DNASE2 Deficiency

Mendelian MONDO:0800132 Pathograph 24 Show in embeddings browser Type I Interferonopathy Autoinflammatory Disorder Inborn Errors of Immunity

DNASE2 deficiency is an autosomal recessive type I interferonopathy caused by biallelic loss-of-function variants in DNASE2, which encodes deoxyribonuclease II, the acid endonuclease that digests DNA inside lysosomes. Macrophages rely on it to degrade the nuclei expelled by maturing erythroblasts and the chromatin of engulfed apoptotic cells. When it fails, undigested self DNA engages the cGAS-STING DNA-sensing pathway, and the result is constitutive type I interferon production with a high interferon-stimulated gene signature, plus an interferon-independent proinflammatory cytokine arm. The presentation is neonatal: severe non-regenerative anemia and thrombocytopenia needing transfusion, hepatosplenomegaly and cholestatic hepatitis, sometimes beginning before birth with fetal anemia and hydrops. In the published patients the neonatal cytopenias resolved over weeks to months and were followed in childhood by recurrent fevers, membranoproliferative glomerulonephritis with proteinuria, hepatic fibrosis, a deforming arthropathy with contractures, vasculitic and nodular skin lesions, chilblain-like lesions, lipodystrophy, anti-DNA autoantibodies and failure to thrive. Two of the three index patients had subcortical white matter lesions on MRI with learning difficulties. Fewer than fifteen patients are reported. JAK1/2 inhibition has been followed by clinical improvement in several of them.

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1
Inheritance
8
Pathophys.
25
Phenotypes
24
Pathograph
1
Genes
3
Medical Actions
2
Models
1
References
1
Deep Research
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Classifications

Harrison's Part
IMMUNE RHEUMATOLOGIC GENETICS ENVIRONMENT DISEASE
IUIS Category
autoinflammatory syndrome
👪

Inheritance

1
Autosomal recessive inheritance HP:0000007
Affected individuals are homozygous or compound heterozygous for DNASE2 loss-of-function alleles, and parents tested in the index families were heterozygous carriers.
Autosomal recessive inheritance
Show evidence (2 references)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Both sets of parents were heterozygous for the relevant familial variant, and all four unaffected siblings from both families were either homozygous or heterozygous wild type"
Segregation in the two index families fits autosomal recessive inheritance.
PMID:42491852 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Whole-exome sequencing identified two novel heterozygous variants in the Dnase2 gene (p.Gly48AlafsTer49 and p.Met1), consistent with a compound heterozygous state"
A compound heterozygous genotype in a child of non-consanguineous parents, also consistent with recessive inheritance.
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Pathophysiology

8
Biallelic DNASE2 Loss of Function
Biallelic DNASE2 variants abolish or sharply reduce the activity of DNase II, a lysosomal acid endonuclease. In the index families the missense and exon 4-skipping alleles left little or no measurable activity against plasmid DNA when expressed in HEK293T cells, and patient fibroblast lysates had markedly reduced activity that wild-type DNASE2 restored. This is the lysosomal-hydrolase substitution at the trigger node of the lysosomal substrate accumulation module; the stored substrate is DNA.
DNASE2 hgnc:2960 HUGO Gene Nomenclature Committee (hgnc) Relation: this pathophysiological event involves this gene This pathophysiological event involves DNASE2 (hgnc:2960). hgnc:2960 is a gene from the HUGO Gene Nomenclature Committee.
Genetic context variant_origin: GERMLINE functional_impact_category: LOSS_OF_FUNCTION
deoxyribonuclease II activity GO:0004531 ↓ DECREASED Gene Ontology (GO) Relation: this pathophysiological event involves this molecular function This pathophysiological event involves decreased deoxyribonuclease II activity (GO:0004531). GO:0004531 is a molecular function from the Gene Ontology.
Downstream
Undegraded DNA Accumulation in Macrophage Lysosomes Without DNase II, macrophages that engulf erythroblast nuclei and apoptotic cells cannot digest their DNA.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT In Vitro
"Expression in HEK293T cells of mutant constructs lacking exon 4, or with the c.347G>C (Gly116Ala) or the c.362A>T (Asp121Val) substitutions, was associated with reduced levels of DNase II activity against circularized plasmid DNA compared to controls"
Recombinant expression of the patient alleles shows the loss of nuclease activity.
Undegraded DNA Accumulation in Macrophage Lysosomes
Macrophages at sites of definitive erythropoiesis (fetal liver Kupffer cells, bone marrow macrophages) and at sites of developmental apoptosis engulf expelled erythroid nuclei and apoptotic cells but cannot digest their chromatin, which accumulates as undigested DNA in their lysosomes. Unlike the classical lysosomal storage diseases, the damage that follows is driven by innate immune sensing of the stored DNA rather than by storage cytotoxicity, so this entry conforms only to the first two nodes of the lysosomal module.
macrophage CL:0000235 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves macrophage (CL:0000235). CL:0000235 is a cell type from the Cell Ontology. Kupffer cell CL:0000091 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves Kupffer cell (CL:0000091). CL:0000091 is a cell type from the Cell Ontology.
DNA catabolic process GO:0006308 ↓ DECREASED Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased DNA catabolic process (GO:0006308). GO:0006308 is a biological process from the Gene Ontology.
Downstream
cGAS-STING Activation by Undegraded Self DNA
Endosomal TLR-Dependent Anti-Nucleic Acid Autoantibody Production
AIM2 Inflammasome Activation in Inflamed Joints
Show evidence (2 references)
PMID:15568025 SUPPORT DIRECT PRIMARY RESULT Model Organism
"The livers of DNase II-deficient mouse embryos contain many macrophages carrying undigested DNA, and the embryos die in utero."
Direct observation of DNA-laden macrophages in DNase II-null fetal liver.
PMID:29259162 SUPPORT DIRECT BACKGROUND Model Organism
"DNase II null mice accumulate DNA in the lysosomes of fetal liver Kupffer cells and bone marrow macrophages"
Summarizes the mouse work on the lysosomal location of the stored DNA in Kupffer cells and bone marrow macrophages. The quote is the human paper's restatement of earlier mouse studies, hence BACKGROUND.
cGAS-STING Activation by Undegraded Self DNA
DNA that escapes lysosomal degradation is detected by cGAS, which synthesizes cGAMP and activates STING. This is the DNASE2-specific substitution at the module's entry node: the DNA reaches cGAS from a failed lysosomal digestion rather than from loss of a cytosolic nuclease such as TREX1. The route by which lysosomal DNA reaches cytosolic cGAS is not established in the cited sources. The pathway dependence is shown genetically in mice: cGAMP accumulates in DNase II-deficient tissues in a cGAS-dependent way, and deleting cGas or Sting rescues both the embryonic lethality and the arthritis.
macrophage CL:0000235 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves macrophage (CL:0000235). CL:0000235 is a cell type from the Cell Ontology.
cGAS/STING signaling pathway GO:0140896 ↑ INCREASED Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased cGAS/STING signaling pathway (GO:0140896). GO:0140896 is a biological process from the Gene Ontology.
2',3'-cyclic GMP-AMP synthase activity GO:0061501 ↑ INCREASED Gene Ontology (GO) Relation: this pathophysiological event involves this molecular function This pathophysiological event involves increased 2',3'-cyclic GMP-AMP synthase activity (GO:0061501). GO:0061501 is a molecular function from the Gene Ontology.
Downstream
Type I Interferon Overproduction and JAK-STAT Signaling
STING-TBK1-Driven Proinflammatory Cytokine Production
Show evidence (3 references)
PMID:26371324 SUPPORT DIRECT PRIMARY RESULT Model Organism
"Similarly, deletion of cGas in mice lacking DNaseII, a lysosomal enzyme that digests DNA, rescued the lethal autoimmune phenotypes of the DNaseII(-/-) mice."
Genetic rescue places cGAS downstream of DNase II loss.
PMID:26371324 SUPPORT DIRECT PRIMARY RESULT Model Organism
"we found that cGAMP accumulated in mouse tissues deficient in Trex1 or DNaseII and that this accumulation was dependent on cGAS"
cGAMP, the product of activated cGAS, is raised in DNase II-deficient tissue.
PMID:23132945 SUPPORT DIRECT PRIMARY RESULT Model Organism
"DNase II-dependent embryonic lethality was rescued by loss of STING function, and polyarthritis completely prevented"
STING deletion rescues both the embryonic and the postnatal DNase II phenotypes.
Type I Interferon Overproduction and JAK-STAT Signaling
Activated STING recruits TBK1 and drives IRF3-dependent transcription of type I interferons. In patients this shows as raised interferon alpha protein, a whole-blood interferon-stimulated gene signature like that of other type I interferonopathies, and constitutive STAT1 and STAT3 phosphorylation in unstimulated T cells and monocytes. The signaling is JAK-STAT dependent, which is the rationale for JAK inhibition.
monocyte CL:0000576 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves monocyte (CL:0000576). CL:0000576 is a cell type from the Cell Ontology.
positive regulation of type I interferon production GO:0032481 ↑ INCREASED Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased positive regulation of type I interferon production (GO:0032481). GO:0032481 is a biological process from the Gene Ontology. JAK-STAT signaling GO:0007259 ↑ INCREASED Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased JAK-STAT signaling, annotated with cell surface receptor signaling pathway via JAK-STAT (GO:0007259). GO:0007259 is a biological process from the Gene Ontology.
Downstream
Type I Interferon Signature
Interferon-Driven Suppression of Fetal and Neonatal Erythropoiesis
Membranoproliferative Glomerulonephritis
Hepatic Fibrosis
Vasculitis in the skin
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"We record increased interferon alpha protein levels using digital ELISA, enhanced interferon signaling by RNA-Seq analysis and constitutive upregulation of phosphorylated STAT1 and STAT3 in patient lymphocytes and monocytes."
Direct patient evidence for interferon overproduction and constitutive JAK-STAT signaling.
STING-TBK1-Driven Proinflammatory Cytokine Production
STING signaling also drives an interferon-independent proinflammatory cytokine arm. In patients the serum cytokine pattern overlaps that of STING gain-of-function disease, with raised TNF-alpha and variable IL-1beta and IL-6. Mouse work shows this arm runs through TBK1 recruitment to STING and NF-kB rather than through IRF3 and type I interferon: a STING mutant that cannot induce interferon still causes TNF- and IL-6-dependent polyarthritis. This arm is the likely driver of the deforming arthropathy.
tumor necrosis factor production GO:0032640 ↑ INCREASED Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased tumor necrosis factor production (GO:0032640). GO:0032640 is a biological process from the Gene Ontology.
Animal models
Dnase2 Ifnar1 double-knockout mouse Mus musculus recapitulates Reproduces the TNF-driven inflammatory arthritis of the interferon-independent arm.
Downstream
Deforming Arthropathy
Recurrent Fever
Show evidence (2 references)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"suggesting consistently elevated protein levels of TNFα in both patients, a more variable elevation of IL-1β, and concentrations of IL-6 mostly reflecting normal physiological levels"
The non-interferon cytokine pattern measured in patient serum.
PMID:34901991 SUPPORT INDIRECT PRIMARY RESULT Model Organism
"DNase II-/-STING-S365A mice exhibited severe polyarthritis, which was alleviated by neutralizing antibodies against TNF-α or IL-6 receptor"
A STING mutant unable to induce type I interferon still produces TNF- and IL-6-dependent arthritis, placing the arthritis on the interferon-independent STING-TBK1 arm. Indirect because it is a mouse genetic dissection rather than a human observation.
Interferon-Driven Suppression of Fetal and Neonatal Erythropoiesis
Type I interferon produced by DNA-laden macrophages acts on erythropoiesis. In DNase II-null mice interferon-beta from resident fetal liver macrophages causes a lethal anemia that is rescued by deleting the type I interferon receptor. In patients the neonatal anemia is non-regenerative with increased circulating erythroblasts and reticulocyte counts inappropriate for the hemoglobin, a picture of ineffective erythropoiesis, and recombinant interferon alpha increased apoptosis of cord-blood erythroid progenitors.
erythroblast CL:0000765 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves erythroblast (CL:0000765). CL:0000765 is a cell type from the Cell Ontology.
definitive erythrocyte differentiation GO:0060318 ↓ DECREASED Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased definitive erythrocyte differentiation (GO:0060318). GO:0060318 is a biological process from the Gene Ontology.
Animal models
Dnase2 knockout mouse Mus musculus recapitulates Reproduces the type I interferon-dependent failure of definitive erythropoiesis.
Downstream
Neonatal Anemia
Thrombocytopenia
Circulating nucleated red blood cells
Show evidence (3 references)
PMID:15568025 SUPPORT INDIRECT PRIMARY RESULT Model Organism
"When the DNase II-deficient mice were crossed with mice deficient in type I interferon receptor, the resultant 'double-mutant' mice were born healthy."
Deleting the interferon receptor rescues the lethal anemia, placing type I interferon causally upstream of the erythropoietic failure. Indirect because it is a mouse genetic result applied to the human neonatal anemia.
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Fresh blood samples from F1:V-1 and F1:V-3 demonstrated a marked increase in the percentage of circulating erythroblasts, whilst the number of reticulocytes was the same as in controls"
The circulating erythroblast increase with inappropriate reticulocytes in patients, indicating ineffective erythropoiesis.
PMID:29259162 SUPPORT INDIRECT PRIMARY RESULT In Vitro
"recombinant interferon alpha treatment of erythroid progenitors derived from cord blood results in increased apoptosis"
Supports interferon acting directly on human erythroid progenitors. Indirect because it is a cord-blood culture result applied to the neonatal anemia of patients.
Endosomal TLR-Dependent Anti-Nucleic Acid Autoantibody Production
Accumulated self DNA also breaks B-cell tolerance. Patients develop fluctuating anti-DNA antibodies, and some develop a lupus-like picture with antinuclear antibodies and hypocomplementemia. In the DNase II-deficient mouse this autoantibody arm depends on the endosomal TLR chaperone Unc93b1 rather than on STING, so it is modeled as a separate route from the self DNA rather than as a consequence of the interferon node.
toll-like receptor 9 signaling pathway GO:0034162 ↑ INCREASED Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased toll-like receptor 9 signaling pathway (GO:0034162). GO:0034162 is a biological process from the Gene Ontology.
Downstream
Anti-dsDNA antibody positivity
Show evidence (2 references)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Serial testing also revealed fluctuating significant titers of anti-DNA antibodies in all three affected individuals."
The anti-DNA autoantibodies seen in all three index patients.
PMID:25548216 SUPPORT INDIRECT PRIMARY RESULT Model Organism
"whereas DNase II(-/-) Ifnar(-/-) mice also deficient in Unc93b, a chaperone required for TLR7/9 endosomal localization, fail to produce autoantibodies to nucleic acids"
Endosomal TLR signaling, not STING, drives the anti-nucleic acid autoantibodies in the DNase II mouse. Indirect because it is a mouse genetic dissection applied to the human autoantibody finding.
AIM2 Inflammasome Activation in Inflamed Joints
A second cytosolic DNA sensor, the AIM2 inflammasome, contributes to the joint disease. In the DNase II-deficient mouse, loss of AIM2 reduces joint inflammation and caspase-1 activation while leaving the systemic inflammation AIM2-independent, so AIM2 is modeled as a tissue-specific contributor to the arthropathy rather than a driver of the whole syndrome. Its role in human DNASE2 deficiency is inferred from the mouse.
AIM2 inflammasome complex assembly GO:0140970 ↑ INCREASED Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased AIM2 inflammasome complex assembly (GO:0140970). GO:0140970 is a biological process from the Gene Ontology.
Downstream
Deforming Arthropathy
Show evidence (1 reference)
PMID:26114879 SUPPORT INDIRECT PRIMARY RESULT Model Organism
"Arthritis-prone mice lacking AIM2 displayed strongly decreased signs of joint inflammation and associated histopathological findings."
AIM2 deletion reduces the joint disease in the self-DNA arthritis model. Indirect because the sensor's role in human DNASE2 deficiency is inferred from the mouse.
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Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for DNASE2 Deficiency Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
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Phenotypes

