◆

Subtypes

2

Familial Blau Syndrome

Autosomal dominant form caused by inherited NOD2 gain-of-function mutations. Classic triad of granulomatous arthritis, dermatitis, and uveitis with onset before age 4.

Show evidence (1 reference)

PMID:41678017 SUPPORT Human Clinical

"Blau syndrome is an autosomal dominant disease primarily occurring in children and is caused by highly penetrant NOD2 variants"

Confirms autosomal dominant inheritance with highly penetrant NOD2 variants in children.

Early-Onset Sarcoidosis (Sporadic)

Sporadic form with de novo NOD2 mutations, clinically indistinguishable from familial Blau syndrome. Previously termed early-onset sarcoidosis (EOS).

Show evidence (2 references)

PMID:17968944 SUPPORT Human Clinical

"Of the 12 cases, 58.3% were sporadic, due to de novo mutations"

Spanish cohort confirms majority of cases are sporadic with de novo NOD2 mutations.

PMID:17009307 SUPPORT Human Clinical

"Blau syndrome and its sporadic counterpart, early-onset sarcoidosis, share an identical phenotype featuring the classic triad of arthritis, dermatitis, and uveitis and are associated with mutations of CARD15 in 50-90% of cases"

International registry confirms identical phenotype between familial and sporadic forms.

⚙

Pathophysiology

6

NOD2 Gain-of-Function Activation

Blau syndrome is caused by gain-of-function mutations in NOD2 (CARD15), predominantly in the nucleotide-binding oligomerization domain (NOD/NACHT). These mutations lead to constitutive activation of NF-kB signaling, resulting in excessive pro-inflammatory cytokine production and non-caseating granuloma formation in affected tissues.

Macrophage link

NOD2 Signaling Pathway link ↑ INCREASED NF-kB Signaling link ↑ INCREASED

Downstream

Granulomatous Inflammation Constitutive NOD2 activation drives granuloma formation in joints, skin, and eyes.

Show evidence (4 references)

PMID:11528384 SUPPORT Human Clinical

"We have identified three missense mutations in the nucleotide-binding domain (NBD) of CARD15/NOD2 in four French and German families with Blau syndrome"

Landmark paper identifying CARD15/NOD2 NBD mutations as the cause of Blau syndrome.

PMID:29697845 SUPPORT In Vitro

"HEK293 cells transfected with the mutated cDNA showed a 20-fold increase of NF-kB activation in basal condition"

Functional studies of a related NOD2 gain-of-function mutation (R426H) demonstrate constitutive NF-kB activation, supporting the general mechanism in Blau syndrome.

PMID:38740600 SUPPORT Human Clinical

"Gene mutations of NOD2 lead to the development of autoimmune diseases such as Crohn's disease and Blau syndrome"

Review confirms NOD2 mutations drive Blau syndrome pathogenesis.

+ 1 more reference

Granulomatous Inflammation

Constitutive NOD2 activation drives formation of non-caseating epithelioid granulomas in joints, skin, and uveal tract. Multinucleated giant cells and epithelioid macrophages accumulate, causing tissue damage and organ dysfunction.

Epithelioid macrophage link Multinucleated giant cell link

Inflammatory Response link ↑ INCREASED

Downstream

Joint Destruction Granulomatous synovitis causes progressive polyarthritis.

Ocular Inflammation Granulomatous uveitis threatens vision.

Cutaneous Granulomatosis Non-caseating granulomas form in the dermis.

Visceral and Vascular Involvement Granulomatous inflammation extends to visceral organs and the vasculature.

Show evidence (1 reference)

PMID:17968944 SUPPORT Human Clinical

"Blau syndrome and early-onset sarcoidosis are NOD2 gene-associated chronic autoinflammatory diseases characterized by skin rash, arthritis, and/or eye involvement, with noncaseating granulomata as their pathologic hallmark"

Confirms non-caseating granulomas as the defining pathological feature.

Joint Destruction

Granulomatous synovitis leads to progressive polyarthritis with boggy synovial swelling, loss of range of motion, and potential joint destruction. Wrists, ankles, knees, and small joints of hands are most commonly affected.

Synovial cell link

Show evidence (1 reference)

PMID:25416713 SUPPORT Human Clinical

"The most frequently involved joints at presentation were wrists, ankles, knees and PIPs"

Confirms characteristic joint distribution pattern in Blau syndrome.

Ocular Inflammation

Granulomatous uveitis, typically panuveitis, is the most sight-threatening manifestation. Can progress to cataracts, glaucoma, band keratopathy, and blindness if untreated.

Inflammatory Response link ↑ INCREASED

Show evidence (2 references)

PMID:25416713 SUPPORT Human Clinical

"Ocular disease was documented in 25 of 31 patients, with vitreous inflammation in 64% and moderate-severe visual loss in 33%"

Confirms high prevalence of ocular disease with significant visual morbidity.

PMID:17009307 SUPPORT Human Clinical

"Eye disease was bilateral in 21 of 22 patients and was complicated by glaucoma in 6 of 22 patients and by cataracts in 50% of patients"

Documents severe visual complications including cataracts and glaucoma.

Cutaneous Granulomatosis

Skin involvement manifests as a symmetrical, tan-colored, papular or lichenoid rash, often the earliest clinical sign. Biopsy reveals non-caseating granulomas in the dermis.

Show evidence (1 reference)

PMID:17009307 SUPPORT Human Clinical

"Cutaneous presentation was the most common"

International registry confirms skin rash as the most common presenting feature.

Visceral and Vascular Involvement

Beyond the classic triad, Blau syndrome can involve visceral organs (liver, kidney, lung) and vasculature. Interstitial lung disease and vasculitis represent expanded manifestations that may be life-threatening.

Show evidence (2 references)

PMID:25416713 SUPPORT Human Clinical

"Expanded manifestations (visceral, vascular) beyond the classic clinical triad were seen in 52%"

Multicentre study reveals visceral and vascular involvement in over half of patients.

PMID:40350497 SUPPORT Human Clinical

"Incidence of vasculitis and interstitial lung disease were 27.7% and 17.0%, respectively"

Chinese cohort quantifies frequency of vasculitis and lung involvement.

⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.

●

Phenotypes

10

Cardiovascular 1

Vasculitis OCCASIONAL Vasculitis (HP:0002633)

Show evidence (1 reference)

PMID:40350497 SUPPORT Human Clinical

"Incidence of vasculitis and interstitial lung disease were 27.7% and 17.0%, respectively"

Chinese cohort shows vasculitis in 27.7% of patients.

Eye 3

Granulomatous Uveitis FREQUENT Panuveitis (HP:0012121)

Show evidence (2 references)

PMID:25416713 SUPPORT Human Clinical

"Ocular disease was documented in 25 of 31 patients, with vitreous inflammation in 64% and moderate-severe visual loss in 33%"

Ocular disease present in 81% of the multicentre cohort.

PMID:17009307 SUPPORT Human Clinical

"Isolated eye disease was never the presenting symptom, but significant/severe visual impairment was observed in 41% of patients"

International registry confirms significant visual morbidity from uveitis.

Visual Impairment FREQUENT Visual impairment (HP:0000505)

Show evidence (1 reference)

PMID:17009307 SUPPORT Human Clinical

"significant/severe visual impairment was observed in 41% of patients"

International registry documents visual impairment in 41% of patients.

Cataract FREQUENT Cataract (HP:0000518)

Show evidence (1 reference)

PMID:17009307 SUPPORT Human Clinical

"cataracts in 50% of patients"

International registry documents cataracts in half of patients with ocular disease.

Immune 1

Granulomatous Dermatitis FREQUENT Skin rash (HP:0000988)

Show evidence (2 references)

PMID:17009307 SUPPORT Human Clinical

"Cutaneous presentation was the most common"

International registry confirms skin rash as the most common presenting feature.

PMID:40350497 SUPPORT Human Clinical

"At baseline, incidence of fever, arthritis, rash, dermatitis and uveitis were 34%, 93.6%, 72.3% and 31.9%"

Rash/dermatitis present in 72.3% of Chinese cohort.

Metabolism 1

Fever FREQUENT Recurrent fever (HP:0001954)

Show evidence (2 references)

PMID:40350497 SUPPORT Human Clinical

"At baseline, incidence of fever, arthritis, rash, dermatitis and uveitis were 34%, 93.6%, 72.3% and 31.9%"

Fever present in 34% of Chinese cohort at baseline.

PMID:17968944 SUPPORT Human Clinical

"Novel atypical manifestations such as persistent fever and myocardiopathy were also observed"

Spanish cohort identifies persistent fever as an atypical manifestation.

Musculoskeletal 2

Camptodactyly Camptodactyly (HP:0012385)

Show evidence (1 reference)

PMID:38927735 SUPPORT Human Clinical

"In two individuals from one family, only camptodactyly was noted, while another member had camptodactyly in combination with non-active uveitis and angioid streaks"

Brichova 2024 case series documents camptodactyly as a presenting feature in multiple family members with Blau syndrome.

Bone Dysplastic Changes FREQUENT Skeletal dysplasia (HP:0002652)

Show evidence (1 reference)

PMID:25416713 SUPPORT Human Clinical

"Previously unknown dysplastic bony changes were found in two-thirds of patients"

Multicentre study discovers bone dysplastic changes in 66% of patients, a novel finding with potential diagnostic value.

Respiratory 1

Interstitial Lung Disease OCCASIONAL Abnormal pulmonary interstitial morphology (HP:0006530)

Show evidence (1 reference)

PMID:40350497 SUPPORT Human Clinical

"Incidence of vasculitis and interstitial lung disease were 27.7% and 17.0%, respectively"

Chinese cohort shows interstitial lung disease in 17% of patients.

Other 1

Granulomatous Arthritis VERY_FREQUENT Polyarticular arthritis (HP:0005764)

Show evidence (3 references)

PMID:25416713 SUPPORT Human Clinical

"Arthritis, documented in all but one patient, was oligoarticular in 7, polyarticular in 23"

Multicentre study shows arthritis in 30/31 patients, polyarticular in the majority.

PMID:40350497 SUPPORT Human Clinical

"At baseline, incidence of fever, arthritis, rash, dermatitis and uveitis were 34%, 93.6%, 72.3% and 31.9%"

Chinese cohort confirms arthritis in 93.6% of patients.

PMID:17009307 SUPPORT Human Clinical

"Arthritis was polyarticular in 96% of patients"

International registry confirms polyarticular pattern in the vast majority.

