Exploratory Study of MYD88 L265P, Rare NLRP3 Variants, and Clonal Hematopoiesis Prevalence in Patients With Schnitzler Syndrome

Abstract

Objective Assess the prevalence of the MYD88 L265P mutation and variants within NLRP3, also to evaluate the status of oligoclonal haematopoiesis in 30 patients with Schnitzler Syndrome (SchS). Methods 30 patients with SchS were recruited from 3 clinical centres. 6 patients with known acquired cryopyrin associated periodic syndrome (aCAPS) were included as controls. Allele‐Specific Oligonucleotide PCR (ASO‐PCR) for detection of the MYD88 L265P variant, Next‐Generation Sequencing (NGS) of NLRP3 and 28 genes associated with Myelodysplastic Syndrome (MDS) and Gene Scanning for X inactivation. Results Activating NLRP3 mutations were not present within 11 SchS patients, who have not been sequenced for this gene previously. The MYD88 L265P variant was present in 9/30 SchS patients and somatic mutations associated with Clonal Hematopoiesis (CH) were identified in 1/30 SchS and 1/6 aCAPS patients. Evidence of non‐random X inactivation was detected in one female with SchS and one female aCAPS patient. Conclusion A shared molecular mechanism accounting for the pathogenesis of inflammation in SchS remains elusive. CH is not associated with other somatic mutations found in SchS or aCAPS patients.