25
Blood 5
Neonatal Anemia VERY_FREQUENT HP:0001903 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Anemia (HP:0001903). HP:0001903 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"All three children demonstrated severe non-regenerative anemia and thrombocytopenia at birth necessitating red blood cell and platelet transfusions"
Severe neonatal anemia in all three index patients.
Thrombocytopenia VERY_FREQUENT HP:0001873 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Thrombocytopenia (HP:0001873). HP:0001873 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"All three children demonstrated severe non-regenerative anemia and thrombocytopenia at birth necessitating red blood cell and platelet transfusions"
Neonatal thrombocytopenia in all three index patients.
Pancytopenia HP:0001876 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Pancytopenia (HP:0001876). HP:0001876 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Neonatal HSM, cholestatic hepatitis and pancytopenia requiring multiple RBC and platelet transfusions"
Neonatal pancytopenia at presentation in the index patients.
PMID:42491852 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"severe pancytopenia, with haemoglobin of 8.2 g/dL, platelet count of 12×10⁹/L, white blood cell count of 1.3×10⁹/L, and an absolute neutrophil count of 0"
Severe persistent pancytopenia in the antenatal-onset case.
Circulating nucleated red blood cells HP:0033281 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Circulating nucleated red blood cells (HP:0033281). HP:0033281 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Fresh blood samples from F1:V-1 and F1:V-3 demonstrated a marked increase in the percentage of circulating erythroblasts, whilst the number of reticulocytes was the same as in controls"
Circulating erythroblasts in the index patients.
Hypogammaglobulinemia Decreased circulating immunoglobulin concentration HP:0004313 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Decreased circulating immunoglobulin concentration (HP:0004313). HP:0004313 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"frank hypogammaglobulinemia from 7 years of age requiring IVIG; progressive CD4+ and CD8+ lymphopenia first recorded at age 6 years"
Hypogammaglobulinemia and lymphopenia in an index patient.
Cardiovascular 2
Hepatosplenomegaly VERY_FREQUENT HP:0001433 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hepatosplenomegaly (HP:0001433). HP:0001433 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"together with hepatosplenomegaly and cholestatic hepatitis which resolved in the first few weeks of life"
Neonatal hepatosplenomegaly with cholestatic hepatitis in the index patients.
Vasculitis in the skin HP:0200029 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Vasculitis in the skin (HP:0200029). HP:0200029 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"At the age of 13 years, this patient also developed vasculitic skin lesions"
Vasculitic skin lesions in an index patient.
Digestive 2
Cholestasis HP:0001396 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Cholestasis (HP:0001396). HP:0001396 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:42491852 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"conjugated hyperbilirubinemia (total bilirubin 300 µmol/L, conjugated fraction 255 µmol/L), consistent with cholestatic liver disease"
Cholestatic liver disease with conjugated hyperbilirubinemia in the antenatal-onset case.
Hepatic Fibrosis HP:0001395 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hepatic fibrosis (HP:0001395). HP:0001395 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Both these children also subsequently developed hepatosplenomegaly with fibrosis identified on liver biopsy"
Liver fibrosis on biopsy in two index patients.
Endocrine 2
Reduced Growth Hormone Response Decreased response to growth hormone stimulation test HP:0000824 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Reduced growth hormone response to arginine stimulation, annotated with Decreased response to growth hormone stimulation test (HP:0000824). HP:0000824 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Reduced response to arginine suggestive of growth hormone deficiency noted at age 17 years"
Reduced growth hormone stimulation response in an index patient.
Type I diabetes mellitus HP:0100651 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Type I diabetes mellitus (HP:0100651). HP:0100651 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"F1:V-3 developed antibody-negative insulin-dependent diabetes mellitus at 5 years of age"
Insulin-dependent diabetes in one index patient.
Genitourinary 2
Membranoproliferative Glomerulonephritis HP:0000793 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Membranoproliferative glomerulonephritis (HP:0000793). HP:0000793 is a phenotype from the Human Phenotype Ontology.
Sequelae: Proteinuria
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"with membranoproliferative glomerulonephritis documented in the younger affected child from Family 1 (F1; F1:V-3) and the proband from Family 2 (F2; F2:II-4)"
Membranoproliferative glomerulonephritis in two index patients.
Proteinuria HP:0000093 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Proteinuria (HP:0000093). HP:0000093 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"the onset of proteinuria between the ages of 6 and 10 years"
Proteinuria in all three index patients.
Immune 3
Chilblains HP:0009710 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Chilblain-like lesions, annotated with Chilblains (HP:0009710). HP:0009710 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Lipodystrophy of the limbs and chilblain-like lesions of the hands and feet since the age of 13 years"
Chilblain-like lesions of the hands and feet in an index patient.
Anti-dsDNA antibody positivity VERY_FREQUENT HP:0020151 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Anti-dsDNA antibody positivity (HP:0020151). HP:0020151 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Serial testing also revealed fluctuating significant titers of anti-DNA antibodies in all three affected individuals."
Anti-DNA antibodies in all three index patients.
Type I Interferon Signature Increased circulating Interferon-alpha concentration HP:0034513 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Increased circulating Interferon-alpha concentration (HP:0034513). HP:0034513 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"we recorded increased levels of interferon alpha protein in serum and plasma from all three patients, comparable to levels observed in other type I interferonopathies"
Raised interferon alpha protein in all index patients.
Metabolism 3
Recurrent Fever HP:0001954 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Recurrent fever (HP:0001954). HP:0001954 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"All three patients also experienced recurrent fevers starting between 5 and 7 years of age"
Recurrent fevers in the index patients.
Elevated erythrocyte sedimentation rate HP:0003565 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Elevated erythrocyte sedimentation rate (HP:0003565). HP:0003565 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"All three patients demonstrated a persistent increase in erythrocyte sedimentation rate (ESR)"
Persistently raised ESR in the index patients.
Hydrops fetalis HP:0001789 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hydrops fetalis (HP:0001789). HP:0001789 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"F1:V-2 denotes a fetus delivered in late pregnancy with hydrops fetalis, hepatosplenomegaly and petechiae."
Hydrops fetalis in a fetus of an index family.
Musculoskeletal 3
Deforming Arthropathy Arthritis HP:0001369 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Arthritis (HP:0001369). HP:0001369 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Starting at 8 years of age, F2:II-4 experienced the onset of a non-destructive, deforming arthropathy which has been refractory to broad-spectrum immunosuppression, anti-IL-1 receptor, anti-IL-1β and anti-TNFα therapies"
The deforming arthropathy in the index patient.
Joint contracture HP:0034392 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Joint contracture (HP:0034392). HP:0034392 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:41472683 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"both patients presented with progressive joint contractures and features suggestive of osteopenia"
Joint contractures and osteopenia in the two splice-variant patients.
Lipodystrophy HP:0009125 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Lipodystrophy (HP:0009125). HP:0009125 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Lipodystrophy of the limbs and chilblain-like lesions of the hands and feet since the age of 13 years"
Lipodystrophy in an index patient.
Nervous System 2
Subcortical White Matter Lesions Hyperintensity of cerebral white matter on MRI HP:0030890 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Subcortical white matter hyperintensities on MRI, annotated with Hyperintensity of cerebral white matter on MRI (HP:0030890). HP:0030890 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"F1:V-3 and F2:II-4 were recorded to show non-specific sub-cortical white matter lesions on cerebral imaging in the absence of overt neurological signs"
Subcortical white matter lesions in two of three index patients.
Learning Difficulties Specific learning disability HP:0001328 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Learning difficulties, annotated with Specific learning disability (HP:0001328). HP:0001328 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"although F1:V-3 exhibited learning difficulties necessitating extra help at school"
Learning difficulties in an index patient; the clinical table records mild learning difficulties in the second.
Growth 1
Failure to Thrive HP:0001508 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Failure to thrive (HP:0001508). HP:0001508 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Continued joint disease with Cushingoid features and failure to thrive, without signs of puberty"
Failure to thrive in the index patient with the deforming arthropathy.
PMID:41472683 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"They presented at birth with rash, thrombocytopenia, and anemia, later developing neutropenia, arthritis, failure to thrive, and systemic inflammation."
Failure to thrive in both splice-variant patients.
🧬