🧬

Genetic Associations

1

NOD2 (Pathogenic Variants)

Autosomal dominant

Show evidence (5 references)

PMID:11528384 SUPPORT Human Clinical

"We have identified three missense mutations in the nucleotide-binding domain (NBD) of CARD15/NOD2 in four French and German families with Blau syndrome"

Landmark paper identifying CARD15/NOD2 as the causative gene with mutations in the NBD.

PMID:25416713 SUPPORT Human Clinical

"Of the 31 patients, 11 carried the p.R334W NOD2 mutation, 9 the p.R334Q and 11 various other NOD2 missense mutations; 20 patients were sporadic and 11 from five BS pedigrees"

Multicentre study shows R334W and R334Q are the most common mutations.

PMID:17968944 SUPPORT Human Clinical

"NOD2 analysis revealed 1 heterozygous mutation in each patient, and familial studies confirmed its full penetrance"

Confirms heterozygous mutations with full penetrance.

+ 2 more references

💊

Treatments

5

Systemic Corticosteroids

Action: corticosteroid therapy Ontology label: Pharmacotherapy NCIT:C15986

Agent: corticosteroid ↗

First-line treatment for acute flares, particularly uveitis. Effective for short-term inflammation control but long-term use limited by side effects.

Show evidence (1 reference)

PMID:40350497 SUPPORT Human Clinical

"Approximately 95.7% patients (45 patients) were treated with combination of prednisolone and methotrexate"

Chinese cohort shows corticosteroids used in 95.7% of patients as backbone therapy.

Methotrexate

Action: methotrexate therapy Ontology label: Pharmacotherapy NCIT:C15986

Agent: methotrexate ↗

Disease-modifying agent used as steroid-sparing therapy for joint and skin manifestations. Often used as first-line maintenance therapy.

Show evidence (1 reference)

PMID:40350497 SUPPORT Human Clinical

"Approximately 95.7% patients (45 patients) were treated with combination of prednisolone and methotrexate"

Methotrexate combined with prednisolone is the standard first-line regimen.

Anti-TNF Biologic Therapy

Action: anti-TNF biologic therapy Ontology label: Pharmacotherapy NCIT:C15986

Agent: adalimumab ↗

TNF inhibitors (adalimumab, infliximab) used for refractory disease, particularly uveitis and arthritis unresponsive to conventional DMARDs.

Show evidence (2 references)

PMID:40350497 SUPPORT Human Clinical

"42.6% patients (20 patients) were treated with tumor necrosis factor inhibitors"

TNF inhibitors used in 42.6% of patients in Chinese cohort.

PMID:40350497 SUPPORT Human Clinical

"Patients treated with TNF-α inhibitors had a higher remission rate"

Demonstrates TNF inhibitors achieve higher remission rates.

IL-1 Receptor Antagonist Therapy

Action: IL-1 receptor antagonist therapy Ontology label: Pharmacotherapy NCIT:C15986

Agent: anakinra ↗

Anakinra has shown efficacy in some refractory cases, targeting the IL-1-mediated inflammatory pathway downstream of NOD2 activation.

Show evidence (2 references)

PMID:17968944 SUPPORT Human Clinical

"In the patient who received anakinra treatment, all clinical inflammatory symptoms improved and plasma cytokine levels normalized"

First evidence of anakinra efficacy in Blau syndrome.

PMID:17968944 SUPPORT Human Clinical

"the pathogenesis of pediatric granulomatous arthritis may involve interleukin-1-mediated events"

Supports IL-1 pathway involvement in Blau syndrome pathogenesis.

JAK Inhibitor Therapy

Action: JAK inhibitor therapy Ontology label: Pharmacotherapy NCIT:C15986

Agent: tofacitinib ↗

Tofacitinib, a pan-JAK inhibitor, suppresses IFN-γ-induced NOD2 expression and downstream pro-inflammatory cytokine production. Emerging treatment for refractory Blau syndrome, with clinical trials underway.

Show evidence (2 references)

PMID:37415984 SUPPORT In Vitro

"Tofacitinib suppressed the induction of NOD2 by IFNγ, thereby inhibiting the production of pro-inflammatory cytokines"

iPSC-derived myeloid cell studies demonstrate tofacitinib suppresses NOD2 expression and cytokine production.

PMID:37415984 SUPPORT In Vitro

"The JAK inhibitor tofacitinib is a potential therapeutic agent for Blau syndrome because it suppresses the autoinflammation seen in Blau syndrome by inhibiting the expression of NOD2"

Mechanistic rationale for JAK inhibition as upstream blockade in Blau syndrome.

🔬

Clinical Trials

1

NCT06660329 PHASE_IV RECRUITING

Prospective cohort study evaluating the efficacy and safety of tofacitinib in children with refractory Blau syndrome, measuring remission rate, inflammatory markers, and disease activity at 6 months.

Show evidence (1 reference)

clinicaltrials:NCT06660329 SUPPORT

"This is a prospective cohort study to observe the efficacy and safety of Tofacitinib in children with Blau syndrome (BS)"

First prospective trial of JAK inhibitor therapy specifically for refractory Blau syndrome.

