%0 Journal Article %J J Rheumatol %D 2016 %T Clinical Characteristics of Patients Carrying the Q703K Variant of the NLRP3 Gene: A 10-year Multicentric National Study. %A Naselli, Aldo %A Penco, Federica %A Cantarini, Luca %A Insalaco, Antonella %A Alessio, Mariolina %A Tommasini, Alberto %A Maggio, Cristina %A Obici, Laura %A Gallizi, Romina %A Cimmino, Marco %A Signa, Sara %A Lucherini, Orso Maria %A Carta, Sonia %A Caroli, Francesco %A Martini, Alberto %A Rubartelli, Anna %A Ceccherini, Isabella %A Gattorno, Marco %X

OBJECTIVE: The aim of our study was to analyze the clinical and functional effect of the p.Q703K (p. Q705K, c. 2107C>A) variant of the NLRP3 gene in a population of patients screened for suspected cryopyrin-associated periodic syndrome (CAPS).

METHODS: Since 2002, 580 patients underwent molecular analysis for NLRP3. Data on clinical presentation, response to treatment, and longterm followup were collected using a uniform questionnaire. The pattern of cytokine secretion after lipopolysaccharide stimulation from isolated monocytes was analyzed in 3 patients carrying the p.Q703K variant and 1 patient with a chronic infantile neurologic, cutaneous, articular syndrome phenotype carrying both the p.M406I and p.Q703K, and compared with 7 patients with CAPS with sure pathogenic variants and 6 healthy controls.

RESULTS: The p.Q703K variant was found in 57 screened patients with an overall allelic frequency of 5%. The frequency in normal controls was 5.5%. Clinical data at the moment of molecular analysis and at followup were available in 36 patients. Two patients displayed additional mutations of NLRP3. The mean followup was 2.5 years. Thirteen patients (39%) had a final diagnosis different from the original suspicion of CAPS. The remaining 21 patients displayed a mild phenotype mainly characterized by recurrent episodes of urticarial rash and arthralgia. Only 8 patients were treated with anti-interleukin (IL)-1 treatment, with a complete response in 5 patients. The pattern of secretion of IL-1β and other cytokines (IL-6 and IL-1 receptor antagonist) in patients did not display the aberrancies observed in patients with CAPS and was similar to that observed in healthy controls.

CONCLUSION: The present study confirms the weak clinical and functional effect of the p.Q703K variant.

%B J Rheumatol %V 43 %P 1093-100 %8 2016 Jun %G eng %N 6 %1 http://www.ncbi.nlm.nih.gov/pubmed/27036377?dopt=Abstract %R 10.3899/jrheum.150962 %0 Journal Article %J Ann Rheum Dis %D 2015 %T Next-generation sequencing and its initial applications for molecular diagnosis of systemic auto-inflammatory diseases. %A Rusmini, Marta %A Federici, Silvia %A Caroli, Francesco %A Grossi, Alice %A Baldi, Maurizia %A Obici, Laura %A Insalaco, Antonella %A Tommasini, Alberto %A Caorsi, Roberta %A Gallo, Eleonora %A Olivieri, Alma Nunzia %A Marzano, AngeloValerio %A Coviello, Domenico %A Ravazzolo, Roberto %A Martini, Alberto %A Gattorno, Marco %A Ceccherini, Isabella %X

OBJECTIVES: Systemic auto-inflammatory disorders (SAIDs) are a heterogeneous group of monogenic diseases sharing a primary dysfunction of the innate immune system. More than 50% of patients with SAID does not show any mutation at gene(s) tested because of lack of precise clinical classification criteria and/or incomplete gene screening. To improve the molecular diagnosis and genotype interpretation of SAIDs, we undertook the development of a next-generation sequencing (NGS)-based protocol designed to simultaneous screening of 10 genes.

METHODS: Fifty patients with SAID, already genotyped for the respective causative gene(s), were massively sequenced for the coding portions of MEFV, MVK, TNFRSF1A, NLRP3, NLRP12, NOD2, PSTPIP1, IL1RN, LPIN2 and PSMB8. Three different bioinformatic pipelines (Ion Reporter, CLC Bio Genomics Workbench, GATK-based in-house workflow) were compared.

RESULTS: Once resulting variants were compared with the expected mutation list, no workflow turned out to be able to detect all the 79 variants known in the 50 DNAs. Additional variants were also detected, validated by Sanger sequencing and compared to assess true and false positive detection rates of the three workflows. Finally, the overall clinical picture of 34 patients was re-evaluated in the light of the new mutations found.

CONCLUSIONS: The present gene panel has resulted suitable for molecular diagnosis of SAIDs. Moreover, genotype-phenotype correlation has confirmed that the interpretation of NGS data in patients with an undefined inflammatory phenotype is remarkably difficult, thus supporting the need of evidence-based and validated clinical criteria to be used concurrently with the genetic analysis for the final diagnosis and classification of patients with SAIDs.

%B Ann Rheum Dis %8 2015 Sep 17 %G ENG %1 http://www.ncbi.nlm.nih.gov/pubmed/26386126?dopt=Abstract %R 10.1136/annrheumdis-2015-207701