The aim of this study was to describe the clinical and molecular genetic findings in seven individuals from three unrelated families with Blau syndrome. A complex ophthalmic and general health examination including diagnostic imaging was performed. The NOD2 mutational hot spot located in exon 4 was Sanger sequenced in all three probands. Two individuals also underwent autoinflammatory disorder gene panel screening, and in one subject, exome sequencing was performed. Blau syndrome presenting as uveitis, skin rush or arthritis was diagnosed in four cases from three families. In two individuals from one family, only camptodactyly was noted, while another member had camptodactyly in combination with non-active uveitis and angioid streaks. One proband developed two attacks of meningoencephalitis attributed to presumed neurosarcoidosis, which is a rare finding in Blau syndrome. The probands from families 1 and 2 carried pathogenic variants in NOD2 (NM_022162.3): c.1001G>A p.(Arg334Gln) and c.1000C>T p.(Arg334Trp), respectively. In family 3, two variants of unknown significance in a heterozygous state were found: c.1412G>T p.(Arg471Leu) in NOD2 and c.928C>T p.(Arg310*) in NLRC4 (NM_001199139.1). In conclusion, Blau syndrome is a phenotypically highly variable, and there is a need to raise awareness about all clinical manifestations, including neurosarcoidosis. Variants of unknown significance pose a significant challenge regarding their contribution to etiopathogenesis of autoinflammatory diseases.

• Klíčová slova
• Blau syndrome, NOD2, autoinflammation, early onset sarcoidosis, neurosarcoidosis, uveitis,
• MeSH
• artritida * genetika   diagnóza   MeSH
• dědičné zánětlivé autoimunitní nemoci MeSH
• lidé MeSH
• lymfedém genetika   diagnóza   MeSH
• mutace * MeSH
• nemoci centrálního nervového systému MeSH
• neuropatická artropatie genetika   diagnóza   MeSH
• rodokmen * MeSH
• sarkoidóza * genetika   diagnóza   MeSH
• sekvenování exomu MeSH
• signální adaptorový protein Nod2 * genetika   MeSH
• synovitida * genetika   diagnóza   MeSH
• uveitida * genetika   diagnóza   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Názvy látek
• NOD2 protein, human MeSH Prohlížeč
• signální adaptorový protein Nod2 * MeSH

Blau syndrome (BS) is an auto-inflammatory granulomatous disease that possibly involves abnormal response to interferon gamma (IFNγ) due to exaggerated nucleotide-binding oligomerization domain containing 2 (NOD2) activity. Mendelian susceptibility to mycobacterial diseases (MSMD) is an infectious granulomatous disease that is caused by impaired production of or response to IFNγ. We report a mother and daughter who are both heterozygous for NOD2c.2264C˃T variant and dominant-negative IFNGR1818del4 mutation. The 17-year-old patient displayed an altered form of BS and milder form of MSMD, whereas the 44-year-old mother was completely asymptomatic. This experiment of nature supports the notion that IFNγ is an important driver of at least some BS manifestations and that elucidation of its involvement in the disease immunopathogenesis may identify novel therapeutic targets.

• Klíčová slova
• Blau syndrome, IFNγ, IFNγR1, MSMD, NOD2, WES, methotrexate,
• MeSH
• artritida genetika   MeSH
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mutace genetika   MeSH
• receptor interferonu gama MeSH
• receptory interferonů nedostatek   genetika   MeSH
• sarkoidóza genetika   MeSH
• signální adaptorový protein Nod2 genetika   MeSH
• synovitida genetika   MeSH
• uveitida genetika   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH
• Názvy látek
• NOD2 protein, human MeSH Prohlížeč
• receptory interferonů MeSH
• signální adaptorový protein Nod2 MeSH