{ }

Source YAML

click to show

name: Blau Syndrome
creation_date: "2026-04-23T05:00:56Z"
updated_date: "2026-04-23T05:00:56Z"
category: Mendelian
disease_term:
  preferred_term: Blau syndrome
  term:
    id: MONDO:0008523
    label: Blau syndrome
parents:
- Autoinflammatory Disease
- Granulomatous Disease
has_subtypes:
- name: Familial
  display_name: Familial Blau Syndrome
  description: >
    Autosomal dominant form caused by inherited NOD2 gain-of-function mutations.
    Classic triad of granulomatous arthritis, dermatitis, and uveitis with onset
    before age 4.
  evidence:
  - reference: PMID:41678017
    reference_title: "NOD2-Related Multisystem Inflammatory Disorders and Recent Advances."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Blau syndrome is an autosomal dominant disease primarily occurring in children and is caused by highly penetrant NOD2 variants"
    explanation: Confirms autosomal dominant inheritance with highly penetrant NOD2 variants in children.
- name: Sporadic
  display_name: Early-Onset Sarcoidosis (Sporadic)
  description: >
    Sporadic form with de novo NOD2 mutations, clinically indistinguishable from
    familial Blau syndrome. Previously termed early-onset sarcoidosis (EOS).
  evidence:
  - reference: PMID:17968944
    reference_title: "NOD2 gene-associated pediatric granulomatous arthritis: clinical diversity, novel and recurrent mutations, and evidence of clinical improvement with interleukin-1 blockade in a Spanish cohort."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Of the 12 cases, 58.3% were sporadic, due to de novo mutations"
    explanation: Spanish cohort confirms majority of cases are sporadic with de novo NOD2 mutations.
  - reference: PMID:17009307
    reference_title: "Pediatric granulomatous arthritis: an international registry."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Blau syndrome and its sporadic counterpart, early-onset sarcoidosis, share an identical phenotype featuring the classic triad of arthritis, dermatitis, and uveitis and are associated with mutations of CARD15 in 50-90% of cases"
    explanation: International registry confirms identical phenotype between familial and sporadic forms.
pathophysiology:
- name: NOD2 Gain-of-Function Activation
  description: >
    Blau syndrome is caused by gain-of-function mutations in NOD2 (CARD15),
    predominantly in the nucleotide-binding oligomerization domain (NOD/NACHT).
    These mutations lead to constitutive activation of NF-kB signaling,
    resulting in excessive pro-inflammatory cytokine production and
    non-caseating granuloma formation in affected tissues.
  cell_types:
  - preferred_term: Macrophage
    term:
      id: CL:0000235
      label: macrophage
  biological_processes:
  - preferred_term: NOD2 Signaling Pathway
    term:
      id: GO:0070431
      label: nucleotide-binding oligomerization domain containing 2 signaling pathway
    modifier: INCREASED
  - preferred_term: NF-kB Signaling
    term:
      id: GO:0007249
      label: canonical NF-kappaB signal transduction
    modifier: INCREASED
  evidence:
  - reference: PMID:11528384
    reference_title: "CARD15 mutations in Blau syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We have identified three missense mutations in the nucleotide-binding domain (NBD) of CARD15/NOD2 in four French and German families with Blau syndrome"
    explanation: Landmark paper identifying CARD15/NOD2 NBD mutations as the cause of Blau syndrome.
  - reference: PMID:29697845
    reference_title: "Novel NOD2 Mutation in Early-Onset Inflammatory Bowel Phenotype."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "HEK293 cells transfected with the mutated cDNA showed a 20-fold increase of NF-kB activation in basal condition"
    explanation: Functional studies of a related NOD2 gain-of-function mutation (R426H) demonstrate constitutive NF-kB activation, supporting the general mechanism in Blau syndrome.
  - reference: PMID:38740600
    reference_title: "Role and molecular mechanism of NOD2 in chronic non-communicable diseases."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Gene mutations of NOD2 lead to the development of autoimmune diseases such as Crohn's disease and Blau syndrome"
    explanation: Review confirms NOD2 mutations drive Blau syndrome pathogenesis.
  - reference: PMID:35711422
    reference_title: "Potential Benefits of TNF Targeting Therapy in Blau Syndrome, a NOD2-Associated Systemic Autoinflammatory Granulomatosis."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "abnormal cytokine expression in macrophages from untreated patients requires IFNγ stimulation, and that anti-TNF treatment corrects the abnormalities associated with Blau syndrome, even in the presence of IFNγ"
    explanation: iPSC-derived macrophage studies show IFN-γ priming is required for mutant NOD2 inflammatory output, and anti-TNF corrects the abnormalities.
  downstream:
  - target: Granulomatous Inflammation
    description: Constitutive NOD2 activation drives granuloma formation in joints, skin, and eyes.
- name: Granulomatous Inflammation
  description: >
    Constitutive NOD2 activation drives formation of non-caseating epithelioid
    granulomas in joints, skin, and uveal tract. Multinucleated giant cells and
    epithelioid macrophages accumulate, causing tissue damage and organ dysfunction.
  cell_types:
  - preferred_term: Epithelioid macrophage
    term:
      id: CL:0002150
      label: epithelioid macrophage
  - preferred_term: Multinucleated giant cell
    term:
      id: CL:0000647
      label: multinucleated giant cell
  biological_processes:
  - preferred_term: Inflammatory Response
    term:
      id: GO:0006954
      label: inflammatory response
    modifier: INCREASED
  evidence:
  - reference: PMID:17968944
    reference_title: "NOD2 gene-associated pediatric granulomatous arthritis: clinical diversity, novel and recurrent mutations, and evidence of clinical improvement with interleukin-1 blockade in a Spanish cohort."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Blau syndrome and early-onset sarcoidosis are NOD2 gene-associated chronic autoinflammatory diseases characterized by skin rash, arthritis, and/or eye involvement, with noncaseating granulomata as their pathologic hallmark"
    explanation: Confirms non-caseating granulomas as the defining pathological feature.
  downstream:
  - target: Joint Destruction
    description: Granulomatous synovitis causes progressive polyarthritis.
  - target: Ocular Inflammation
    description: Granulomatous uveitis threatens vision.
  - target: Cutaneous Granulomatosis
    description: Non-caseating granulomas form in the dermis.
  - target: Visceral and Vascular Involvement
    description: Granulomatous inflammation extends to visceral organs and the vasculature.
- name: Joint Destruction
  description: >
    Granulomatous synovitis leads to progressive polyarthritis with boggy
    synovial swelling, loss of range of motion, and potential joint destruction.
    Wrists, ankles, knees, and small joints of hands are most commonly affected.
  cell_types:
  - preferred_term: Synovial cell
    term:
      id: CL:0000214
      label: synovial cell
  evidence:
  - reference: PMID:25416713
    reference_title: "Blau syndrome: cross-sectional data from a multicentre study of clinical, radiological and functional outcomes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The most frequently involved joints at presentation were wrists, ankles, knees and PIPs"
    explanation: Confirms characteristic joint distribution pattern in Blau syndrome.
- name: Ocular Inflammation
  description: >
    Granulomatous uveitis, typically panuveitis, is the most sight-threatening
    manifestation. Can progress to cataracts, glaucoma, band keratopathy, and
    blindness if untreated.
  evidence:
  - reference: PMID:25416713
    reference_title: "Blau syndrome: cross-sectional data from a multicentre study of clinical, radiological and functional outcomes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Ocular disease was documented in 25 of 31 patients, with vitreous inflammation in 64% and moderate-severe visual loss in 33%"
    explanation: Confirms high prevalence of ocular disease with significant visual morbidity.
  - reference: PMID:17009307
    reference_title: "Pediatric granulomatous arthritis: an international registry."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Eye disease was bilateral in 21 of 22 patients and was complicated by glaucoma in 6 of 22 patients and by cataracts in 50% of patients"
    explanation: Documents severe visual complications including cataracts and glaucoma.
  biological_processes:
  - preferred_term: Inflammatory Response
    term:
      id: GO:0006954
      label: inflammatory response
    modifier: INCREASED
- name: Cutaneous Granulomatosis
  description: >
    Skin involvement manifests as a symmetrical, tan-colored, papular or
    lichenoid rash, often the earliest clinical sign. Biopsy reveals
    non-caseating granulomas in the dermis.
  evidence:
  - reference: PMID:17009307
    reference_title: "Pediatric granulomatous arthritis: an international registry."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Cutaneous presentation was the most common"
    explanation: International registry confirms skin rash as the most common presenting feature.
- name: Visceral and Vascular Involvement
  description: >
    Beyond the classic triad, Blau syndrome can involve visceral organs
    (liver, kidney, lung) and vasculature. Interstitial lung disease and
    vasculitis represent expanded manifestations that may be life-threatening.
  evidence:
  - reference: PMID:25416713
    reference_title: "Blau syndrome: cross-sectional data from a multicentre study of clinical, radiological and functional outcomes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Expanded manifestations (visceral, vascular) beyond the classic clinical triad were seen in 52%"
    explanation: Multicentre study reveals visceral and vascular involvement in over half of patients.
  - reference: PMID:40350497
    reference_title: "Long-term prognosis of 47 pediatric patients with Blau syndrome in China."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Incidence of vasculitis and interstitial lung disease were 27.7% and 17.0%, respectively"
    explanation: Chinese cohort quantifies frequency of vasculitis and lung involvement.
phenotypes:
- name: Granulomatous Arthritis
  category: Musculoskeletal
  description: >
    Polyarticular boggy synovitis with non-caseating granulomas, typically
    affecting wrists, ankles, knees, and interphalangeal joints. Usually the
    presenting feature, with onset before age 4.
  frequency: VERY_FREQUENT
  phenotype_term:
    preferred_term: Polyarticular arthritis
    term:
      id: HP:0005764
      label: Polyarticular arthritis
  evidence:
  - reference: PMID:25416713
    reference_title: "Blau syndrome: cross-sectional data from a multicentre study of clinical, radiological and functional outcomes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Arthritis, documented in all but one patient, was oligoarticular in 7, polyarticular in 23"
    explanation: Multicentre study shows arthritis in 30/31 patients, polyarticular in the majority.
  - reference: PMID:40350497
    reference_title: "Long-term prognosis of 47 pediatric patients with Blau syndrome in China."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "At baseline, incidence of fever, arthritis, rash, dermatitis and uveitis were 34%, 93.6%, 72.3% and 31.9%"
    explanation: Chinese cohort confirms arthritis in 93.6% of patients.
  - reference: PMID:17009307
    reference_title: "Pediatric granulomatous arthritis: an international registry."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Arthritis was polyarticular in 96% of patients"
    explanation: International registry confirms polyarticular pattern in the vast majority.
- name: Granulomatous Uveitis
  category: Ophthalmologic
  description: >
    Bilateral panuveitis with mutton-fat keratic precipitates, posterior
    synechiae, and risk of cataracts, glaucoma, and vision loss. Most
    sight-threatening complication.
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Panuveitis
    term:
      id: HP:0012121
      label: Panuveitis
  evidence:
  - reference: PMID:25416713
    reference_title: "Blau syndrome: cross-sectional data from a multicentre study of clinical, radiological and functional outcomes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Ocular disease was documented in 25 of 31 patients, with vitreous inflammation in 64% and moderate-severe visual loss in 33%"
    explanation: Ocular disease present in 81% of the multicentre cohort.
  - reference: PMID:17009307
    reference_title: "Pediatric granulomatous arthritis: an international registry."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Isolated eye disease was never the presenting symptom, but significant/severe visual impairment was observed in 41% of patients"
    explanation: International registry confirms significant visual morbidity from uveitis.
- name: Granulomatous Dermatitis
  category: Dermatologic
  description: >
    Symmetric, tan-colored or erythematous papular rash, often ichthyosiform
    or lichenoid in character. Usually the earliest clinical manifestation,
    appearing in infancy.
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Skin rash
    term:
      id: HP:0000988
      label: Skin rash
  evidence:
  - reference: PMID:17009307
    reference_title: "Pediatric granulomatous arthritis: an international registry."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Cutaneous presentation was the most common"
    explanation: International registry confirms skin rash as the most common presenting feature.
  - reference: PMID:40350497
    reference_title: "Long-term prognosis of 47 pediatric patients with Blau syndrome in China."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "At baseline, incidence of fever, arthritis, rash, dermatitis and uveitis were 34%, 93.6%, 72.3% and 31.9%"
    explanation: Rash/dermatitis present in 72.3% of Chinese cohort.
- name: Camptodactyly
  category: Musculoskeletal
  description: >
    Flexion contractures of fingers due to chronic granulomatous tenosynovitis,
    a characteristic feature of Blau syndrome joint involvement.
  phenotype_term:
    preferred_term: Camptodactyly
    term:
      id: HP:0012385
      label: Camptodactyly
  evidence:
  - reference: PMID:38927735
    reference_title: "Blau Syndrome: Challenging Molecular Genetic Diagnostics of Autoinflammatory Disease."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In two individuals from one family, only camptodactyly was noted, while another member had camptodactyly in combination with non-active uveitis and angioid streaks"
    explanation: Brichova 2024 case series documents camptodactyly as a presenting feature in multiple family members with Blau syndrome.
- name: Fever
  category: Constitutional
  description: >
    Intermittent fevers may occur, particularly during disease flares, reflecting
    the systemic autoinflammatory nature of the condition.
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Recurrent fever
    term:
      id: HP:0001954
      label: Recurrent fever
  evidence:
  - reference: PMID:40350497
    reference_title: "Long-term prognosis of 47 pediatric patients with Blau syndrome in China."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "At baseline, incidence of fever, arthritis, rash, dermatitis and uveitis were 34%, 93.6%, 72.3% and 31.9%"
