Cryopyrin-Associated Periodic Syndrome (CAPS) Caused by c.943A>G Variant of NLRP3 Gene: Clinical Case

Abstract

Background. Cryopyrin-associated periodic syndromes is a group of rare congenital autoinflammatory diseases such as familial cold autoinflammatory syndrome, Muckle-Wells syndrome and chronic infantile neurological cutaneous articular syndrome. These syndromes are considered as clinical variants of one disease with different intensity of clinical features and severity of pathologic process. The onset of these syndromes is usually on the first year of life, and they start with fever, urticarial rash, various variants of joint diseases (from arthralgia to residual and persistent arthritis) and nervous system disturbances. There are only single case reports of cryopyrin-associated periodic syndromes in Russia.Clinical Case Description. The disease onset was at the age of 1 year 8 months with fever and rash as well as generalized joint syndrome. Autoinflammatory syndrome was suspected due to to results of blood tests, MRI, molecular genetic testing. Exons 2, 3 and 4 of TNFRSF1A gene and exon 4 of NLRP3 gene with nearby introns were studied with the method of direct automated sequencing. The c.943A>G variant in heterozygous state in NLRP3 gene was revealed. The child was treated with IL-1 beta inhibitor (canakinumab) with positive effect.Conclusion. Diagnostics of cryopyrin-associated periodic syndrome in children is the serious challenge. Timely decision with help of molecular genetic methods is crucial for successful target therapy.

Keywords

• children
• autoinflammatory syndromes
• cryopyrin-associated periodic syndrome
• tnfrsf1a gene
• nlrp3 gene
• il-1 beta inhibitor canakinumab