Genetic Associations

1
DNASE2
Gene: DNASE2 hgnc:2960 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is DNASE2 (hgnc:2960). hgnc:2960 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: CAUSATIVE variant_origin: GERMLINE
Show evidence (3 references)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"In both families we identify biallelic mutations in DNASE2, associated with a loss of DNase II endonuclease activity."
The index report establishing biallelic DNASE2 loss of function as the cause.
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT In Vitro
"lysates of fibroblasts from F1:V-1 and F2:II-4 demonstrated a marked reduction of DNase II activity against the same substrate; DNase II activity in these cells could be restored by expression of constructs coding for wild-type protein"
Reduced enzyme activity in patient cells, rescued by wild-type DNASE2, supports causality.
PMID:41472683 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Both patients carried a homozygous DNASE2 splice site variant (c.511+5G>A), resulting in exon 4 skipping and impaired DNase II activity."
An independent recurrent allele in two further unrelated patients. This source is a Research Square preprint indexed in PubMed; no peer-reviewed version was found.
💊

Medical Actions

3
JAK Inhibition (Ruxolitinib)
Action: targeted therapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is targeted therapy (NCIT:C93352). NCIT:C93352 is a clinical intervention from the NCI Thesaurus. Ontology label: Targeted Therapy NCIT:C93352
Agent: ruxolitinib CHEBI:66919 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses ruxolitinib (CHEBI:66919). CHEBI:66919 is a therapeutic agent from Chemical Entities of Biological Interest.
Platform: Small molecule
JAK1/2 inhibition with ruxolitinib blocks the JAK-STAT signaling driven by type I interferon. It has been followed by clinical and laboratory improvement, including recovery of cytopenias, resolution of cholestasis and reduction of inflammation, in reported patients, including a preterm neonate. In the index study, ruxolitinib reduced STAT1 and STAT3 phosphorylation in patient cells in vitro.
Mechanism Target:
Type I Interferon Overproduction and JAK-STAT Signaling — Blocks JAK1/2 downstream of the type I interferon receptor, interrupting the interferon-driven signaling.
Show evidence (2 references)
PMID:42491852 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"treatment with ruxolitinib in our patient resulted in marked clinical and laboratory improvement, supporting its role as a potentially disease-modifying therapy in Dnase2 deficiency"
Clinical and laboratory improvement on ruxolitinib in the antenatal-onset case.
PMID:29259162 SUPPORT INDIRECT PRIMARY RESULT In Vitro
"Increased phosphorylation of STAT1 and STAT3 observed in cultured lymphocytic-enriched fractions from F1:V-1 compared to a healthy control (HC), treated or not with the JAK1/2 inhibitor ruxolitinib."
Ruxolitinib reduced STAT1/STAT3 phosphorylation in patient cells in vitro, the mechanistic rationale for JAK inhibition. Indirect because it is an ex vivo cellular readout rather than a clinical outcome.
Supportive Transfusion
Action: red blood cell and platelet transfusionNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is red blood cell and platelet transfusion, annotated with Blood Transfusion (NCIT:C15192). NCIT:C15192 is a clinical intervention from the NCI Thesaurus. Ontology label: Blood Transfusion NCIT:C15192
Platform: Other
Red blood cell and platelet transfusions for the neonatal cytopenias.
Mechanism Target:
Neonatal Anemia — Red cell transfusion corrects the transfusion-dependent neonatal anemia.
Thrombocytopenia — Platelet transfusion supports the neonatal thrombocytopenia.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"necessitating red blood cell and platelet transfusions"
Transfusion support for the neonatal cytopenias.
Immunoglobulin Replacement Therapy
Action: Intravenous Immunoglobulin TherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Intravenous Immunoglobulin Therapy (NCIT:C121331). NCIT:C121331 is a clinical intervention from the NCI Thesaurus. NCIT:C121331
Platform: Protein replacement
Intravenous immunoglobulin for the hypogammaglobulinemia seen in one index patient.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"frank hypogammaglobulinemia from 7 years of age requiring IVIG"
Immunoglobulin replacement for the hypogammaglobulinemia in an index patient.
🔬

Biochemical Markers

2
Interferon-stimulated gene score (Elevated)
Context: An elevated interferon-stimulated gene score in whole blood is the shared laboratory signature of the type I interferonopathies and was used to ascertain the index patients, who overexpressed a six-ISG panel (IFI27, IFI44L, IFIT1, ISG15, RSAD2, SIGLEC1).
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"demonstrating increased expression of a panel of six interferon-stimulated genes (ISGs) (IFI27, IFI44L, IFIT1, ISG15, RSAD2, and SIGLEC1)"
The ISG panel used to detect the interferon signature in the index patients.
Hyperferritinemia (Elevated)
Context: Markedly raised ferritin with hypofibrinogenemia and cytopenias produced an HLH-like picture in the antenatal-onset case, although full HLH 2004 criteria were not met.
Show evidence (1 reference)
PMID:42491852 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"ferritin levels were markedly elevated (6886 ug/L)"
Marked hyperferritinemia in the HLH-like antenatal-onset presentation.
🔬

Diagnosis

2
Exome sequencing for biallelic DNASE2 variants
The diagnosis rests on finding biallelic DNASE2 variants by exome sequencing, with functional confirmation of reduced DNase II activity in patient cells.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"We performed whole-exome sequencing using DNA from the three patients and their parents"
Exome sequencing identified the biallelic DNASE2 genotypes.
Type I interferon signature testing
An interferon-stimulated gene score or interferon alpha measurement supports the diagnosis and tracks disease activity, as for other type I interferonopathies.
Show evidence (1 reference)
PMID:29259162 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"By systematic screening using a panel of interferon-stimulated genes we identify two siblings and a singleton"
ISG screening is how the index patients were ascertained.
📊

Prevalence

1
Worldwide
Cases In Literature Ultra Rare
An ultra-rare disorder. The 2017 index report described three patients from two families; a 2025 preprint called the total six patients before adding two more, and further single cases have since been reported, so fewer than fifteen patients are published. No population estimate exists, so rate_per_100000 is left unset.
Show evidence (1 reference)
PMID:41472683 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"To date, only 6 patients have been reported, with clinical manifestations predominantly including congenital anemia, hepatosplenomegaly, and systemic inflammation"
The reported patient total before the two cases this preprint adds.
🐁

Animal Models

2
Dnase2 knockout mouse
Constitutive DNase II-null mice die in late embryogenesis or at birth from a severe anemia, because macrophages at the site of fetal liver definitive erythropoiesis cannot digest the nuclei expelled by erythroid precursors. The model reproduces the macrophage DNA accumulation and the lethal fetal anemia but not the full postnatal human syndrome, which is only seen once the embryonic lethality is bypassed.
Species
Mus musculus
Genotype
Dnase2-/- (constitutive null)
Publication
PMID:11375492
Pathograph links
Interferon-Driven Suppression of Fetal and Neonatal Erythropoiesis recapitulates fidelity: moderate observes: organism Reproduces the type I interferon-dependent failure of definitive erythropoiesis.
Limitations: The mouse null is embryonic-lethal, so it models the fetal anemia rather than the resolving neonatal anemia and later multisystem disease of the hypomorphic human alleles.
Show evidence (1 reference)
PMID:15568025 SUPPORT DIRECT PRIMARY RESULT Model Organism
"the inability to degrade DNA derived from erythroid precursors results in interferon-beta production that induces expression of a specific set of interferon-responsive genes associated with embryonic lethality in DNase II-deficient mice"
The interferon-driven lethal anemia this node represents.
Dnase2 Ifnar1 double-knockout mouse
Removing the type I interferon receptor rescues the embryonic lethality, and the surviving mice develop a chronic TNF-dependent polyarthritis resembling rheumatoid arthritis, with cytopenia, extramedullary hematopoiesis and liver fibrosis. This model captures the postnatal interferon-independent inflammatory arm, including the arthropathy.
Species
Mus musculus
Genotype
Dnase2-/- Ifnar1-/- (type I interferon receptor double knockout)
Publication
PMID:17066036
Pathograph links
STING-TBK1-Driven Proinflammatory Cytokine Production recapitulates fidelity: moderate observes: organism Reproduces the TNF-driven inflammatory arthritis of the interferon-independent arm.
Limitations: The arthritis arm is studied with the interferon receptor deleted, so it models the interferon-independent cytokine route in isolation rather than the combined human disease in which interferon signaling is intact.
Show evidence (1 reference)
PMID:17066036 SUPPORT DIRECT PRIMARY RESULT Model Organism
"DNase II-/-IFN-IR-/- mice and mice with an induced deletion of the DNase II gene develop a chronic polyarthritis resembling human rheumatoid arthritis"
The TNF-dependent polyarthritis this model contributes.
{ }

Source YAML

click to show 
name: DNASE2 Deficiency
creation_date: '2026-10-14T12:36:44Z'
category: Mendelian
description: >-
  DNASE2 deficiency is an autosomal recessive type I interferonopathy caused by
  biallelic loss-of-function variants in DNASE2, which encodes deoxyribonuclease
  II, the acid endonuclease that digests DNA inside lysosomes. Macrophages rely on
  it to degrade the nuclei expelled by maturing erythroblasts and the chromatin of
  engulfed apoptotic cells. When it fails, undigested self DNA engages the
  cGAS-STING DNA-sensing pathway, and the result is constitutive type I interferon
  production with a high interferon-stimulated gene signature, plus an
  interferon-independent proinflammatory cytokine arm.