    explanation: Fever present in 34% of Chinese cohort at baseline.
  - reference: PMID:17968944
    reference_title: "NOD2 gene-associated pediatric granulomatous arthritis: clinical diversity, novel and recurrent mutations, and evidence of clinical improvement with interleukin-1 blockade in a Spanish cohort."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Novel atypical manifestations such as persistent fever and myocardiopathy were also observed"
    explanation: Spanish cohort identifies persistent fever as an atypical manifestation.
- name: Visual Impairment
  category: Ophthalmologic
  description: >
    Progressive visual loss due to complications of chronic uveitis including
    cataracts, glaucoma, band keratopathy, and macular edema.
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Visual impairment
    term:
      id: HP:0000505
      label: Visual impairment
  evidence:
  - reference: PMID:17009307
    reference_title: "Pediatric granulomatous arthritis: an international registry."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "significant/severe visual impairment was observed in 41% of patients"
    explanation: International registry documents visual impairment in 41% of patients.
- name: Cataract
  category: Ophthalmologic
  description: >
    Secondary cataracts develop as a complication of chronic granulomatous
    uveitis and/or prolonged corticosteroid therapy.
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Cataract
    term:
      id: HP:0000518
      label: Cataract
  evidence:
  - reference: PMID:17009307
    reference_title: "Pediatric granulomatous arthritis: an international registry."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "cataracts in 50% of patients"
    explanation: International registry documents cataracts in half of patients with ocular disease.
- name: Vasculitis
  category: Cardiovascular
  description: >
    Systemic vasculitis affecting large and medium vessels, representing
    an expanded manifestation beyond the classic triad.
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Vasculitis
    term:
      id: HP:0002633
      label: Vasculitis
  evidence:
  - reference: PMID:40350497
    reference_title: "Long-term prognosis of 47 pediatric patients with Blau syndrome in China."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Incidence of vasculitis and interstitial lung disease were 27.7% and 17.0%, respectively"
    explanation: Chinese cohort shows vasculitis in 27.7% of patients.
- name: Interstitial Lung Disease
  category: Respiratory
  description: >
    Granulomatous interstitial lung disease may occur as part of the
    expanded visceral manifestations of Blau syndrome.
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Interstitial lung disease
    term:
      id: HP:0006530
      label: Abnormal pulmonary interstitial morphology
  evidence:
  - reference: PMID:40350497
    reference_title: "Long-term prognosis of 47 pediatric patients with Blau syndrome in China."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Incidence of vasculitis and interstitial lung disease were 27.7% and 17.0%, respectively"
    explanation: Chinese cohort shows interstitial lung disease in 17% of patients.
- name: Bone Dysplastic Changes
  category: Musculoskeletal
  description: >
    Dysplastic bony changes on radiographs, a previously unrecognized feature
    found in two-thirds of patients in the multicentre study. May suggest a
    role for NOD2 in bone morphogenesis and could have diagnostic value.
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Skeletal dysplasia
    term:
      id: HP:0002652
      label: Skeletal dysplasia
  evidence:
  - reference: PMID:25416713
    reference_title: "Blau syndrome: cross-sectional data from a multicentre study of clinical, radiological and functional outcomes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Previously unknown dysplastic bony changes were found in two-thirds of patients"
    explanation: Multicentre study discovers bone dysplastic changes in 66% of patients, a novel finding with potential diagnostic value.
genetic:
- name: NOD2
  association: Pathogenic Variants
  gene_term:
    preferred_term: NOD2
    term:
      id: hgnc:5331
      label: NOD2
  inheritance:
  - name: Autosomal dominant
    evidence:
    - reference: PMID:17968944
      reference_title: "NOD2 gene-associated pediatric granulomatous arthritis: clinical diversity, novel and recurrent mutations, and evidence of clinical improvement with interleukin-1 blockade in a Spanish cohort."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "NOD2 analysis revealed 1 heterozygous mutation in each patient, and familial studies confirmed its full penetrance"
      explanation: Heterozygous NOD2 mutations with full penetrance are consistent with autosomal dominant inheritance.
  features: >
    Blau syndrome is caused by heterozygous gain-of-function mutations in NOD2
    (CARD15) on chromosome 16q12. Mutations cluster in the central
    nucleotide-binding oligomerization domain (NOD/NACHT domain). The most
    common mutations include R334W, R334Q, and L469F. Sporadic cases
    (early-onset sarcoidosis) have de novo NOD2 mutations at the same loci.
  variants:
  - name: R334W
    description: >
      Most common Blau syndrome mutation. Arginine to tryptophan substitution
      in the NOD/NACHT domain leading to constitutive NF-kB activation.
    evidence:
    - reference: PMID:25416713
      reference_title: "Blau syndrome: cross-sectional data from a multicentre study of clinical, radiological and functional outcomes."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Of the 31 patients, 11 carried the p.R334W NOD2 mutation, 9 the p.R334Q and 11 various other NOD2 missense mutations"
      explanation: Multicentre cohort confirms p.R334W is the single most common Blau syndrome mutation.
  - name: R334Q
    description: >
      Arginine to glutamine substitution at the same position as R334W.
      Associated with classic Blau triad.
    evidence:
    - reference: PMID:25416713
      reference_title: "Blau syndrome: cross-sectional data from a multicentre study of clinical, radiological and functional outcomes."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Of the 31 patients, 11 carried the p.R334W NOD2 mutation, 9 the p.R334Q and 11 various other NOD2 missense mutations"
      explanation: Multicentre cohort documents p.R334Q in 9 of 31 Blau patients alongside R334W.
  - name: L469F
    description: >
      Leucine to phenylalanine substitution in the NOD/NACHT domain.
      Associated with typical Blau syndrome phenotype.
    evidence:
    - reference: PMID:11528384
      reference_title: "CARD15 mutations in Blau syndrome."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "We have identified three missense mutations in the nucleotide-binding domain (NBD) of CARD15/NOD2 in four French and German families with Blau syndrome"
      explanation: Original gene-discovery paper identifies missense mutations in the NBD/NOD/NACHT domain consistent with L469F.
  evidence:
  - reference: PMID:11528384
    reference_title: "CARD15 mutations in Blau syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We have identified three missense mutations in the nucleotide-binding domain (NBD) of CARD15/NOD2 in four French and German families with Blau syndrome"
    explanation: Landmark paper identifying CARD15/NOD2 as the causative gene with mutations in the NBD.
  - reference: PMID:25416713
    reference_title: "Blau syndrome: cross-sectional data from a multicentre study of clinical, radiological and functional outcomes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Of the 31 patients, 11 carried the p.R334W NOD2 mutation, 9 the p.R334Q and 11 various other NOD2 missense mutations; 20 patients were sporadic and 11 from five BS pedigrees"
    explanation: Multicentre study shows R334W and R334Q are the most common mutations.
  - reference: PMID:17968944
    reference_title: "NOD2 gene-associated pediatric granulomatous arthritis: clinical diversity, novel and recurrent mutations, and evidence of clinical improvement with interleukin-1 blockade in a Spanish cohort."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "NOD2 analysis revealed 1 heterozygous mutation in each patient, and familial studies confirmed its full penetrance"
    explanation: Confirms heterozygous mutations with full penetrance.
  - reference: PMID:37604356
    reference_title: "Distinct NOD2 mutations reported in three families with Blau syndrome (BS) from a single center in India - Case series and review of literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The first family had three affected members where the mother and her two children had skin changes, polyarthritis and a pathogenic mutation in NOD2 gene (exon 4, c.1000C > T, p.Arg334Trp) suggesting BS"
    explanation: Indian case series confirms R334W (Arg334Trp) in a familial Blau syndrome pedigree with classic triad.
  - reference: CGGV:assertion_1fd650d7-6a84-4b33-b86e-d34cab5b7d57-2020-10-07T171807.983Z
    reference_title: "NOD2 / Blau syndrome (Definitive)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "NOD2 | HGNC:5331 | Blau syndrome | MONDO:0008523 | AD | Definitive"
    explanation: ClinGen classifies the NOD2-Blau syndrome gene-disease relationship as definitive with autosomal dominant inheritance.
treatments:
- name: Systemic Corticosteroids
  description: >
    First-line treatment for acute flares, particularly uveitis. Effective
    for short-term inflammation control but long-term use limited by side effects.
  treatment_term:
    preferred_term: corticosteroid therapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: corticosteroid
      term:
        id: CHEBI:50858
        label: corticosteroid
  evidence:
  - reference: PMID:40350497
    reference_title: "Long-term prognosis of 47 pediatric patients with Blau syndrome in China."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Approximately 95.7% patients (45 patients) were treated with combination of prednisolone and methotrexate"
    explanation: Chinese cohort shows corticosteroids used in 95.7% of patients as backbone therapy.
- name: Methotrexate
  description: >
    Disease-modifying agent used as steroid-sparing therapy for joint and
    skin manifestations. Often used as first-line maintenance therapy.
  treatment_term:
    preferred_term: methotrexate therapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: methotrexate
      term:
        id: CHEBI:44185
        label: methotrexate
  evidence:
  - reference: PMID:40350497
    reference_title: "Long-term prognosis of 47 pediatric patients with Blau syndrome in China."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Approximately 95.7% patients (45 patients) were treated with combination of prednisolone and methotrexate"
    explanation: Methotrexate combined with prednisolone is the standard first-line regimen.
- name: Anti-TNF Biologic Therapy
  description: >
    TNF inhibitors (adalimumab, infliximab) used for refractory disease,
    particularly uveitis and arthritis unresponsive to conventional DMARDs.
  treatment_term:
    preferred_term: anti-TNF biologic therapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: adalimumab
      term:
        id: NCIT:C65216
        label: Adalimumab
  evidence:
  - reference: PMID:40350497
    reference_title: "Long-term prognosis of 47 pediatric patients with Blau syndrome in China."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "42.6% patients (20 patients) were treated with tumor necrosis factor inhibitors"
    explanation: TNF inhibitors used in 42.6% of patients in Chinese cohort.
  - reference: PMID:40350497
    reference_title: "Long-term prognosis of 47 pediatric patients with Blau syndrome in China."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Patients treated with TNF-α inhibitors had a higher remission rate"
    explanation: Demonstrates TNF inhibitors achieve higher remission rates.
- name: IL-1 Receptor Antagonist Therapy
  description: >
    Anakinra has shown efficacy in some refractory cases, targeting the
    IL-1-mediated inflammatory pathway downstream of NOD2 activation.
  treatment_term:
    preferred_term: IL-1 receptor antagonist therapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: anakinra
      term:
        id: CHEBI:231683
        label: Anakinra
  evidence:
  - reference: PMID:17968944
    reference_title: "NOD2 gene-associated pediatric granulomatous arthritis: clinical diversity, novel and recurrent mutations, and evidence of clinical improvement with interleukin-1 blockade in a Spanish cohort."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In the patient who received anakinra treatment, all clinical inflammatory symptoms improved and plasma cytokine levels normalized"
    explanation: First evidence of anakinra efficacy in Blau syndrome.
  - reference: PMID:17968944
    reference_title: "NOD2 gene-associated pediatric granulomatous arthritis: clinical diversity, novel and recurrent mutations, and evidence of clinical improvement with interleukin-1 blockade in a Spanish cohort."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the pathogenesis of pediatric granulomatous arthritis may involve interleukin-1-mediated events"
    explanation: Supports IL-1 pathway involvement in Blau syndrome pathogenesis.
- name: JAK Inhibitor Therapy
  description: >
    Tofacitinib, a pan-JAK inhibitor, suppresses IFN-γ-induced NOD2 expression
    and downstream pro-inflammatory cytokine production. Emerging treatment for
    refractory Blau syndrome, with clinical trials underway.
  treatment_term:
    preferred_term: JAK inhibitor therapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: tofacitinib
      term:
        id: CHEBI:71200
        label: tofacitinib
  evidence:
  - reference: PMID:37415984
    reference_title: "Tofacitinib, a suppressor of NOD2 expression, is a potential treatment for Blau syndrome."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Tofacitinib suppressed the induction of NOD2 by IFNγ, thereby inhibiting the production of pro-inflammatory cytokines"
    explanation: iPSC-derived myeloid cell studies demonstrate tofacitinib suppresses NOD2 expression and cytokine production.
  - reference: PMID:37415984
    reference_title: "Tofacitinib, a suppressor of NOD2 expression, is a potential treatment for Blau syndrome."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "The JAK inhibitor tofacitinib is a potential therapeutic agent for Blau syndrome because it suppresses the autoinflammation seen in Blau syndrome by inhibiting the expression of NOD2"
    explanation: Mechanistic rationale for JAK inhibition as upstream blockade in Blau syndrome.
clinical_trials:
- name: NCT06660329
  phase: PHASE_IV
  status: RECRUITING
  description: >
    Prospective cohort study evaluating the efficacy and safety of tofacitinib
    in children with refractory Blau syndrome, measuring remission rate,
    inflammatory markers, and disease activity at 6 months.
  evidence:
  - reference: clinicaltrials:NCT06660329
    supports: SUPPORT
    snippet: "This is a prospective cohort study to observe the efficacy and safety of Tofacitinib in children with Blau syndrome (BS)"
    explanation: First prospective trial of JAK inhibitor therapy specifically for refractory Blau syndrome.
datasets:

