Identification of rare coding variants associated with Kawasaki disease by whole exome sequencing

Kawasaki disease (KD) is an acute pediatric vasculitis that affects genetically susceptible infants and children. To identify coding variants that influence susceptibility to KD, we conducted whole exome sequencing of 159 patients with KD and 902 controls, and performed a replication study in an independent 586 cases and 732 controls. We identified five rare coding variants in five genes (FCRLA, PTGER4, IL17F, CARD11, and SIGLEC10) associated with KD (odds ratio [OR], 1.18–4.41; p = 0.0027–0.031). We also performed association analysis in 26 KD patients with coronary artery aneurysms (CAAs; diameter > 5 mm) and 124 patients without CAAs (diameter < 3 mm), and identified another five rare coding variants in five genes (FGFR4, IL31RA, FNDC1, MMP8, and FOXN1), which may be associated with CAA (OR, 3.89–37.3; p = 0.0058–0.0261). These results provide insights into new candidate genes and genetic variants potentially involved in the development of KD and CAA.

Cardiac outcomes in severe acute respiratory syndrome coronavirus-2-associated multisystem inflammatory syndrome at a tertiary paediatric hospital

Introduction: We describe a cohort of children referred with multisystem inflammatory syndrome in children associated with severe acute respiratory syndrome coronavirus 2 and compare this cohort with a 2019 cohort of children with Kawasaki disease. Methods: We conducted a retrospective cohort study of 2019 and 2020 referrals to the inflammatory cardiology service at Great Ormond Street Hospital for Children. We compared cardiac and inflammatory parameters of a sub-section of the 2020 cohort who presented with reduced left ventricular ejection fraction with the remainder of the cohort. Results: Referrals significantly increased between February and June 2020 compared to 2019 (19.8/30 days versus 3.9/30 days). Frequency of coronary artery aneurysms (11/79 (13.9%) versus 7/47 (14.9%)) or severe coronary artery aneurysms (6/79 (7.6%) versus 3/47 (6.4%)) was similar between 2020 and 2019, respectively. The 2020 cohort was older (median age 9.07 years versus 2.38 years), more likely to be of Black, Asian, or other minority ethnic group (60/76 (78.9%) versus 25/42 (59.5%)), and more likely to require inotropic support (22 (27.5%) versus 0 (0%)). Even children with significantly reduced left ventricular ejection fraction demonstrated complete recovery of cardiac function within 10 days (mean 5.25 days ± 2.7). Discussion: We observed complete recovery of myocardial dysfunction and an overall low rate of permanent coronary sequelae, indicating that the majority of children with multisystem inflammatory syndrome in children are unlikely to encounter long-term cardiac morbidity. Although the frequency of myocardial dysfunction and inotropic support requirement is not consistent with a diagnosis of Kawasaki disease, the frequency of coronary artery abnormalities and severe coronary artery abnormalities suggests a degree of phenotypic overlap.

Prediction of Coronary Artery Aneurysms in Children With Kawasaki Disease Before Starting Initial Treatment

Background: Precisely predicting coronary artery aneurysms (CAAs) remains a clinical challenge. We aimed to investigate whether coronary dimensions adjusted for body surface area (Z scores) on baseline echocardiography and clinical variables before primary treatment could predict the presence of late CAAs.Methods: We conducted a retrospective study including children hospitalized for Kawasaki disease and received intravenous immunoglobulin within 10 days of illness. We defined late CAAs as a maximum Z score (Zmax) ≥2.5 of the left main, right, or left anterior descending coronary artery at 11–60 days of illness. Associations between late CAAs and clinical parameters and baseline maximum Z scores were analyzed.Results: Among the 314 included children, 31 (9.9%) had late CAAs. Male, higher C-reactive protein, and higher baseline Zmax were risk factors of late CAAs. Late CAAs were significantly associated with baseline Zmax ≥2.0 vs. &lt;2.0 (25 [32.5%] vs. 6 [2.5%], P &lt; 0.001). The odds ratio for late CAAs among the patients with baseline Zmax ≥2.0 vs. &lt;2.0 was 18.5 (95% confidence interval, 7.23 to 47.41, P &lt; 0.001). The sensitivity, specificity, positive predictive value, and negative predictive value of baseline Zmax ≥2.0 for the presence of later CAAs were 80.6, 81.6, 32.5, and 97.5%, respectively.Conclusions: Findings from this study suggest that Zmax ≥2.0 of coronary arteries on baseline echocardiography may be used to predict children at a high risk of late CAAs and allow for targeted early intensification therapy.

Coronary artery aneurysms in children is not always Kawasaki disease: a case report on Takayasu arteritis

Background Coronary artery (CA) aneurysms in children are a rare but potentially life-threatening finding and are highly associated with Kawasaki disease (KD). Case presentation We describe a four-year-old female with a vasculitis and CA aneurysms. She had a prolonged course with recurrent fever and systemic inflammation several times upon discontinuation of steroid treatment. Due in part to the CA aneurysms, she initially was diagnosed with KD but due to the unusual clinical course, further evaluation was performed. Abdominal and chest MRI/A revealed diffuse aortitis suggestive of a large vessel vasculitis, specifically Takayasu arteritis. With treatment targeted for Takayasu arteritis, there was resolution of fever and inflammation and the CA aneurysms improved. Conclusions This case demonstrates the utility in broadening the differential diagnosis in cases of presumed KD with CA involvement in which the clinical course is atypical for KD.