  The presentation is neonatal: severe non-regenerative anemia and thrombocytopenia
  needing transfusion, hepatosplenomegaly and cholestatic hepatitis, sometimes
  beginning before birth with fetal anemia and hydrops. In the published patients
  the neonatal cytopenias resolved over weeks to months and were followed in
  childhood by recurrent fevers, membranoproliferative glomerulonephritis with
  proteinuria, hepatic fibrosis, a deforming arthropathy with contractures,
  vasculitic and nodular skin lesions, chilblain-like lesions, lipodystrophy,
  anti-DNA autoantibodies and failure to thrive. Two of the three index patients
  had subcortical white matter lesions on MRI with learning difficulties. Fewer
  than fifteen patients are reported. JAK1/2 inhibition has
  been followed by clinical improvement in several of them.
synonyms:
- DNase II deficiency
- Autoinflammatory-pancytopenia syndrome
- Autoinflammatory-pancytopenia syndrome due to DNASE2 deficiency
- Type I interferonopathy due to DNase II deficiency
disease_term:
  preferred_term: autoinflammatory-pancytopenia syndrome due to DNASE2 deficiency
  term:
    id: MONDO:0800132
    label: autoinflammatory-pancytopenia syndrome due to DNASE2 deficiency
parents:
- Type I Interferonopathy
- Autoinflammatory Disorder
- Inborn Errors of Immunity
classifications:
  harrisons_chapter:
  - classification_value: IMMUNE_RHEUMATOLOGIC
    notes: >-
      A monogenic autoinflammatory inborn error of immunity, managed by
      immunology and rheumatology.
  - classification_value: GENETICS_ENVIRONMENT_DISEASE
    notes: Autosomal recessive single-gene disorder.
  iuis_category:
    classification_value: autoinflammatory syndrome
    notes: >-
      IUIS 2024 phenotypic classification, Table 7 (autoinflammatory disorders),
      section 1 (type 1 interferonopathies), row "DNase II deficiency". The 2022
      update (PMID:35748970) carries the same row under the older OMIM gene
      number 126350; the 2024 row gives the phenotype number 619858.
    evidence:
    - reference: PMID:41608114
      reference_title: "Human inborn errors of immunity: 2024 update on the classification from the International Union of Immunological Societies Expert Committee."
      supports: SUPPORT
      evidence_source: OTHER
      quote_role: REVIEW_SYNTHESIS
      snippet: "DNase II deficiency | DNASE2 | AR | 619858 | Not assessed | Not assessed | DNase II degrades and eliminates DNA. Loss of DNase II activity induces type I interferon signaling"
      explanation: >-
        The IUIS 2024 Table 7 interferonopathy row for DNase II deficiency, with
        the DNASE2 gene, autosomal recessive inheritance and OMIM 619858.
references:
- reference: PMID:29259162
  title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
inheritance:
- name: Autosomal recessive inheritance
  description: >-
    Affected individuals are homozygous or compound heterozygous for DNASE2
    loss-of-function alleles, and parents tested in the index families were
    heterozygous carriers.
  inheritance_term:
    preferred_term: Autosomal recessive inheritance
    term:
      id: HP:0000007
      label: Autosomal recessive inheritance
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "Both sets of parents were heterozygous for the relevant familial variant, and all four unaffected siblings from both families were either homozygous or heterozygous wild type"
    explanation: Segregation in the two index families fits autosomal recessive inheritance.
  - reference: PMID:42491852
    reference_title: "Severe Antenatal Presentation of a Novel Dnase2 Mutation in a Preterm Omani Neonate: Expanding the Clinical Spectrum of an Ultra-Rare Interferonopathy."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "Whole-exome sequencing identified two novel heterozygous variants in the Dnase2 gene (p.Gly48AlafsTer49 and p.Met1), consistent with a compound heterozygous state"
    explanation: A compound heterozygous genotype in a child of non-consanguineous parents, also consistent with recessive inheritance.
genetic:
- name: DNASE2
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  gene_term:
    preferred_term: DNASE2
    term:
      id: hgnc:2960
      label: DNASE2
  notes: >-
    Reported pathogenic alleles include the homozygous missense variants
    c.347G>C (p.Gly116Ala, which also causes exon 4 skipping) and c.362A>T
    (p.Asp121Val) in the index families, the homozygous proximal intronic splice
    variant c.511+5G>A (exon 4 skipping) in two unrelated Tatar and Bashkir
    patients, and a compound heterozygous frameshift (p.Gly48AlafsTer49) plus
    start-loss (p.Met1?) genotype in an antenatal-onset case. The authors of that
    case suggest that null alleles on both sides explain its severity, whereas
    the earlier alleles are hypomorphic with leaky splicing or residual activity.
    A single heterozygous DNASE2 p.Gly322Asp variant was reported in a Spanish
    patient with a suspected lupus-like disorder (PMID:32222431); one heterozygous
    allele does not fit the recessive model, so that case is not counted here. No
    ClinGen gene-disease validity classification was found for DNASE2, so
    gene_disease_validity is left unset.
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "In both families we identify biallelic mutations in DNASE2, associated with a loss of DNase II endonuclease activity."
    explanation: The index report establishing biallelic DNASE2 loss of function as the cause.
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: IN_VITRO
    quote_role: PRIMARY_RESULT
    snippet: "lysates of fibroblasts from F1:V-1 and F2:II-4 demonstrated a marked reduction of DNase II activity against the same substrate; DNase II activity in these cells could be restored by expression of constructs coding for wild-type protein"
    explanation: Reduced enzyme activity in patient cells, rescued by wild-type DNASE2, supports causality.
  - reference: PMID:41472683
    reference_title: "Type I interferon-mediated autoinflammation in two unrelated patients due to a proximal intronic splice site variant in DNASE2."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "Both patients carried a homozygous DNASE2 splice site variant (c.511+5G>A), resulting in exon 4 skipping and impaired DNase II activity."
    explanation: >-
      An independent recurrent allele in two further unrelated patients. This
      source is a Research Square preprint indexed in PubMed; no peer-reviewed
      version was found.
pathophysiology:
- name: Biallelic DNASE2 Loss of Function
  conforms_to: "lysosomal_substrate_accumulation#Lysosomal Hydrolase or Cofactor Deficiency"
  description: >-
    Biallelic DNASE2 variants abolish or sharply reduce the activity of DNase II,
    a lysosomal acid endonuclease. In the index families the missense and
    exon 4-skipping alleles left little or no measurable activity against plasmid
    DNA when expressed in HEK293T cells, and patient fibroblast lysates had
    markedly reduced activity that wild-type DNASE2 restored. This is the
    lysosomal-hydrolase substitution at the trigger node of the lysosomal
    substrate accumulation module; the stored substrate is DNA.
  role: trigger
  biological_scale: MOLECULAR
  genes:
  - preferred_term: DNASE2
    term:
      id: hgnc:2960
      label: DNASE2
  molecular_functions:
  - preferred_term: deoxyribonuclease II activity
    term:
      id: GO:0004531
      label: deoxyribonuclease II activity
    modifier: DECREASED
  genetic_context:
    variant_origin: GERMLINE
    functional_impact_category: LOSS_OF_FUNCTION
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: IN_VITRO
    quote_role: PRIMARY_RESULT
    snippet: "Expression in HEK293T cells of mutant constructs lacking exon 4, or with the c.347G>C (Gly116Ala) or the c.362A>T (Asp121Val) substitutions, was associated with reduced levels of DNase II activity against circularized plasmid DNA compared to controls"
    explanation: Recombinant expression of the patient alleles shows the loss of nuclease activity.
  downstream:
  - target: Undegraded DNA Accumulation in Macrophage Lysosomes
    causal_link_type: DIRECT
    description: >-
      Without DNase II, macrophages that engulf erythroblast nuclei and apoptotic
      cells cannot digest their DNA.
    evidence:
    - reference: PMID:11375492
      reference_title: "Requirement of DNase II for definitive erythropoiesis in the mouse fetal liver."
      supports: SUPPORT
      directness: DIRECT
      evidence_source: MODEL_ORGANISM
      quote_role: PRIMARY_RESULT
      snippet: "DNase II in macrophages appears to be responsible for destroying the nuclear DNA expelled from erythroid precursor cells."
      explanation: Places DNase II in the macrophage step that degrades expelled erythroid nuclei.
- name: Undegraded DNA Accumulation in Macrophage Lysosomes
  conforms_to: "lysosomal_substrate_accumulation#Lysosomal Substrate Accumulation"
  description: >-
    Macrophages at sites of definitive erythropoiesis (fetal liver Kupffer cells,
    bone marrow macrophages) and at sites of developmental apoptosis engulf
    expelled erythroid nuclei and apoptotic cells but cannot digest their
    chromatin, which accumulates as undigested DNA in their lysosomes. Unlike the
    classical lysosomal storage diseases, the damage that follows is driven by
    innate immune sensing of the stored DNA rather than by storage cytotoxicity,
    so this entry conforms only to the first two nodes of the lysosomal module.
  role: central_effector
  biological_scale: CELLULAR
  cell_types:
  - preferred_term: macrophage
    term:
      id: CL:0000235
      label: macrophage
  - preferred_term: Kupffer cell
    term:
      id: CL:0000091
      label: Kupffer cell
  biological_processes:
  - preferred_term: DNA catabolic process
    term:
      id: GO:0006308
      label: DNA catabolic process
    modifier: DECREASED
  evidence:
  - reference: PMID:15568025
    reference_title: "Lethal anemia caused by interferon-beta produced in mouse embryos carrying undigested DNA."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: MODEL_ORGANISM
    quote_role: PRIMARY_RESULT
    snippet: "The livers of DNase II-deficient mouse embryos contain many macrophages carrying undigested DNA, and the embryos die in utero."
    explanation: Direct observation of DNA-laden macrophages in DNase II-null fetal liver.
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: MODEL_ORGANISM
    quote_role: BACKGROUND
    snippet: "DNase II null mice accumulate DNA in the lysosomes of fetal liver Kupffer cells and bone marrow macrophages"
    explanation: >-
      Summarizes the mouse work on the lysosomal location of the stored DNA in
      Kupffer cells and bone marrow macrophages. The quote is the human paper's
      restatement of earlier mouse studies, hence BACKGROUND.
  downstream:
  - target: cGAS-STING Activation by Undegraded Self DNA
    causal_link_type: DIRECT
  - target: Endosomal TLR-Dependent Anti-Nucleic Acid Autoantibody Production
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: AIM2 Inflammasome Activation in Inflamed Joints
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
- name: cGAS-STING Activation by Undegraded Self DNA
  conforms_to: "cgas_sting_pathway_activation#Cytosolic DNA Accumulation and cGAS-Dependent cGAMP Synthesis"
  description: >-
    DNA that escapes lysosomal degradation is detected by cGAS, which synthesizes
    cGAMP and activates STING. This is the DNASE2-specific substitution at the
    module's entry node: the DNA reaches cGAS from a failed lysosomal digestion
    rather than from loss of a cytosolic nuclease such as TREX1. The route by
    which lysosomal DNA reaches cytosolic cGAS is not established in the cited
    sources. The pathway dependence is shown genetically in mice: cGAMP
    accumulates in DNase II-deficient tissues in a cGAS-dependent way, and
    deleting cGas or Sting rescues both the embryonic lethality and the
    arthritis.
  role: central_effector
  biological_scale: MOLECULAR
  cell_types:
  - preferred_term: macrophage
    term:
      id: CL:0000235
      label: macrophage
  molecular_functions:
  - preferred_term: 2',3'-cyclic GMP-AMP synthase activity
    term:
      id: GO:0061501
      label: 2',3'-cyclic GMP-AMP synthase activity
    modifier: INCREASED
  biological_processes:
  - preferred_term: cGAS/STING signaling pathway
    term:
      id: GO:0140896
      label: cGAS/STING signaling pathway
    modifier: INCREASED
  evidence:
  - reference: PMID:26371324
    reference_title: "Activation of cyclic GMP-AMP synthase by self-DNA causes autoimmune diseases."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: MODEL_ORGANISM
    quote_role: PRIMARY_RESULT
    snippet: "Similarly, deletion of cGas in mice lacking DNaseII, a lysosomal enzyme that digests DNA, rescued the lethal autoimmune phenotypes of the DNaseII(-/-) mice."
    explanation: Genetic rescue places cGAS downstream of DNase II loss.
  - reference: PMID:26371324
    reference_title: "Activation of cyclic GMP-AMP synthase by self-DNA causes autoimmune diseases."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: MODEL_ORGANISM
    quote_role: PRIMARY_RESULT
    snippet: "we found that cGAMP accumulated in mouse tissues deficient in Trex1 or DNaseII and that this accumulation was dependent on cGAS"
    explanation: cGAMP, the product of activated cGAS, is raised in DNase II-deficient tissue.
  - reference: PMID:23132945
    reference_title: "STING manifests self DNA-dependent inflammatory disease."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: MODEL_ORGANISM
    quote_role: PRIMARY_RESULT
    snippet: "DNase II-dependent embryonic lethality was rescued by loss of STING function, and polyarthritis completely prevented"
    explanation: STING deletion rescues both the embryonic and the postnatal DNase II phenotypes.
  downstream:
  - target: Type I Interferon Overproduction and JAK-STAT Signaling
    causal_link_type: DIRECT
  - target: STING-TBK1-Driven Proinflammatory Cytokine Production
    causal_link_type: DIRECT
- name: Type I Interferon Overproduction and JAK-STAT Signaling
  conforms_to: "cgas_sting_pathway_activation#TBK1-IRF3 Activation and Type I Interferon Induction"
  description: >-
    Activated STING recruits TBK1 and drives IRF3-dependent transcription of type
    I interferons. In patients this shows as raised interferon alpha protein, a
    whole-blood interferon-stimulated gene signature like that of other type I
    interferonopathies, and constitutive STAT1 and STAT3 phosphorylation in
    unstimulated T cells and monocytes. The signaling is JAK-STAT dependent, which
    is the rationale for JAK inhibition.
  role: central_effector
  biological_scale: MOLECULAR
  cell_types:
  - preferred_term: monocyte
    term:
      id: CL:0000576
      label: monocyte
  biological_processes:
  - preferred_term: positive regulation of type I interferon production
    term:
      id: GO:0032481
      label: positive regulation of type I interferon production
    modifier: INCREASED
  - preferred_term: JAK-STAT signaling
    term:
      id: GO:0007259
      label: cell surface receptor signaling pathway via JAK-STAT
    modifier: INCREASED
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "We record increased interferon alpha protein levels using digital ELISA, enhanced interferon signaling by RNA-Seq analysis and constitutive upregulation of phosphorylated STAT1 and STAT3 in patient lymphocytes and monocytes."
    explanation: Direct patient evidence for interferon overproduction and constitutive JAK-STAT signaling.
  downstream:
  - target: Type I Interferon Signature
    causal_link_type: DIRECT
  - target: Interferon-Driven Suppression of Fetal and Neonatal Erythropoiesis
    causal_link_type: DIRECT
  - target: Membranoproliferative Glomerulonephritis
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Hepatic Fibrosis
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Vasculitis in the skin
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
- name: STING-TBK1-Driven Proinflammatory Cytokine Production
  description: >-
    STING signaling also drives an interferon-independent proinflammatory cytokine
    arm. In patients the serum cytokine pattern overlaps that of STING
    gain-of-function disease, with raised TNF-alpha and variable IL-1beta and
    IL-6. Mouse work shows this arm runs through TBK1 recruitment to STING and
    NF-kB rather than through IRF3 and type I interferon: a STING mutant that
    cannot induce interferon still causes TNF- and IL-6-dependent polyarthritis.
    This arm is the likely driver of the deforming arthropathy.
  role: central_effector
  biological_scale: CELLULAR
  biological_processes:
  - preferred_term: tumor necrosis factor production
    term:
      id: GO:0032640
      label: tumor necrosis factor production
    modifier: INCREASED
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "suggesting consistently elevated protein levels of TNFα in both patients, a more variable elevation of IL-1β, and concentrations of IL-6 mostly reflecting normal physiological levels"
    explanation: The non-interferon cytokine pattern measured in patient serum.
  - reference: PMID:34901991
    reference_title: "TBK1 recruitment to STING mediates autoinflammatory arthritis caused by defective DNA clearance."
    supports: SUPPORT
    directness: INDIRECT
    evidence_source: MODEL_ORGANISM
    quote_role: PRIMARY_RESULT