📚

References & Deep Research

Deep Research

1

Falcon ▸

Blau Syndrome (Mendelian) — Comprehensive Disease Characteristics Report

Edison Scientific Literature 32 citations 2026-04-22T22:38:13.319812

Blau Syndrome (Mendelian) — Comprehensive Disease Characteristics Report

Target disease: Blau syndrome (familial juvenile systemic granulomatosis; sporadic counterpart often termed early-onset sarcoidosis). (brichova2024blausyndromechallenging pages 1-2, shi2025longtermprognosisof pages 1-2)

Evidence base note: The synthesis below is derived from aggregated disease-level publications (case series/cohorts, mechanistic studies, and ClinicalTrials.gov records), not from EHR-only sources. (brichova2024blausyndromechallenging pages 1-2, shi2025longtermprognosisof pages 1-2, NCT06660329 chunk 1)

1. Disease Information

1.1 Overview (current understanding)

Blau syndrome is a rare, typically pediatric-onset, systemic autoinflammatory granulomatous disorder classically defined by the triad of granulomatous dermatitis, symmetric arthritis/tenosynovitis, and recurrent uveitis. (brichova2024blausyndromechallenging pages 1-2, shi2025longtermprognosisof pages 1-2)

1.2 Key identifiers (best available from retrieved sources)

OMIM disease: Blau syndrome #186580. (brichova2024blausyndromechallenging pages 1-2)
Gene: NOD2 (also referenced historically as CARD15). (shi2025longtermprognosisof pages 1-2, zhang2026clinicalfeaturestreatment pages 9-10)
MONDO ID / Orphanet / ICD / MeSH: Not available in the retrieved evidence set; should be added from external disease ontologies during downstream curation.

1.3 Synonyms / alternative names

Blau syndrome (BS). (brichova2024blausyndromechallenging pages 1-2)
Juvenile systemic granulomatosis (commonly used in reviews/clinical discussion; not explicitly enumerated in the extracted text set).
Early-onset sarcoidosis (EOS) is commonly used for sporadic/de novo presentations and is described as the “sporadic counterpart” in clinical genetics contexts. (shi2025longtermprognosisof pages 1-2, brichova2024blausyndromechallenging pages 11-13)

2. Etiology

2.1 Disease causal factors

Primary cause: heterozygous variants in NOD2, producing a dominantly inherited autoinflammatory granulomatous disorder. (brichova2024blausyndromechallenging pages 1-2, shi2025longtermprognosisof pages 1-2)

Key concept (mechanistic genotype class): Blau-associated NOD2 variants behave as gain-of-function with constitutive pro-inflammatory signaling (see §6). (matsuda2022potentialbenefitsof pages 1-2, ueki2023tofacitinibasuppressor pages 1-2)

2.2 Risk factors

Genetic risk factor (causal): pathogenic NOD2 variants—especially in the exon 4 hotspot (see §4). (brichova2024blausyndromechallenging pages 2-4)
Environmental risk factors: No consistent environmental exposures are established as causal in the retrieved sources; however, immune priming signals (e.g., IFN-γ–driven pathways) are mechanistically implicated as triggers/accelerants (see §6). (ueki2023tofacitinibasuppressor pages 1-2)

2.3 Protective factors

No protective genetic or environmental factors were identified in the retrieved sources.

2.4 Gene–environment interactions

Direct gene–environment interaction evidence is limited. Mechanistic work supports a model in which inflammatory cytokine milieus (notably IFN-γ) upregulate NOD2 expression and exacerbate inflammatory outputs specifically in mutant-NOD2 cells. (ueki2023tofacitinibasuppressor pages 1-2, ueki2023tofacitinibasuppressor pages 3-5)

3. Phenotypes (clinical features)

3.1 Core phenotypes and frequencies (recent cohort statistics)

The largest quantitative phenotype set in the retrieved evidence is a 47-patient pediatric cohort from a Chinese tertiary center (publication date May 2025). Key baseline frequencies: * Arthritis: 93.6% (44/47). (shi2025longtermprognosisof pages 1-2) * Rash/dermatitis: 72.3% (34/47). (shi2025longtermprognosisof pages 1-2) * Uveitis: 31.9%. (shi2025longtermprognosisof pages 1-2) * Fever: 34%. (shi2025longtermprognosisof pages 1-2) * Classic triad present: ~30%. (shi2025longtermprognosisof pages 1-2) * Vasculitis: 27.7%; interstitial lung disease: 17.0%; hypertension: 8.5%; cardiac enlargement: 6.4%; deafness: 6.4%; microscopic hematuria: 4.3%. (shi2025longtermprognosisof pages 1-2)

In this cohort, arthritis commonly involved ankles (90.9%), wrists (72.3%), and knees (70.2%) among those with arthritis. (shi2025longtermprognosisof pages 2-4)

A separate 13-patient Chinese cohort (10-year experience; publication date Feb 2026) reported: arthritis 100% (13/13), ocular involvement 92.3% (12/13), joint deformity 76.9% (10/13), and full triad 69.2% (9/13). (zhang2026clinicalfeaturestreatment pages 1-2)

3.2 Age of onset and course

Blau syndrome is typically early childhood-onset. In the 47-patient cohort, median onset was 13.64 months (range 1–51 months). (shi2025longtermprognosisof pages 1-2)

Progression can be organ-specific: skin manifestations may resolve in some individuals, while joint and eye disease can be progressive and lead to severe complications such as joint contracture and blindness (review-level statement). (matsuda2022potentialbenefitsof pages 1-2)

3.3 Quality-of-life impact

Visual morbidity is a major driver of disability: in a 2024 clinical genetics review/case series, >25% of patients were reported to suffer moderate-to-severe visual loss, although 10–20% may lack ocular involvement (review-level summary). (brichova2024blausyndromechallenging pages 1-2)

3.4 Suggested HPO terms (non-exhaustive)

(Provided as ontology suggestions for knowledge-base annotation) * Arthritis: HP:0001369 * Tenosynovitis / synovitis: HP:0100769 (synovitis) * Uveitis: HP:0000554 * Panuveitis: HP:0012113 * Granulomatous dermatitis: HP:0100710 (dermatitis) + modifier “granulomatous” (not always explicitly represented) * Rash: HP:0000988 * Fever: HP:0001945 * Interstitial lung disease: HP:0006530 * Vasculitis: HP:0002633 * Camptodactyly (commonly described in Blau): HP:0012385 (reported as ~60% in a recent review/case-series summary). (brichova2024blausyndromechallenging pages 1-2) * Hypertension: HP:0000822 * Hearing impairment: HP:0000365 * Hematuria: HP:0000790

4. Genetic / Molecular Information

4.1 Causal gene

NOD2 is the causal gene for Blau syndrome (dominant autoinflammatory granulomatous disease). (brichova2024blausyndromechallenging pages 1-2, shi2025longtermprognosisof pages 1-2)

4.2 Pathogenic variants and hotspots

A key practical point for molecular diagnosis is the NOD2 exon 4 hotspot, where the most recurrent Blau mutations occur. (brichova2024blausyndromechallenging pages 2-4)

Frequently cited pathogenic variants include: * NOD2 c.1001G>A p.(Arg334Gln) [R334Q] (brichova2024blausyndromechallenging pages 1-2) * NOD2 c.1000C>T p.(Arg334Trp) [R334W] (brichova2024blausyndromechallenging pages 1-2)

In the 47-patient Chinese cohort, 12 distinct NOD2 variants were identified; the authors report genotype–phenotype associations including that R334Q was associated with arthritis, rash, uveitis and fever, whereas R334W was associated with arthritis, rash and fever. (shi2025longtermprognosisof pages 1-2)

A 2024 case series emphasized that the pathogenicity interpretation of novel or VUS findings can be challenging, highlighting examples such as a novel NOD2 variant absent in gnomAD and an additional NLRC4 truncating VUS that likely did not explain the phenotype. (brichova2024blausyndromechallenging pages 6-8)

4.3 Variant classification and interpretation challenges

A 2024 diagnostic genetics case series used ACMG/AMP frameworks and highlighted difficulties in assigning causality when variants of uncertain significance (VUS) or dual diagnoses confound classic clinical interpretation. (brichova2024blausyndromechallenging pages 2-4, brichova2024blausyndromechallenging pages 8-10)

4.4 Functional consequences (current understanding)

Functional studies and reviews in the retrieved evidence emphasize that Blau-associated NOD2 mutations can cause ligand-independent/constitutive NF-κB transcriptional activity, consistent with gain-of-function inflammatory signaling. (matsuda2022potentialbenefitsof pages 1-2, ueki2023tofacitinibasuppressor pages 1-2)

5. Environmental Information

No reproducible external environmental/toxic/lifestyle risk factors were identified in the retrieved evidence set. The disease biology is primarily driven by Mendelian NOD2 variation, though immune stimuli (e.g., IFN-γ signaling) likely influence disease activity (see §6). (ueki2023tofacitinibasuppressor pages 1-2)

6. Mechanism / Pathophysiology

6.1 Upstream-to-downstream causal chain (evidence-supported)

Triggering context / priming: IFN-γ signaling increases NOD2 expression in myeloid cells; this appears to be an important “priming” step in cellular models of Blau syndrome. (matsuda2022potentialbenefitsof pages 4-6, ueki2023tofacitinibasuppressor pages 1-2)
Mutant receptor signaling: Blau-associated mutant NOD2 shows constitutive inflammatory signaling.
Abstract-level quote: Blau-associated NOD2 mutants “spontaneously promoted NF-kB transcription ... even without the addition of MDP” (i.e., ligand-independent). (matsuda2022potentialbenefitsof pages 1-2)
Cytokine amplification and granulomatous inflammation: In ex vivo/iPSC-derived models, inflammatory cytokine dysregulation in macrophages requires IFN-γ stimulation and can be corrected by anti-TNF therapy, implying a TNF-dependent amplification layer relevant to granulomatous pathology. (matsuda2022potentialbenefitsof pages 1-2)

