive yield was 46.5% (16.7%-66.7% for specific indications), while dual diagnoses were made in 2 cases (3%). Although the majority (21/33, 64%) of positive findings involved the MEFV gene, the remaining (12/33, 36%) alterations were attributed to eleven other genes/loci. Copy number variants contributed substantially (5/33, 15.2%) to the overall diagnostic yield. Sequencing-based testing, specifically rapid sequencing, had high positive rate and delivered timely results. Genetic findings guided clinical management plans and interventions in most cases (27/33, 81.8%). We highlight unique findings and provide additional evidence that heterozygous loss of function of the IFIH1 gene increases susceptibility to recurrent fevers. Our study highlights the importance of comprehensive genomic investigations in patients with pediatric rheumatological disorders, and provides new insights into the pathogenic variation landscape in this group of disorders.