    snippet: "DNase II-/-STING-S365A mice exhibited severe polyarthritis, which was alleviated by neutralizing antibodies against TNF-α or IL-6 receptor"
    explanation: >-
      A STING mutant unable to induce type I interferon still produces
      TNF- and IL-6-dependent arthritis, placing the arthritis on the
      interferon-independent STING-TBK1 arm. Indirect because it is a mouse
      genetic dissection rather than a human observation.
  downstream:
  - target: Deforming Arthropathy
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Recurrent Fever
    causal_link_type: DIRECT
- name: Interferon-Driven Suppression of Fetal and Neonatal Erythropoiesis
  description: >-
    Type I interferon produced by DNA-laden macrophages acts on erythropoiesis.
    In DNase II-null mice interferon-beta from resident fetal liver macrophages
    causes a lethal anemia that is rescued by deleting the type I interferon
    receptor. In patients the neonatal anemia is non-regenerative with increased
    circulating erythroblasts and reticulocyte counts inappropriate for the
    hemoglobin, a picture of ineffective erythropoiesis, and recombinant
    interferon alpha increased apoptosis of cord-blood erythroid progenitors.
  role: consequence
  biological_scale: ORGANISM
  cell_types:
  - preferred_term: erythroblast
    term:
      id: CL:0000765
      label: erythroblast
  biological_processes:
  - preferred_term: definitive erythrocyte differentiation
    term:
      id: GO:0060318
      label: definitive erythrocyte differentiation
    modifier: DECREASED
  evidence:
  - reference: PMID:15568025
    reference_title: "Lethal anemia caused by interferon-beta produced in mouse embryos carrying undigested DNA."
    supports: SUPPORT
    directness: INDIRECT
    evidence_source: MODEL_ORGANISM
    quote_role: PRIMARY_RESULT
    snippet: "When the DNase II-deficient mice were crossed with mice deficient in type I interferon receptor, the resultant 'double-mutant' mice were born healthy."
    explanation: >-
      Deleting the interferon receptor rescues the lethal anemia, placing type I
      interferon causally upstream of the erythropoietic failure. Indirect because
      it is a mouse genetic result applied to the human neonatal anemia.
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "Fresh blood samples from F1:V-1 and F1:V-3 demonstrated a marked increase in the percentage of circulating erythroblasts, whilst the number of reticulocytes was the same as in controls"
    explanation: The circulating erythroblast increase with inappropriate reticulocytes in patients, indicating ineffective erythropoiesis.
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: INDIRECT
    evidence_source: IN_VITRO
    quote_role: PRIMARY_RESULT
    snippet: "recombinant interferon alpha treatment of erythroid progenitors derived from cord blood results in increased apoptosis"
    explanation: >-
      Supports interferon acting directly on human erythroid progenitors.
      Indirect because it is a cord-blood culture result applied to the
      neonatal anemia of patients.
  downstream:
  - target: Neonatal Anemia
    causal_link_type: DIRECT
  - target: Thrombocytopenia
    causal_link_type: DIRECT
  - target: Circulating nucleated red blood cells
    causal_link_type: DIRECT
- name: Endosomal TLR-Dependent Anti-Nucleic Acid Autoantibody Production
  description: >-
    Accumulated self DNA also breaks B-cell tolerance. Patients develop
    fluctuating anti-DNA antibodies, and some develop a lupus-like picture with
    antinuclear antibodies and hypocomplementemia. In the DNase II-deficient mouse
    this autoantibody arm depends on the endosomal TLR chaperone Unc93b1 rather
    than on STING, so it is modeled as a separate route from the self DNA rather
    than as a consequence of the interferon node.
  role: consequence
  biological_scale: ORGANISM
  biological_processes:
  - preferred_term: toll-like receptor 9 signaling pathway
    term:
      id: GO:0034162
      label: toll-like receptor 9 signaling pathway
    modifier: INCREASED
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "Serial testing also revealed fluctuating significant titers of anti-DNA antibodies in all three affected individuals."
    explanation: The anti-DNA autoantibodies seen in all three index patients.
  - reference: PMID:25548216
    reference_title: "Cutting edge: AIM2 and endosomal TLRs differentially regulate arthritis and autoantibody production in DNase II-deficient mice."
    supports: SUPPORT
    directness: INDIRECT
    evidence_source: MODEL_ORGANISM
    quote_role: PRIMARY_RESULT
    snippet: "whereas DNase II(-/-) Ifnar(-/-) mice also deficient in Unc93b, a chaperone required for TLR7/9 endosomal localization, fail to produce autoantibodies to nucleic acids"
    explanation: >-
      Endosomal TLR signaling, not STING, drives the anti-nucleic acid
      autoantibodies in the DNase II mouse. Indirect because it is a mouse
      genetic dissection applied to the human autoantibody finding.
  downstream:
  - target: Anti-dsDNA antibody positivity
    causal_link_type: DIRECT
- name: AIM2 Inflammasome Activation in Inflamed Joints
  description: >-
    A second cytosolic DNA sensor, the AIM2 inflammasome, contributes to the joint
    disease. In the DNase II-deficient mouse, loss of AIM2 reduces joint
    inflammation and caspase-1 activation while leaving the systemic inflammation
    AIM2-independent, so AIM2 is modeled as a tissue-specific contributor to the
    arthropathy rather than a driver of the whole syndrome. Its role in human
    DNASE2 deficiency is inferred from the mouse.
  role: consequence
  biological_scale: CELLULAR
  biological_processes:
  - preferred_term: AIM2 inflammasome complex assembly
    term:
      id: GO:0140970
      label: AIM2 inflammasome complex assembly
    modifier: INCREASED
  evidence:
  - reference: PMID:26114879
    reference_title: "AIM2 Drives Joint Inflammation in a Self-DNA Triggered Model of Chronic Polyarthritis."
    supports: SUPPORT
    directness: INDIRECT
    evidence_source: MODEL_ORGANISM
    quote_role: PRIMARY_RESULT
    snippet: "Arthritis-prone mice lacking AIM2 displayed strongly decreased signs of joint inflammation and associated histopathological findings."
    explanation: >-
      AIM2 deletion reduces the joint disease in the self-DNA arthritis model.
      Indirect because the sensor's role in human DNASE2 deficiency is inferred
      from the mouse.
  downstream:
  - target: Deforming Arthropathy
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
phenotypes:
- category: Hematologic
  name: Neonatal Anemia
  description: >-
    Severe non-regenerative anemia present at birth, requiring red blood cell
    transfusion. In the index patients it resolved over weeks to months; one had
    later-onset transfusion-dependent anemia in childhood.
  phenotype_term:
    preferred_term: Anemia
    term:
      id: HP:0001903
      label: Anemia
  frequency: VERY_FREQUENT
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "All three children demonstrated severe non-regenerative anemia and thrombocytopenia at birth necessitating red blood cell and platelet transfusions"
    explanation: Severe neonatal anemia in all three index patients.
- category: Hematologic
  name: Thrombocytopenia
  description: Neonatal thrombocytopenia requiring platelet transfusion, with persistent mild thrombocytopenia in some patients.
  phenotype_term:
    preferred_term: Thrombocytopenia
    term:
      id: HP:0001873
      label: Thrombocytopenia
  frequency: VERY_FREQUENT
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "All three children demonstrated severe non-regenerative anemia and thrombocytopenia at birth necessitating red blood cell and platelet transfusions"
    explanation: Neonatal thrombocytopenia in all three index patients.
- category: Hematologic
  name: Pancytopenia
  description: >-
    Neonatal pancytopenia (anemia, thrombocytopenia and neutropenia together) at
    presentation, the feature behind the disorder name. It was persistent and
    severe in the antenatal-onset case.
  phenotype_term:
    preferred_term: Pancytopenia
    term:
      id: HP:0001876
      label: Pancytopenia
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "Neonatal HSM, cholestatic hepatitis and pancytopenia requiring multiple RBC and platelet transfusions"
    explanation: Neonatal pancytopenia at presentation in the index patients.
  - reference: PMID:42491852
    reference_title: "Severe Antenatal Presentation of a Novel Dnase2 Mutation in a Preterm Omani Neonate: Expanding the Clinical Spectrum of an Ultra-Rare Interferonopathy."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "severe pancytopenia, with haemoglobin of 8.2 g/dL, platelet count of 12×10⁹/L, white blood cell count of 1.3×10⁹/L, and an absolute neutrophil count of 0"
    explanation: Severe persistent pancytopenia in the antenatal-onset case.
- category: Hematologic
  name: Circulating nucleated red blood cells
  description: >-
    An increased proportion of circulating erythroblasts with reticulocyte counts
    inappropriate for the degree of anemia, indicating ineffective erythropoiesis.
  phenotype_term:
    preferred_term: Circulating nucleated red blood cells
    term:
      id: HP:0033281
      label: Circulating nucleated red blood cells
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "Fresh blood samples from F1:V-1 and F1:V-3 demonstrated a marked increase in the percentage of circulating erythroblasts, whilst the number of reticulocytes was the same as in controls"
    explanation: Circulating erythroblasts in the index patients.
- category: Hepatic
  name: Hepatosplenomegaly
  description: Hepatosplenomegaly from the neonatal period, often with cholestatic hepatitis.
  phenotype_term:
    preferred_term: Hepatosplenomegaly
    term:
      id: HP:0001433
      label: Hepatosplenomegaly
  frequency: VERY_FREQUENT
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "together with hepatosplenomegaly and cholestatic hepatitis which resolved in the first few weeks of life"
    explanation: Neonatal hepatosplenomegaly with cholestatic hepatitis in the index patients.
- category: Hepatic
  name: Cholestasis
  description: Neonatal cholestatic hepatitis with conjugated hyperbilirubinemia.
  phenotype_term:
    preferred_term: Cholestasis
    term:
      id: HP:0001396
      label: Cholestasis
  evidence:
  - reference: PMID:42491852
    reference_title: "Severe Antenatal Presentation of a Novel Dnase2 Mutation in a Preterm Omani Neonate: Expanding the Clinical Spectrum of an Ultra-Rare Interferonopathy."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "conjugated hyperbilirubinemia (total bilirubin 300 µmol/L, conjugated fraction 255 µmol/L), consistent with cholestatic liver disease"
    explanation: Cholestatic liver disease with conjugated hyperbilirubinemia in the antenatal-onset case.
- category: Hepatic
  name: Hepatic Fibrosis
  description: Progressive liver fibrosis documented on biopsy in older children, in some cases with possible cirrhosis.
  phenotype_term:
    preferred_term: Hepatic fibrosis
    term:
      id: HP:0001395
      label: Hepatic fibrosis
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "Both these children also subsequently developed hepatosplenomegaly with fibrosis identified on liver biopsy"
    explanation: Liver fibrosis on biopsy in two index patients.
- category: Renal
  name: Membranoproliferative Glomerulonephritis
  description: >-
    Immune-complex membranoproliferative glomerulonephritis with proteinuria,
    developing in childhood without features of lupus nephritis in the index
    patients.
  phenotype_term:
    preferred_term: Membranoproliferative glomerulonephritis
    term:
      id: HP:0000793
      label: Membranoproliferative glomerulonephritis
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "with membranoproliferative glomerulonephritis documented in the younger affected child from Family 1 (F1; F1:V-3) and the proband from Family 2 (F2; F2:II-4)"
    explanation: Membranoproliferative glomerulonephritis in two index patients.
  sequelae:
  - target: Proteinuria
    causal_link_type: DIRECT
    description: The glomerulonephritis presents as proteinuria.
    evidence:
    - reference: PMID:29259162
      reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
      supports: SUPPORT
      directness: DIRECT
      evidence_source: HUMAN_CLINICAL
      quote_role: PRIMARY_RESULT
      snippet: "Proteinuria with features of MGN diagnosed at age 8 years"
      explanation: In the index patient the proteinuria was diagnosed together with the glomerulonephritis.
- category: Renal
  name: Proteinuria
  description: >-
    Proteinuria with onset between 6 and 10 years of age in all three index
    patients, including the oldest sibling, who was otherwise almost
    asymptomatic.
  phenotype_term:
    preferred_term: Proteinuria
    term:
      id: HP:0000093
      label: Proteinuria
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "the onset of proteinuria between the ages of 6 and 10 years"
    explanation: Proteinuria in all three index patients.
- category: Neurological
  name: Subcortical White Matter Lesions
  description: >-
    Patchy or small subcortical white matter hyperintensities on T2-weighted MRI
    in two of the three index patients, without overt neurological signs. One of
    them also had possible subtle basal ganglia calcification, which is not
    bound here because the source reports it only as possible. No cited source
    tests how the white matter change arises, so the node has no incoming
    causal edge.
  phenotype_term:
    preferred_term: Subcortical white matter hyperintensities on MRI
    term:
      id: HP:0030890
      label: Hyperintensity of cerebral white matter on MRI
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "F1:V-3 and F2:II-4 were recorded to show non-specific sub-cortical white matter lesions on cerebral imaging in the absence of overt neurological signs"
    explanation: Subcortical white matter lesions in two of three index patients.
- category: Neurological
  name: Learning Difficulties
  description: >-
    Mild to moderate learning difficulties at school in the same two index
    patients who had white matter lesions, after normal early milestones.
  phenotype_term:
    preferred_term: Learning difficulties
    term:
      id: HP:0001328
      label: Specific learning disability
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "although F1:V-3 exhibited learning difficulties necessitating extra help at school"
    explanation: Learning difficulties in an index patient; the clinical table records mild learning difficulties in the second.
- category: Growth
  name: Failure to Thrive
  description: >-
    Failure to thrive in childhood and adolescence, reported in the most severely
    affected index patient and in both patients with the intronic splice variant.
  phenotype_term:
    preferred_term: Failure to thrive
    term:
      id: HP:0001508
      label: Failure to thrive
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "Continued joint disease with Cushingoid features and failure to thrive, without signs of puberty"
    explanation: Failure to thrive in the index patient with the deforming arthropathy.
  - reference: PMID:41472683
    reference_title: "Type I interferon-mediated autoinflammation in two unrelated patients due to a proximal intronic splice site variant in DNASE2."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "They presented at birth with rash, thrombocytopenia, and anemia, later developing neutropenia, arthritis, failure to thrive, and systemic inflammation."
    explanation: Failure to thrive in both splice-variant patients.
- category: Endocrine
  name: Reduced Growth Hormone Response
  description: >-
    A reduced growth hormone response to arginine stimulation, suggestive of
    growth hormone deficiency, recorded at 17 years in one index patient.
  phenotype_term:
    preferred_term: Reduced growth hormone response to arginine stimulation
    term:
      id: HP:0000824
      label: Decreased response to growth hormone stimulation test
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "Reduced response to arginine suggestive of growth hormone deficiency noted at age 17 years"
    explanation: Reduced growth hormone stimulation response in an index patient.
- category: Musculoskeletal
  name: Deforming Arthropathy
  description: >-
    A non-destructive deforming arthropathy affecting multiple joints, refractory
    to broad immunosuppression and to anti-IL-1 and anti-TNF therapy in the index
    patient; later reports describe joint contractures.
  phenotype_term:
    preferred_term: Arthritis
    term:
      id: HP:0001369
      label: Arthritis
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "Starting at 8 years of age, F2:II-4 experienced the onset of a non-destructive, deforming arthropathy which has been refractory to broad-spectrum immunosuppression, anti-IL-1 receptor, anti-IL-1β and anti-TNFα therapies"
    explanation: The deforming arthropathy in the index patient.
- category: Musculoskeletal
  name: Joint contracture
  description: Progressive joint contractures reported in later patients, with features suggestive of osteopenia.
  phenotype_term:
    preferred_term: Joint contracture
    term:
      id: HP:0034392
      label: Joint contracture
  evidence:
  - reference: PMID:41472683