6.2 Key molecular pathways (annotatable)

NF-κB activation downstream of NOD2 and associated cytokine programs. (matsuda2022potentialbenefitsof pages 1-2, ueki2023tofacitinibasuppressor pages 1-2)
IFN-γ → JAK/STAT signaling as an upstream regulator of NOD2 expression and inflammatory mediator induction in mutant cells. (ueki2023tofacitinibasuppressor pages 1-2, ueki2023tofacitinibasuppressor pages 3-5)
TNF-mediated inflammatory signaling as a therapeutically actionable node supported by ex vivo correction and cohort-level clinical experience. (matsuda2022potentialbenefitsof pages 1-2, shi2025longtermprognosisof pages 1-2)

6.3 Immune cells and tissues (cell ontology suggestions)

Evidence in the retrieved set supports a central role for macrophage-lineage myeloid cells in mechanistic assays (patient iPSC-derived monocytic/macrophage-like cells) and granulomatous inflammation. (ueki2023tofacitinibasuppressor pages 3-5, matsuda2022potentialbenefitsof pages 1-2)

Suggested CL terms (ontology suggestions): * Macrophage: CL:0000235 * Monocyte: CL:0000576 * Neutrophil: CL:0000775 (supported indirectly by tear proteomics neutrophil granule signature in severe ocular disease). (galozzi2024proteomicprofilingof pages 1-2, galozzi2024proteomicprofilingof pages 4-6)

6.4 GO biological process suggestions (ontology suggestions)

NF-κB signaling: GO:0043122 (regulation of I-kappaB kinase/NF-kappaB signaling)
Response to interferon-gamma: GO:0034341
Cytokine-mediated signaling pathway: GO:0019221
Granuloma formation: can be proxied by terms related to “inflammatory response” (GO:0006954) and macrophage activation.

6.5 Recent mechanistic developments (2023–2024 priority)

JAK inhibition as upstream control of NOD2 expression: A 2023 mechanistic study tested tofacitinib in mutant-NOD2 contexts and concluded that it suppresses IFN-γ-induced NOD2 expression and downstream cytokines rather than directly shutting off mutant NOD2’s basal NF-κB activity. * Abstract quote: “Tofacitinib did not suppress the increased spontaneous transcriptional activity of NF-kB by mutant NOD2.” (ueki2023tofacitinibasuppressor pages 1-2) * Abstract quote: IFN-γ induction “led to the production of inflammatory cytokines by an autoinflammatory mechanism only in cells with mutant NOD2.” (ueki2023tofacitinibasuppressor pages 1-2)

7. Anatomical Structures Affected

7.1 Organ systems (evidence-supported)

Joints / synovium / tendon sheaths: high-frequency arthritis/tenosynovitis. (shi2025longtermprognosisof pages 1-2)
Eye / uvea / retina-choroid: uveitis and panuveitis; a major morbidity driver. (brichova2024blausyndromechallenging pages 4-6, shi2025longtermprognosisof pages 1-2)
Skin: granulomatous dermatitis/rash. (shi2025longtermprognosisof pages 1-2)
Lung: interstitial lung disease in a subset (17% in one cohort). (shi2025longtermprognosisof pages 1-2)
Vascular system: vasculitis in a subset (27.7% in one cohort). (shi2025longtermprognosisof pages 1-2)
Kidney/urinary: microscopic hematuria in a subset; renal involvement is discussed in multisystem descriptions. (shi2025longtermprognosisof pages 1-2, brichova2024blausyndromechallenging pages 4-6)

7.2 UBERON term suggestions (ontology suggestions)

Synovial joint: UBERON:0000169
Uvea: UBERON:0001769
Skin: UBERON:0002097
Lung: UBERON:0002048
Kidney: UBERON:0002113

8. Temporal Development

8.1 Onset

Clinical manifestations often begin before age 4 (review-level) and can begin in infancy (median 13.64 months in the pediatric cohort). (brichova2024blausyndromechallenging pages 1-2, shi2025longtermprognosisof pages 1-2)

8.2 Progression patterns

The disease course is typically chronic with progressive risk for joint deformity and ocular complications; a 13-patient cohort reported joint deformity in 76.9%. (zhang2026clinicalfeaturestreatment pages 1-2)

9. Inheritance and Population

9.1 Inheritance

Autosomal dominant inheritance is typical; de novo/sporadic cases occur. * In the 47-patient pediatric cohort: familial 17% and sporadic 83%. (shi2025longtermprognosisof pages 2-4)

9.2 Epidemiology

Population prevalence/incidence estimates were not available in the retrieved evidence set (common limitation for ultra-rare Mendelian autoinflammatory diseases).

9.3 Sex ratio and demographics

In the 47-patient cohort, 26/47 were male and 21/47 female. (shi2025longtermprognosisof pages 1-2)

10. Diagnostics

10.1 Clinical criteria and confirmatory testing

Diagnosis is typically based on: 1. Clinical triad (dermatitis + arthritis/tenosynovitis + uveitis), and/or 2. Histopathology demonstrating non-caseating granulomas, and 3. Genetic confirmation of a pathogenic NOD2 variant. (shi2025longtermprognosisof pages 1-2, brichova2024blausyndromechallenging pages 2-4)

10.2 Genetic testing approach (real-world practice)

A practical approach used in a 2024 case series was to perform targeted Sanger sequencing of the NOD2 exon 4 hotspot in probands, supplemented by broader autoinflammatory gene panels and exome sequencing in select cases (e.g., atypical presentations, VUS, or phenocopies). (brichova2024blausyndromechallenging pages 2-4)

10.3 Diagnostic delays and misdiagnosis

Diagnostic delay is substantial: * Pediatric cohort: median diagnosis ~54.9 months with ~41.2 months delay. (shi2025longtermprognosisof pages 2-4) * 2024 case series: delays of 2–23 years (mean 9), with misdiagnosis as atopic dermatitis or juvenile idiopathic arthritis noted. (brichova2024blausyndromechallenging pages 11-13)

10.4 Differential diagnosis (evidence-based examples)

The 2024 diagnostic genetics report highlights challenges distinguishing Blau syndrome from other granulomatous or inflammatory conditions and emphasizes that biopsy and careful genetic interpretation may be required in atypical cases (e.g., neurological features mimicking neurosarcoidosis). (brichova2024blausyndromechallenging pages 2-4, brichova2024blausyndromechallenging pages 1-2)

10.5 Biomarkers and omics-based diagnostics (2024 development)

Tear proteomics (Aug 2024, IJMS) provides a candidate biomarker direction for ocular involvement. * 387 tear proteins identified; differential expression defined using fold-change thresholds and multiple testing correction. (galozzi2024proteomicprofilingof pages 2-4) * Candidate biomarkers upregulated in Blau vs controls include A2M and IGHG4 (e.g., IGHG4 FC ~10; A2M FC ~5–6.7 depending on comparison). (galozzi2024proteomicprofilingof pages 4-6) * In severe ocular disease, neutrophil granule proteins were markedly elevated compared with milder cases (e.g., MPO FC 16.50; AZU1 FC 24.84; DEFA3 FC 9.93). (galozzi2024proteomicprofilingof pages 4-6)

11. Outcome / Prognosis

11.1 Disease control rates under current treatment (cohort statistic)

In the 47-patient cohort, 72.3% achieved disease control at latest follow-up; TNF-α inhibitor-treated patients had higher remission rates (association reported in the cohort). (shi2025longtermprognosisof pages 1-2)

11.2 Major complications

Ocular involvement is a major morbidity driver with risk of vision loss (review-level). (brichova2024blausyndromechallenging pages 1-2)

Mortality and life expectancy statistics were not available in the retrieved evidence set.

12. Treatment

12.1 Current real-world management (cohort-based)

From the 47-patient pediatric cohort (May 2025): * Prednisolone + methotrexate: used in 95.7% (45/47). (shi2025longtermprognosisof pages 1-2) * TNF-α inhibitors: used in 42.6% (20/47). (shi2025longtermprognosisof pages 1-2) * Disease control at follow-up: 72.3% (34/47), with higher remission in TNFi-treated patients. (shi2025longtermprognosisof pages 1-2)

A 13-patient cohort described high TNFi uptake (12/13) with initial complete remissions on infliximab/etanercept/adalimumab in subsets and frequent relapse/secondary loss of efficacy over time (46.2% relapse/secondary loss reported). (zhang2026clinicalfeaturestreatment pages 1-2)

12.2 Mechanism-based therapeutic rationale (authoritative review)

A mechanistic review concluded that although multiple therapies (IL-1, IL-6, JAK inhibitors) have been reported, anti-TNF therapy plays a central role. (matsuda2022potentialbenefitsof pages 1-2)

Ex vivo mechanistic support: * “abnormal cytokine expression in macrophages … requires IFNg stimulation,” and “anti-TNF treatment corrects the abnormalities … even in the presence of IFNg.” (matsuda2022potentialbenefitsof pages 1-2)

12.3 Recent developments (2023–2024 priority)

JAK inhibitors / tofacitinib mechanistic study (Jun 2023): supports upstream blockade of IFN-γ-induced NOD2 expression and cytokines. * Quote: “Tofacitinib did not suppress the increased spontaneous transcriptional activity of NF-kB by mutant NOD2.” (ueki2023tofacitinibasuppressor pages 1-2) * Quote: Tofacitinib suppressed IFN-γ-induced NOD2 induction “thereby inhibiting the production of pro-inflammatory cytokines.” (ueki2023tofacitinibasuppressor pages 1-2)

Biomarker development (Aug 2024): tear proteomics identifies candidate ocular biomarkers and highlights neutrophil granule proteins in severe disease. (galozzi2024proteomicprofilingof pages 4-6)

12.4 Experimental/clinical trials (ClinicalTrials.gov)

NCT06660329 (posted 2024; start 2024-10-01): “Efficacy and Safety of Tofacitinib in Refractory Blau Syndrome,” Phase 4, open-label single-group, estimated n=30 pediatric participants; primary outcome is remission/low disease activity at 6 months; includes longitudinal inflammatory markers/cytokines including TNFα and IFNγ. URL: https://clinicaltrials.gov/study/NCT06660329 (NCT06660329 chunk 1)
NCT06688838 (posted 2024-11-14): retrospective cohort comparing glucocorticoid+DMARDs vs +TNFi vs +tofacitinib, estimated n=24. URL: https://clinicaltrials.gov/study/NCT06688838 (NCT06688838 chunk 1)

12.5 MAXO term suggestions (ontology suggestions)

Systemic glucocorticoid therapy
Methotrexate therapy
Tumor necrosis factor inhibitor therapy
Janus kinase inhibitor therapy
Interleukin-1 inhibitor therapy
Interleukin-6 receptor inhibitor therapy
Ophthalmologic monitoring and uveitis-directed therapy

13. Prevention

Because Blau syndrome is a Mendelian dominant disorder, prevention focuses on genetic counseling and cascade testing in families with known pathogenic NOD2 variants; no primary prevention strategies are established in the retrieved evidence set. (brichova2024blausyndromechallenging pages 2-4)

14. Other Species / Natural Disease

No naturally occurring non-human Blau syndrome analogs were identified in the retrieved evidence set.

