A Three-Generation Muckle-Wells Syndrome Family: Detailed Family History, Physical Examination, and Inter-Departmental Collaboration

Cryopyrin-associated periodic syndrome (CAPS) is a rare inherited autoinflammatory disease caused by gain-of-function mutations in the NLRP3 gene, with a genotype-phenotype correlation. The clinical presentation of each mutation has been previously studied. However, very few studies have reported on the clinical characteristics and treatment effectiveness across different generations within a family with the same mutation. A detailed investigation of family members of patients with CAPS may help in the appropriate diagnosis and treatment of undiagnosed CAPS. Herein, we report a 2-year-old boy (proband), his father, and his grandmother who presented with several symptoms of CAPS, such as persistently positive inflammatory reactions and hearing impairment. All three patients had the same pathogenic mutation in the NLRP3 gene (c.1049C>T (p.Thr350Met) heterozygous mutation) and were diagnosed with CAPS. With canakinumab treatment, the laboratory data of all three patients improved, the proband and father's skin rash disappeared, and his grandmother's arthropathy improved. The proband's hearing also showed slight improvement, but not in his father or grandmother. Among the various non-specific symptoms associated with CAPS, chronic ocular hyperemia is a finding that can be easily identified by non-ophthalmologists. Diagnosis of CAPS should be considered when eye symptoms are present in a combination of hyperinflammatory response, arthropathy, or skin symptoms. Thorough family history records, physical examinations, and close collaboration between pediatricians and adult rheumatologists are important for prompt diagnosis and appropriate treatment of inherited autoinflammatory diseases.