    reference_title: "Type I interferon-mediated autoinflammation in two unrelated patients due to a proximal intronic splice site variant in DNASE2."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "both patients presented with progressive joint contractures and features suggestive of osteopenia"
    explanation: Joint contractures and osteopenia in the two splice-variant patients.
- category: Inflammatory
  name: Recurrent Fever
  description: Recurrent febrile episodes beginning in childhood, with a raised acute-phase response.
  phenotype_term:
    preferred_term: Recurrent fever
    term:
      id: HP:0001954
      label: Recurrent fever
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "All three patients also experienced recurrent fevers starting between 5 and 7 years of age"
    explanation: Recurrent fevers in the index patients.
- category: Dermatologic
  name: Vasculitis in the skin
  description: Vasculitic and chilblain-like skin lesions reported in one index patient from adolescence.
  phenotype_term:
    preferred_term: Vasculitis in the skin
    term:
      id: HP:0200029
      label: Vasculitis in the skin
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "At the age of 13 years, this patient also developed vasculitic skin lesions"
    explanation: Vasculitic skin lesions in an index patient.
- category: Dermatologic
  name: Lipodystrophy
  description: Lipodystrophy of the limbs reported in an index patient and in later cases.
  phenotype_term:
    preferred_term: Lipodystrophy
    term:
      id: HP:0009125
      label: Lipodystrophy
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "Lipodystrophy of the limbs and chilblain-like lesions of the hands and feet since the age of 13 years"
    explanation: Lipodystrophy in an index patient.
- category: Dermatologic
  name: Chilblains
  description: >-
    Chilblain-like lesions of the hands and feet from adolescence in one index
    patient, a skin feature shared with other type I interferonopathies.
  phenotype_term:
    preferred_term: Chilblain-like lesions
    term:
      id: HP:0009710
      label: Chilblains
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "Lipodystrophy of the limbs and chilblain-like lesions of the hands and feet since the age of 13 years"
    explanation: Chilblain-like lesions of the hands and feet in an index patient.
- category: Immunologic
  name: Anti-dsDNA antibody positivity
  description: Fluctuating anti-DNA antibodies in all index patients, with antinuclear antibodies in some, reflecting a lupus-like autoimmune component.
  phenotype_term:
    preferred_term: Anti-dsDNA antibody positivity
    term:
      id: HP:0020151
      label: Anti-dsDNA antibody positivity
  frequency: VERY_FREQUENT
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "Serial testing also revealed fluctuating significant titers of anti-DNA antibodies in all three affected individuals."
    explanation: Anti-DNA antibodies in all three index patients.
- category: Laboratory
  name: Type I Interferon Signature
  description: >-
    A peripheral blood type I interferon signature with raised interferon alpha
    protein and upregulated interferon-stimulated genes, the shared biomarker of
    the type I interferonopathies.
  phenotype_term:
    preferred_term: Increased circulating Interferon-alpha concentration
    term:
      id: HP:0034513
      label: Increased circulating Interferon-alpha concentration
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "we recorded increased levels of interferon alpha protein in serum and plasma from all three patients, comparable to levels observed in other type I interferonopathies"
    explanation: Raised interferon alpha protein in all index patients.
- category: Laboratory
  name: Elevated erythrocyte sedimentation rate
  description: A persistently raised erythrocyte sedimentation rate, with C-reactive protein variably elevated.
  phenotype_term:
    preferred_term: Elevated erythrocyte sedimentation rate
    term:
      id: HP:0003565
      label: Elevated erythrocyte sedimentation rate
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "All three patients demonstrated a persistent increase in erythrocyte sedimentation rate (ESR)"
    explanation: Persistently raised ESR in the index patients.
- category: Prenatal
  name: Hydrops fetalis
  description: >-
    Antenatal presentations with fetal anemia and hydrops fetalis, reported for a
    fetus in the index Family 1 and for the antenatal-onset case with intrauterine
    growth restriction and hypertrophic cardiomegaly.
  phenotype_term:
    preferred_term: Hydrops fetalis
    term:
      id: HP:0001789
      label: Hydrops fetalis
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "F1:V-2 denotes a fetus delivered in late pregnancy with hydrops fetalis, hepatosplenomegaly and petechiae."
    explanation: Hydrops fetalis in a fetus of an index family.
- category: Endocrine
  name: Type I diabetes mellitus
  description: Autoantibody-negative insulin-dependent diabetes mellitus in one index patient from age 5.
  phenotype_term:
    preferred_term: Type I diabetes mellitus
    term:
      id: HP:0100651
      label: Type I diabetes mellitus
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "F1:V-3 developed antibody-negative insulin-dependent diabetes mellitus at 5 years of age"
    explanation: Insulin-dependent diabetes in one index patient.
- category: Immunologic
  name: Hypogammaglobulinemia
  description: Hypogammaglobulinemia requiring immunoglobulin replacement in one index patient, with progressive CD4+ and CD8+ lymphopenia.
  phenotype_term:
    preferred_term: Decreased circulating immunoglobulin concentration
    term:
      id: HP:0004313
      label: Decreased circulating immunoglobulin concentration
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "frank hypogammaglobulinemia from 7 years of age requiring IVIG; progressive CD4+ and CD8+ lymphopenia first recorded at age 6 years"
    explanation: Hypogammaglobulinemia and lymphopenia in an index patient.
biochemical:
- name: Interferon-stimulated gene score
  presence: Elevated
  context: >-
    An elevated interferon-stimulated gene score in whole blood is the shared
    laboratory signature of the type I interferonopathies and was used to
    ascertain the index patients, who overexpressed a six-ISG panel (IFI27,
    IFI44L, IFIT1, ISG15, RSAD2, SIGLEC1).
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "demonstrating increased expression of a panel of six interferon-stimulated genes (ISGs) (IFI27, IFI44L, IFIT1, ISG15, RSAD2, and SIGLEC1)"
    explanation: The ISG panel used to detect the interferon signature in the index patients.
- name: Hyperferritinemia
  presence: Elevated
  context: >-
    Markedly raised ferritin with hypofibrinogenemia and cytopenias produced an
    HLH-like picture in the antenatal-onset case, although full HLH 2004 criteria
    were not met.
  evidence:
  - reference: PMID:42491852
    reference_title: "Severe Antenatal Presentation of a Novel Dnase2 Mutation in a Preterm Omani Neonate: Expanding the Clinical Spectrum of an Ultra-Rare Interferonopathy."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "ferritin levels were markedly elevated (6886 ug/L)"
    explanation: Marked hyperferritinemia in the HLH-like antenatal-onset presentation.
diagnosis:
- name: Exome sequencing for biallelic DNASE2 variants
  description: >-
    The diagnosis rests on finding biallelic DNASE2 variants by exome sequencing,
    with functional confirmation of reduced DNase II activity in patient cells.
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "We performed whole-exome sequencing using DNA from the three patients and their parents"
    explanation: Exome sequencing identified the biallelic DNASE2 genotypes.
- name: Type I interferon signature testing
  description: >-
    An interferon-stimulated gene score or interferon alpha measurement supports
    the diagnosis and tracks disease activity, as for other type I
    interferonopathies.
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "By systematic screening using a panel of interferon-stimulated genes we identify two siblings and a singleton"
    explanation: ISG screening is how the index patients were ascertained.
treatments:
- name: JAK Inhibition (Ruxolitinib)
  description: >-
    JAK1/2 inhibition with ruxolitinib blocks the JAK-STAT signaling driven by
    type I interferon. It has been followed by clinical and laboratory
    improvement, including recovery of cytopenias, resolution of cholestasis and
    reduction of inflammation, in reported patients, including a preterm neonate.
    In the index study, ruxolitinib reduced STAT1 and STAT3 phosphorylation in
    patient cells in vitro.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: targeted therapy
    term:
      id: NCIT:C93352
      label: Targeted Therapy
    therapeutic_agent:
    - preferred_term: ruxolitinib
      term:
        id: CHEBI:66919
        label: ruxolitinib
  target_mechanisms:
  - target: Type I Interferon Overproduction and JAK-STAT Signaling
    description: Blocks JAK1/2 downstream of the type I interferon receptor, interrupting the interferon-driven signaling.
  evidence:
  - reference: PMID:42491852
    reference_title: "Severe Antenatal Presentation of a Novel Dnase2 Mutation in a Preterm Omani Neonate: Expanding the Clinical Spectrum of an Ultra-Rare Interferonopathy."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "treatment with ruxolitinib in our patient resulted in marked clinical and laboratory improvement, supporting its role as a potentially disease-modifying therapy in Dnase2 deficiency"
    explanation: Clinical and laboratory improvement on ruxolitinib in the antenatal-onset case.
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: INDIRECT
    evidence_source: IN_VITRO
    quote_role: PRIMARY_RESULT
    snippet: "Increased phosphorylation of STAT1 and STAT3 observed in cultured lymphocytic-enriched fractions from F1:V-1 compared to a healthy control (HC), treated or not with the JAK1/2 inhibitor ruxolitinib."
    explanation: >-
      Ruxolitinib reduced STAT1/STAT3 phosphorylation in patient cells in vitro,
      the mechanistic rationale for JAK inhibition. Indirect because it is an
      ex vivo cellular readout rather than a clinical outcome.
- name: Supportive Transfusion
  description: Red blood cell and platelet transfusions for the neonatal cytopenias.
  therapeutic_modality: OTHER
  treatment_term:
    preferred_term: red blood cell and platelet transfusion
    term:
      id: NCIT:C15192
      label: Blood Transfusion
  target_mechanisms:
  - target: Neonatal Anemia
    description: Red cell transfusion corrects the transfusion-dependent neonatal anemia.
  - target: Thrombocytopenia
    description: Platelet transfusion supports the neonatal thrombocytopenia.
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "necessitating red blood cell and platelet transfusions"
    explanation: Transfusion support for the neonatal cytopenias.
- name: Immunoglobulin Replacement Therapy
  description: Intravenous immunoglobulin for the hypogammaglobulinemia seen in one index patient.
  therapeutic_modality: PROTEIN_REPLACEMENT
  treatment_term:
    preferred_term: Intravenous Immunoglobulin Therapy
    term:
      id: NCIT:C121331
      label: Intravenous Immunoglobulin Therapy
  evidence:
  - reference: PMID:29259162
    reference_title: "Type I interferon-mediated autoinflammation due to DNase II deficiency."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "frank hypogammaglobulinemia from 7 years of age requiring IVIG"
    explanation: Immunoglobulin replacement for the hypogammaglobulinemia in an index patient.
prevalence:
- population: Worldwide
  measure_type: CASES_IN_LITERATURE
  prevalence_class: ULTRA_RARE
  notes: >-
    An ultra-rare disorder. The 2017 index report described three patients from
    two families; a 2025 preprint called the total six patients before adding two
    more, and further single cases have since been reported, so fewer than fifteen
    patients are published. No population estimate exists, so rate_per_100000 is
    left unset.
  evidence:
  - reference: PMID:41472683
    reference_title: "Type I interferon-mediated autoinflammation in two unrelated patients due to a proximal intronic splice site variant in DNASE2."
    supports: SUPPORT
    directness: DIRECT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: "To date, only 6 patients have been reported, with clinical manifestations predominantly including congenital anemia, hepatosplenomegaly, and systemic inflammation"
    explanation: The reported patient total before the two cases this preprint adds.
animal_models:
- name: Dnase2 knockout mouse
  species: Mus musculus
  genotype: Dnase2-/- (constitutive null)
  publication: PMID:11375492
  description: >-
    Constitutive DNase II-null mice die in late embryogenesis or at birth from a
    severe anemia, because macrophages at the site of fetal liver definitive
    erythropoiesis cannot digest the nuclei expelled by erythroid precursors. The
    model reproduces the macrophage DNA accumulation and the lethal fetal anemia
    but not the full postnatal human syndrome, which is only seen once the
    embryonic lethality is bypassed.
  modeled_mechanisms:
  - target: Interferon-Driven Suppression of Fetal and Neonatal Erythropoiesis
    relationship: RECAPITULATES
    fidelity: MODERATE
    model_scale: ORGANISM
    description: Reproduces the type I interferon-dependent failure of definitive erythropoiesis.
    limitations: >-
      The mouse null is embryonic-lethal, so it models the fetal anemia rather
      than the resolving neonatal anemia and later multisystem disease of the
      hypomorphic human alleles.
    evidence:
    - reference: PMID:15568025
      reference_title: "Lethal anemia caused by interferon-beta produced in mouse embryos carrying undigested DNA."
      supports: SUPPORT
      directness: DIRECT
      evidence_source: MODEL_ORGANISM
      quote_role: PRIMARY_RESULT
      snippet: "the inability to degrade DNA derived from erythroid precursors results in interferon-beta production that induces expression of a specific set of interferon-responsive genes associated with embryonic lethality in DNase II-deficient mice"
      explanation: The interferon-driven lethal anemia this node represents.
- name: Dnase2 Ifnar1 double-knockout mouse
  species: Mus musculus
  genotype: Dnase2-/- Ifnar1-/- (type I interferon receptor double knockout)
  publication: PMID:17066036
  description: >-
    Removing the type I interferon receptor rescues the embryonic lethality, and
    the surviving mice develop a chronic TNF-dependent polyarthritis resembling
    rheumatoid arthritis, with cytopenia, extramedullary hematopoiesis and liver
    fibrosis. This model captures the postnatal interferon-independent
    inflammatory arm, including the arthropathy.
  modeled_mechanisms:
  - target: STING-TBK1-Driven Proinflammatory Cytokine Production
    relationship: RECAPITULATES
    fidelity: MODERATE
    model_scale: ORGANISM
    description: Reproduces the TNF-driven inflammatory arthritis of the interferon-independent arm.
    limitations: >-
      The arthritis arm is studied with the interferon receptor deleted, so it
      models the interferon-independent cytokine route in isolation rather than
      the combined human disease in which interferon signaling is intact.
    evidence:
    - reference: PMID:17066036
      reference_title: "Chronic polyarthritis caused by mammalian DNA that escapes from degradation in macrophages."
      supports: SUPPORT
      directness: DIRECT
      evidence_source: MODEL_ORGANISM
      quote_role: PRIMARY_RESULT
      snippet: "DNase II-/-IFN-IR-/- mice and mice with an induced deletion of the DNase II gene develop a chronic polyarthritis resembling human rheumatoid arthritis"
      explanation: The TNF-dependent polyarthritis this model contributes.
  - target: Hepatic Fibrosis
    relationship: RECAPITULATES
    fidelity: MODERATE
    model_scale: ORGANISM
    description: >-
      The double-knockout mouse reproduces the liver fibrosis seen in patients,
      together with cytopenia and extramedullary hematopoiesis.
    limitations: >-
      The interferon receptor is deleted in this model, so its liver fibrosis
      arises without type I interferon signaling, whereas the patients have an
      intact interferon response. The cited comparison does not report renal
      pathology, so the model is not linked to the glomerulonephritis node.
    evidence:
    - reference: PMID:31464028
      reference_title: "Role of Interferon-gamma-Producing Th1 Cells in a Murine Model of Type I Interferon-Independent Autoinflammation Resulting From DNase II Deficiency."
      supports: SUPPORT
      directness: DIRECT
      evidence_source: MODEL_ORGANISM
      quote_role: PRIMARY_RESULT
      snippet: "many of the disease features found in DNase II-deficient patients were recapitulated, including cytopenia, extramedullary hematopoiesis, and liver fibrosis"
      explanation: The model reproduces the liver fibrosis of DNase II-deficient patients.
notes: >-
  Lump/split. This is a single leaf Disease entry for the DNASE2-defined type I
  interferonopathy (MONDO:0800132, OMIM:619858). MONDO places the term directly
  under hereditary disease with no disease children and one causal gene, and no
  other kb/ entry covers DNASE2, so a single-gene leaf entry is the right level.