15. Model Organisms / Experimental Models

15.1 Human cell models (strongest evidence in retrieved set)

A 2023 mechanistic study used patient-derived induced pluripotent stem cell (iPSC)–derived monocytic/myeloid cells to test IFN-γ induction of NOD2 and cytokine production and to examine tofacitinib effects. (ueki2023tofacitinibasuppressor pages 3-5, ueki2023tofacitinibasuppressor pages 1-2)

15.2 Suggested model utility

Such iPSC-derived myeloid models are useful for: * probing IFN-γ–priming of mutant-NOD2 inflammatory outputs; * testing JAK inhibition as a strategy to block cytokine-driven induction of NOD2 expression. (ueki2023tofacitinibasuppressor pages 3-5, ueki2023tofacitinibasuppressor pages 1-2)

Key visual evidence

The 2024 Genes case series includes a family-variant figure and a clinical feature table useful for knowledge-base validation and phenotype capture. (brichova2024blausyndromechallenging media 5971238a, brichova2024blausyndromechallenging media 2378c737)

Structured summary table

Domain	Key points (with quantitative data where available)	Best recent source (first author year)	URL
Definition / triad	Rare pediatric autoinflammatory granulomatous disease defined by the classic triad of granulomatous dermatitis, symmetric arthritis/tenosynovitis, and recurrent uveitis; early-onset sarcoidosis is generally considered the sporadic counterpart (brichova2024blausyndromechallenging pages 1-2, shi2025longtermprognosisof pages 1-2)	Brichova 2024	https://doi.org/10.3390/genes15060799
Inheritance	Usually autosomal dominant due to heterozygous gain-of-function NOD2 variants; Chinese pediatric cohort: 17% familial and 83% sporadic/de novo among 47 cases (brichova2024blausyndromechallenging pages 1-2, shi2025longtermprognosisof pages 2-4)	Brichova 2024	https://doi.org/10.3390/genes15060799
Onset age	Clinical manifestations typically begin before age 3–4 years; Chinese cohort median onset 13.64 months (range 1–51 months) (brichova2024blausyndromechallenging pages 1-2, shi2025longtermprognosisof pages 1-2)	Shi 2025	https://doi.org/10.1186/s12887-025-05584-x
Key phenotype frequencies (Shi cohort, n=47)	Arthritis 93.6% (44/47); rash/dermatitis 72.3% (34/47); fever 34%; uveitis 31.9%; full triad in ~30%; vasculitis 27.7%; interstitial lung disease 17.0%; hypertension 8.5%; cardiac enlargement 6.4%; deafness 6.4%; microscopic hematuria 4.3% (shi2025longtermprognosisof pages 1-2, shi2025longtermprognosisof pages 2-4)	Shi 2025	https://doi.org/10.1186/s12887-025-05584-x
Diagnostic delay	Chinese cohort: median diagnosis age 54.9 months with median diagnostic delay ~41.2 months; 2024 Czech series reports delays of 2–23 years (mean 9 years), underscoring frequent under-recognition/misdiagnosis (shi2025longtermprognosisof pages 2-4, brichova2024blausyndromechallenging pages 11-13)	Shi 2025	https://doi.org/10.1186/s12887-025-05584-x
Causal gene / hotspot variants	Causal gene: NOD2 (CARD15). Exon 4 is a mutational hotspot; p.Arg334Gln (R334Q) and p.Arg334Trp (R334W) are the best-known recurrent pathogenic variants. In the Chinese cohort, R334Q correlated with arthritis, rash, uveitis, fever; R334W with arthritis, rash, fever (brichova2024blausyndromechallenging pages 2-4, shi2025longtermprognosisof pages 1-2)	Brichova 2024	https://doi.org/10.3390/genes15060799
Mechanism	Core mechanism: Blau-associated NOD2 mutants show constitutive/ligand-independent NF-κB activation; IFN-γ acts as a priming signal by upregulating NOD2 in patient macrophage models; anti-TNF can correct IFN-γ-associated cytokine abnormalities ex vivo, supporting TNF dependence in downstream inflammation/granuloma biology (matsuda2022potentialbenefitsof pages 1-2, matsuda2022potentialbenefitsof pages 4-6, ueki2023tofacitinibasuppressor pages 1-2)	Ueki 2023	https://doi.org/10.3389/fimmu.2023.1211240
Treatment outcomes	In the 47-patient Chinese cohort, 95.7% (45/47) received prednisolone + methotrexate and 42.6% (20/47) received TNF inhibitors; 72.3% (34/47) achieved disease control at last follow-up, with higher remission rates in TNFi-treated patients (shi2025longtermprognosisof pages 1-2)	Shi 2025	https://doi.org/10.1186/s12887-025-05584-x
JAK inhibitor rationale	Tofacitinib did not suppress mutant-NOD2-driven basal NF-κB directly, but it suppressed IFN-γ-induced NOD2 expression and reduced downstream pro-inflammatory cytokine production in Blau iPSC-derived myeloid cells; this provides an upstream mechanistic rationale for JAK inhibition in refractory disease (ueki2023tofacitinibasuppressor pages 1-2, ueki2023tofacitinibasuppressor pages 3-5)	Ueki 2023	https://doi.org/10.3389/fimmu.2023.1211240
Tear proteomics / biomarkers	2024 tear proteomics identified 387 proteins. In affected p.E383K carriers, A2M and IGHG4 were highlighted as candidate biomarkers; quantitative examples include A2M FC 5.03 (vs unaffected family) and 6.75 (vs controls), IGHG4 FC ~10.17 and ~10.28, haptoglobin FC 5.71, SERPINA3 FC 5.71. In the most severe ocular case, neutrophil-granule proteins were elevated, including MPO FC 16.50, AZU1 FC 24.84, DEFA3 FC 9.93 (galozzi2024proteomicprofilingof pages 1-2, galozzi2024proteomicprofilingof pages 2-4, galozzi2024proteomicprofilingof pages 4-6, galozzi2024proteomicprofilingof pages 12-14)	Galozzi 2024	https://doi.org/10.3390/ijms25158387

Table: This table condenses the most actionable facts for Blau syndrome across definition, genetics, mechanism, phenotype frequencies, and treatment response. It emphasizes recent cohort and mechanistic studies that are useful for rapid knowledge-base population.

Limitations of this report (evidence availability)

Prevalence/incidence estimates and mortality/life expectancy were not available in the retrieved documents.
MONDO/Orphanet/ICD/MeSH identifiers were not retrievable from the current evidence set and should be added via dedicated ontology lookups.
PMIDs were not provided in the extracted tool context for these papers; DOI and publication dates are provided where available in-source.

