Table 2. Demographic and clinical information for MIS-C patients biallelic for deleterious variants of the OAS–RNase L pathway.

IEI, inborn error of immunity; SCV2, SARS-CoV-2; IVIG, intravenous immunoglobulins; ND, not determined; CRP, C-reactive protein; sCD25, soluble IL-2Rα.

Patient	P1	P2	P3	P4	P5
IEI (inheritance mode)	OAS1 (AR)	OAS2 (AR)	OAS2 (AR)	OAS2 (AR)	RNASEL (AR)
Age at MIS-C diagnosis	3 months	3 years	14 years	9 years	4 years
Sex	Male	Male	Female	Female	Female
Ethnicity	Filipino	Spanish	Turkish	Turkish	French Canadian
Resident country	Spain	Spain	Turkey	Turkey	Canada
SCV2 virology	Nasal swab PCR (−); blood PCR (−); blood anti-SCV2 IgG (+); blood antigen N (−)	Nasal swab PCR (−); blood PCR (−); blood anti-SCV2 IgG (+); blood antigen N (−)	Nasal swab PCR (−); blood PCR (ND); blood total anti-SCV2 (+); blood antigen N (ND)	Nasal swab PCR (−); blood PCR (ND); blood anti-SCV2 IgM and IgG (+); blood antigen N (ND)	Nasal swab PCR (−); blood PCR (−); blood anti-SCV2 IgG (+); blood antigen N (−)
Hemogram	Normal	Normal	Normal	Normal	Normal
Increased markers of multiorgan inflammation	CRP, ferritin, pro-BNP, GM-CSF, IL-1RA, MCP1, sCD25, IL-18, TNF	CRP, ferritin, pro-BNP, MCP1, sCD25, IL-1RA, IL-18, TNF	CRP, ferritin, troponin	Ferritin, troponin, pro-BNP	sCD25
TRBV 11-2 expansion	(−)	(−)	ND	ND	(+)
Clinical presentation	Kawasaki-like disease: fever, gastrointestinal symptoms, hepatosplenomegaly, aseptic meningitis with neurological symptoms (irritability), peripheral edema, lymphadenopathy, bilateral coronary aneurysm (Z score +8, +8.7), possible cerebral arterial aneurysm	Kawasaki disease: fever, rash, bilateral eyelid edema and erythema, conjunctival hyperemia	Kawasaki-like disease: fever, rash, bilateral nonpurulent conjunctivitis, strawberry tongue, abdominal pain, vomiting,dyspnea, mild mitral insufficiency. One and a half months prior,the patient had fever, headache, and sore throat when her mother had COVID-19. The patient developed oligoarticular juvenile idiopathic arthritis 5 months after MIS-C.	Fever, vomiting, coughing, myocarditis, left ventricular failure, pulmonary edema with paracardiac infiltration, polyneuropathy	Kawasaki disease: fever, rash, erythema and edema of the feet,anterior uveitis, cervical lymphadenopathy
Treatment	IVIG, aspirin, corticosteroids, anticoagulation therapy	IVIG, aspirin	IVIG, methylprednisolone, heparin	IVIG, pulse steroid, anakinra, mechanical ventilation	IVIG
Outcome	Recovery	Recovery	Recovery, but with persistent arthralgia in both knees 1.5 years after MIS-C	Recovery	Recovery