  Mechanism and module conformance. DNase II acts in the lysosome, so the entry
  conforms to the first two nodes of the lysosomal substrate accumulation module
  (hydrolase deficiency, substrate accumulation) with DNA as the stored
  substrate, then diverges: the damage is driven by innate DNA sensing rather
  than storage cytotoxicity, so it does not conform to that module's downstream
  cytotoxicity nodes. From the accumulated DNA it conforms to the cGAS-STING
  pathway activation module at the sensing and TBK1-IRF3 nodes, which is the
  DNASE2-specific lysosomal substitution the module's notes anticipate (a nuclease
  no longer clears self DNA). The cGAS and STING dependence is established in
  mouse genetics (cGas or Sting deletion rescues both the embryonic lethality and
  the arthritis); the human patient data show the interferon signature and
  JAK-STAT activation but do not themselves prove the sensor, so the sensor edges
  carry mouse evidence and the interferon node carries human evidence.

  Two parallel inflammatory arms. The arthropathy and much of the systemic
  inflammation run through an interferon-independent STING-TBK1-NF-kB cytokine arm
  (TNF, IL-6), shown in mice by a STING mutant that cannot induce interferon but
  still causes TNF/IL-6-dependent arthritis, and the autoantibody arm depends on
  endosomal TLRs (Unc93b1) rather than STING. These are modeled as separate
  downstream routes from the accumulated DNA, not as consequences of the
  interferon node, so the entry does not overstate a single interferon mechanism.