References

(brichova2024blausyndromechallenging pages 1-2): Michaela Brichova, Aneta Klimova, Jarmila Heissigerova, Petra Svozilkova, Manuela Vaneckova, Pavla Dolezalova, Dana Nemcova, Marcela Michalickova, Jana Jedlickova, Lubica Dudakova, and Petra Liskova. Blau syndrome: challenging molecular genetic diagnostics of autoinflammatory disease. Genes, 15:799, Jun 2024. URL: https://doi.org/10.3390/genes15060799, doi:10.3390/genes15060799. This article has 4 citations.
(shi2025longtermprognosisof pages 1-2): Xinwei Shi, Jianghong Deng, Junmei Zhang, Xiaozhen Zhao, Yinan Zhao, Li Li, Fengqiao Gao, Weiying Kuang, Jiang Wang, Xiaohua Tan, Chao Li, Shipeng Li, and Caifeng Li. Long-term prognosis of 47 pediatric patients with blau syndrome in china. BMC Pediatrics, May 2025. URL: https://doi.org/10.1186/s12887-025-05584-x, doi:10.1186/s12887-025-05584-x. This article has 2 citations and is from a peer-reviewed journal.
(NCT06660329 chunk 1): Hongmei Song. Efficacy and Safety of Tofacitinib in Refractory Blau Syndrome. Peking Union Medical College Hospital. 2024. ClinicalTrials.gov Identifier: NCT06660329
(zhang2026clinicalfeaturestreatment pages 9-10): Jingyuan Zhang and Min Shen. Clinical features, treatment strategies, and long-term outcomes of blau syndrome: a 10-year experience from a chinese cohort. Advances in Rheumatology, Feb 2026. URL: https://doi.org/10.1186/s42358-026-00528-0, doi:10.1186/s42358-026-00528-0. This article has 0 citations.
(brichova2024blausyndromechallenging pages 11-13): Michaela Brichova, Aneta Klimova, Jarmila Heissigerova, Petra Svozilkova, Manuela Vaneckova, Pavla Dolezalova, Dana Nemcova, Marcela Michalickova, Jana Jedlickova, Lubica Dudakova, and Petra Liskova. Blau syndrome: challenging molecular genetic diagnostics of autoinflammatory disease. Genes, 15:799, Jun 2024. URL: https://doi.org/10.3390/genes15060799, doi:10.3390/genes15060799. This article has 4 citations.
(matsuda2022potentialbenefitsof pages 1-2): Tomoko Matsuda, Naotomo Kambe, Riko Takimoto-Ito, Yoko Ueki, Satoshi Nakamizo, Megumu K. Saito, Syuji Takei, and Nobuo Kanazawa. Potential benefits of tnf targeting therapy in blau syndrome, a nod2-associated systemic autoinflammatory granulomatosis. Frontiers in Immunology, May 2022. URL: https://doi.org/10.3389/fimmu.2022.895765, doi:10.3389/fimmu.2022.895765. This article has 27 citations and is from a peer-reviewed journal.
(ueki2023tofacitinibasuppressor pages 1-2): Yoko Ueki, Riko Takimoto-Ito, Megumu K. Saito, Hideaki Tanizaki, and Naotomo Kambe. Tofacitinib, a suppressor of nod2 expression, is a potential treatment for blau syndrome. Frontiers in Immunology, Jun 2023. URL: https://doi.org/10.3389/fimmu.2023.1211240, doi:10.3389/fimmu.2023.1211240. This article has 16 citations and is from a peer-reviewed journal.
(brichova2024blausyndromechallenging pages 2-4): Michaela Brichova, Aneta Klimova, Jarmila Heissigerova, Petra Svozilkova, Manuela Vaneckova, Pavla Dolezalova, Dana Nemcova, Marcela Michalickova, Jana Jedlickova, Lubica Dudakova, and Petra Liskova. Blau syndrome: challenging molecular genetic diagnostics of autoinflammatory disease. Genes, 15:799, Jun 2024. URL: https://doi.org/10.3390/genes15060799, doi:10.3390/genes15060799. This article has 4 citations.
(ueki2023tofacitinibasuppressor pages 3-5): Yoko Ueki, Riko Takimoto-Ito, Megumu K. Saito, Hideaki Tanizaki, and Naotomo Kambe. Tofacitinib, a suppressor of nod2 expression, is a potential treatment for blau syndrome. Frontiers in Immunology, Jun 2023. URL: https://doi.org/10.3389/fimmu.2023.1211240, doi:10.3389/fimmu.2023.1211240. This article has 16 citations and is from a peer-reviewed journal.
(shi2025longtermprognosisof pages 2-4): Xinwei Shi, Jianghong Deng, Junmei Zhang, Xiaozhen Zhao, Yinan Zhao, Li Li, Fengqiao Gao, Weiying Kuang, Jiang Wang, Xiaohua Tan, Chao Li, Shipeng Li, and Caifeng Li. Long-term prognosis of 47 pediatric patients with blau syndrome in china. BMC Pediatrics, May 2025. URL: https://doi.org/10.1186/s12887-025-05584-x, doi:10.1186/s12887-025-05584-x. This article has 2 citations and is from a peer-reviewed journal.
(zhang2026clinicalfeaturestreatment pages 1-2): Jingyuan Zhang and Min Shen. Clinical features, treatment strategies, and long-term outcomes of blau syndrome: a 10-year experience from a chinese cohort. Advances in Rheumatology, Feb 2026. URL: https://doi.org/10.1186/s42358-026-00528-0, doi:10.1186/s42358-026-00528-0. This article has 0 citations.
(brichova2024blausyndromechallenging pages 6-8): Michaela Brichova, Aneta Klimova, Jarmila Heissigerova, Petra Svozilkova, Manuela Vaneckova, Pavla Dolezalova, Dana Nemcova, Marcela Michalickova, Jana Jedlickova, Lubica Dudakova, and Petra Liskova. Blau syndrome: challenging molecular genetic diagnostics of autoinflammatory disease. Genes, 15:799, Jun 2024. URL: https://doi.org/10.3390/genes15060799, doi:10.3390/genes15060799. This article has 4 citations.
(brichova2024blausyndromechallenging pages 8-10): Michaela Brichova, Aneta Klimova, Jarmila Heissigerova, Petra Svozilkova, Manuela Vaneckova, Pavla Dolezalova, Dana Nemcova, Marcela Michalickova, Jana Jedlickova, Lubica Dudakova, and Petra Liskova. Blau syndrome: challenging molecular genetic diagnostics of autoinflammatory disease. Genes, 15:799, Jun 2024. URL: https://doi.org/10.3390/genes15060799, doi:10.3390/genes15060799. This article has 4 citations.
(matsuda2022potentialbenefitsof pages 4-6): Tomoko Matsuda, Naotomo Kambe, Riko Takimoto-Ito, Yoko Ueki, Satoshi Nakamizo, Megumu K. Saito, Syuji Takei, and Nobuo Kanazawa. Potential benefits of tnf targeting therapy in blau syndrome, a nod2-associated systemic autoinflammatory granulomatosis. Frontiers in Immunology, May 2022. URL: https://doi.org/10.3389/fimmu.2022.895765, doi:10.3389/fimmu.2022.895765. This article has 27 citations and is from a peer-reviewed journal.
(galozzi2024proteomicprofilingof pages 1-2): Paola Galozzi, Sara Bindoli, Chiara Baggio, Ilaria Battisti, Andrea Leonardi, Daniela Basso, Giorgio Arrigoni, and Paolo Sfriso. Proteomic profiling of tears in blau syndrome patients in identification of potential disease biomarkers. International Journal of Molecular Sciences, 25:8387, Aug 2024. URL: https://doi.org/10.3390/ijms25158387, doi:10.3390/ijms25158387. This article has 2 citations.
(galozzi2024proteomicprofilingof pages 4-6): Paola Galozzi, Sara Bindoli, Chiara Baggio, Ilaria Battisti, Andrea Leonardi, Daniela Basso, Giorgio Arrigoni, and Paolo Sfriso. Proteomic profiling of tears in blau syndrome patients in identification of potential disease biomarkers. International Journal of Molecular Sciences, 25:8387, Aug 2024. URL: https://doi.org/10.3390/ijms25158387, doi:10.3390/ijms25158387. This article has 2 citations.
(brichova2024blausyndromechallenging pages 4-6): Michaela Brichova, Aneta Klimova, Jarmila Heissigerova, Petra Svozilkova, Manuela Vaneckova, Pavla Dolezalova, Dana Nemcova, Marcela Michalickova, Jana Jedlickova, Lubica Dudakova, and Petra Liskova. Blau syndrome: challenging molecular genetic diagnostics of autoinflammatory disease. Genes, 15:799, Jun 2024. URL: https://doi.org/10.3390/genes15060799, doi:10.3390/genes15060799. This article has 4 citations.
(galozzi2024proteomicprofilingof pages 2-4): Paola Galozzi, Sara Bindoli, Chiara Baggio, Ilaria Battisti, Andrea Leonardi, Daniela Basso, Giorgio Arrigoni, and Paolo Sfriso. Proteomic profiling of tears in blau syndrome patients in identification of potential disease biomarkers. International Journal of Molecular Sciences, 25:8387, Aug 2024. URL: https://doi.org/10.3390/ijms25158387, doi:10.3390/ijms25158387. This article has 2 citations.
(NCT06688838 chunk 1): YIKAI YU. Effective Treatment of Jak1/3 Inhibitor in Blau Syndrome. Tongji Hospital. 2017. ClinicalTrials.gov Identifier: NCT06688838
(brichova2024blausyndromechallenging media 5971238a): Michaela Brichova, Aneta Klimova, Jarmila Heissigerova, Petra Svozilkova, Manuela Vaneckova, Pavla Dolezalova, Dana Nemcova, Marcela Michalickova, Jana Jedlickova, Lubica Dudakova, and Petra Liskova. Blau syndrome: challenging molecular genetic diagnostics of autoinflammatory disease. Genes, 15:799, Jun 2024. URL: https://doi.org/10.3390/genes15060799, doi:10.3390/genes15060799. This article has 4 citations.
(brichova2024blausyndromechallenging media 2378c737): Michaela Brichova, Aneta Klimova, Jarmila Heissigerova, Petra Svozilkova, Manuela Vaneckova, Pavla Dolezalova, Dana Nemcova, Marcela Michalickova, Jana Jedlickova, Lubica Dudakova, and Petra Liskova. Blau syndrome: challenging molecular genetic diagnostics of autoinflammatory disease. Genes, 15:799, Jun 2024. URL: https://doi.org/10.3390/genes15060799, doi:10.3390/genes15060799. This article has 4 citations.
(galozzi2024proteomicprofilingof pages 12-14): Paola Galozzi, Sara Bindoli, Chiara Baggio, Ilaria Battisti, Andrea Leonardi, Daniela Basso, Giorgio Arrigoni, and Paolo Sfriso. Proteomic profiling of tears in blau syndrome patients in identification of potential disease biomarkers. International Journal of Molecular Sciences, 25:8387, Aug 2024. URL: https://doi.org/10.3390/ijms25158387, doi:10.3390/ijms25158387. This article has 2 citations.

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Blau Syndrome (Mendelian) — Comprehensive Disease Characteristics Report

1. Disease Information

1.1 Overview (current understanding)

1.2 Key identifiers (best available from retrieved sources)

1.3 Synonyms / alternative names

2. Etiology

2.1 Disease causal factors

2.2 Risk factors

2.3 Protective factors

2.4 Gene–environment interactions

3. Phenotypes (clinical features)

3.1 Core phenotypes and frequencies (recent cohort statistics)

3.2 Age of onset and course

3.3 Quality-of-life impact

3.4 Suggested HPO terms (non-exhaustive)

4. Genetic / Molecular Information

4.1 Causal gene

4.2 Pathogenic variants and hotspots

4.3 Variant classification and interpretation challenges

4.4 Functional consequences (current understanding)

5. Environmental Information

6. Mechanism / Pathophysiology

6.1 Upstream-to-downstream causal chain (evidence-supported)

6.2 Key molecular pathways (annotatable)

6.3 Immune cells and tissues (cell ontology suggestions)

6.4 GO biological process suggestions (ontology suggestions)

6.5 Recent mechanistic developments (2023–2024 priority)

7. Anatomical Structures Affected

7.1 Organ systems (evidence-supported)

7.2 UBERON term suggestions (ontology suggestions)

8. Temporal Development

8.1 Onset

8.2 Progression patterns

9. Inheritance and Population

9.1 Inheritance

9.2 Epidemiology

9.3 Sex ratio and demographics

10. Diagnostics

10.1 Clinical criteria and confirmatory testing

10.2 Genetic testing approach (real-world practice)

10.3 Diagnostic delays and misdiagnosis

10.4 Differential diagnosis (evidence-based examples)

10.5 Biomarkers and omics-based diagnostics (2024 development)

11. Outcome / Prognosis

11.1 Disease control rates under current treatment (cohort statistic)

11.2 Major complications

12. Treatment

12.1 Current real-world management (cohort-based)

12.2 Mechanism-based therapeutic rationale (authoritative review)

12.3 Recent developments (2023–2024 priority)

12.4 Experimental/clinical trials (ClinicalTrials.gov)

12.5 MAXO term suggestions (ontology suggestions)

13. Prevention

14. Other Species / Natural Disease

15. Model Organisms / Experimental Models

15.1 Human cell models (strongest evidence in retrieved set)

15.2 Suggested model utility

Key visual evidence

Structured summary table

Limitations of this report (evidence availability)