  Deliberately uncited claims. The route by which lysosomal DNA reaches cytosolic
  cGAS is not resolved in the cited sources and is left as an open statement in the
  cGAS node description rather than asserted. The baricitinib reports (Hong et al.,
  PMID:31775019) are described in the literature but that paper has no fetchable
  abstract in the reference cache, so only ruxolitinib, which has verifiable
  quotes, is curated as a treatment; baricitinib is mentioned in prose only.
📚

References & Deep Research

References

1
PMID:29259162
Type I interferon-mediated autoinflammation due to DNase II deficiency.
No top-level findings curated for this source.

Deep Research

1

Deep research results are used as seeds for research; they do not undergo the same validation as the main records and may contain errors. How we use deep research.

Evaluations and curation notes (1)

Create: DNASE2 Deficiency · 2026-10-14T13:15:28Z · View source

De novo curation of DNASE2 deficiency (MONDO:0800132, OMIM:619858), an autosomal recessive type I interferonopathy caused by biallelic loss of lysosomal DNase II. Lump/split: single leaf Disease entry (entry_type DISEASE); MONDO term has one causal gene, no disease children, and no existing kb/ entry covers DNASE2. Stub deleted. One OpenScientist deep-research report was used (research/DNASE2_Deficiency-deep-research-openscientist.md). The recipe's own term-validation step timed out reaching OLS, so the run exited code 3; both retro-fit validations were re-run in the worktree with just validate-research-reference and just validate-research-terms. Report reference validation: 18/18 resolved, 0 off topic, 0 unverifiable. Term validation: 42/46 resolved (4 unverifiable prefixes), 2 named-as-different (both benign: MONDO:0800132 and UBERON:0002217 paraphrases) and 7 worth-a-second-look (all benign paraphrases of the canonical labels, e.g. Severe anemia for HP:0001903 Anemia). No report-suggested CURIE was bound unchecked; every ontology term was looked up in OLS when written. just preflight-dr research/DNASE2_Deficiency-deep-research-openscientist.md MONDO:0800132 returned WARN: DNASE2 is mentioned 43 times and the OMIM identifier matches MONDO (619858); the warning is that TNF is the second most mentioned gene (31). Those TNF passages describe the interferon-independent, TNF-driven arthritis of Dnase2/Ifnar1 double-knockout mice, which is part of this disease's mechanism, not a second disease entity, so no report section was excluded. Content curated chiefly from primary literature read directly: PMID:29259162 (Rodero 2017 Nat Commun, three index patients, the defining clinical and mechanistic source), PMID:41472683 (2025 Research Square preprint, c.511+5G>A splice variant, two patients, ruxolitinib response, patient-total context; cited as a preprint because no peer-reviewed version was found), PMID:42491852 (2026 Cureus, antenatal/hydrops presentation, ruxolitinib), PMID:41608114 (IUIS 2024 classification Table 7 row). Mouse mechanism: PMID:11375492 (DNase II required for fetal-liver definitive erythropoiesis), PMID:15568025 (IFN-beta-driven lethal anemia rescued by Ifnar deletion), PMID:17066036 (Dnase2-/-Ifnar1-/- TNF-dependent polyarthritis), PMID:26371324 (cGAS deletion rescues DNaseII-/- autoimmunity; cGAMP accumulation), PMID:23132945 (STING loss rescues both phenotypes), PMID:34901991 (STING-TBK1 interferon-independent arthritis arm), PMID:26114879 (AIM2 drives joint inflammation), PMID:25548216 (endosomal TLR/Unc93b1 drives autoantibodies), PMID:31464028 (Dnase2-/-Ifnar1-/- recapitulates human features). Pathophysiology built as a causal chain conforming to two modules: lysosomal_substrate_accumulation (first two nodes only, DNA as stored substrate) and cgas_sting_pathway_activation (sensing and TBK1-IRF3 nodes, the DNASE2-specific lysosomal-nuclease substitution the module notes anticipate). Two parallel inflammatory arms modeled separately: interferon-dependent (JAK-STAT, erythropoiesis suppression, organ inflammation) and interferon-independent STING-TBK1-NF-kB cytokine arm (TNF/IL-6, arthropathy), plus an endosomal-TLR autoantibody arm and an AIM2 joint arm. Phenotypes wired into the graph via bare-name downstream targets. Two animal_models with modeled_mechanisms (Dnase2-/- and Dnase2-/-Ifnar1-/-). Added DNASE2 Deficiency as a member of kb/groupings/Autoinflammatory_Disorder_IEIs.yaml (IUIS Table 7); membership criterion SATISFIED. References rejected/not used: PMID:31775019 (Hong et al. JAK inhibition / baricitinib) had no fetchable abstract in the cache (content unavailable), so baricitinib is mentioned in prose only and only ruxolitinib, with verifiable quotes, is curated as a treatment. PMID:32222431 reports a single heterozygous DNASE2 variant, which does not fit the recessive model, so that case is noted but not counted. Validation (all pass): just validate (schema OK, term validation passed, 53/53 snippets verified, 54 titles), just validate-disorders (batched, 0 issues), count-verified-snippets 53/53, check-entity-refs OK, check-causal-targets OK (no new dangling), check-duplicate-keys OK, check-enum-values OK, check-block-scalar-comments 0, check-coarse-phenotypes no new, check-snippet-length 0 new (fixed one 2-word IVIG snippet), check-title-snippets OK, check-genereviews NO_CHAPTER (no GeneReviews chapter for DNASE2 deficiency; offline check), normalize-cache and check-term-cache-integrity clean, validate-grouping-batch passed. just check-genereviews --online crashed with a ValueError in src/dismech/bookshelf.py rank() (match kind not in MATCH_KINDS); the offline check ran fine.

OpenScientist ▸
DNASE2 Deficiency (Autoinflammatory–Pancytopenia Syndrome, AIPCS): Comprehensive Disease Characteristics Report
openscientist-autonomous 18 citations 2026-10-14T13:05:22.786173

DNASE2 Deficiency (Autoinflammatory–Pancytopenia Syndrome, AIPCS): Comprehensive Disease Characteristics Report

Disease: DNASE2 Deficiency / Autoinflammatory–Pancytopenia Syndrome (AIPCS) MONDO: MONDO:0800132 · OMIM: #619858 · Category: Mendelian (autosomal recessive)

Evidence base: This is an ultra-rare disease with a small primary human literature (first described 2017). Mechanistic depth comes largely from mouse genetics, which recapitulate the human phenotype well. Evidence-source types are flagged throughout as [human], [mouse], [in vitro], or [computational].

Summary

DNASE2 deficiency — formally designated Autoinflammatory–Pancytopenia Syndrome (AIPCS; MONDO:0800132, OMIM #619858) — is an ultra-rare, autosomal-recessive monogenic type I interferonopathy caused by biallelic loss-of-function variants in DNASE2 (chromosome 19p13.13). The gene encodes DNase II-alpha, a 360-amino-acid ubiquitously expressed lysosomal acid endonuclease that degrades DNA derived from apoptotic cells and from nuclei expelled by erythroblasts during definitive erythropoiesis. When this enzyme is lost, undegraded self-DNA accumulates within macrophage lysosomes and leaks to the cytosol, where it is sensed by the TLR-independent cGAS–STING–TBK1–IRF3/7 axis. The result is constitutive overproduction of type I interferon (principally IFN-β), accompanied by a separable TNF-α–driven inflammatory program, which together produce a congenital/neonatal-onset multisystem autoinflammatory disease.

The core human phenotype, first defined by Rodero et al. in 2017, comprises severe neonatal anemia, membranoproliferative glomerulonephritis, liver fibrosis, deforming arthropathy, and anti-DNA antibodies, all on a background of a strong blood interferon signature and constitutive STAT1/STAT3 phosphorylation. Subsequent case reports have expanded the spectrum to include an extremely severe antenatal presentation (fetal hydrops, intrauterine growth restriction, cardiomyopathy, persistent pancytopenia, hepatosplenomegaly, cholestatic jaundice, and hemophagocytic lymphohistiocytosis–like features with marked hyperferritinemia), as well as recurrent fevers, vasculitic skin lesions/chilblains, gastrointestinal inflammation, lipodystrophy, and subcortical white-matter lesions.

The disease mechanism is exceptionally well validated by Dnase2-null mouse genetics: embryonic lethality from IFN-β–driven lethal anemia is rescued by crossing onto an Ifnar-null background, sensing is TLR-independent, and the surviving mice develop a chronic, TNF-α–dependent, rheumatoid-arthritis-like polyarthritis driven in part by IFN-γ–producing Th1 cells independent of type I IFN. Diagnosis rests on the blood interferon signature, reduced DNase II enzymatic activity, and exome/genome sequencing. Mechanism-directed treatment centers on JAK1/2 inhibitors (baricitinib, ruxolitinib) to suppress IFN signaling, with a strong preclinical rationale for anti-TNF therapy against the arthritis component and hematopoietic stem-cell transplantation as a conceptual cure.

Key Findings

F001 — DNASE2 deficiency is an autosomal-recessive type I interferonopathy caused by biallelic loss-of-function DNASE2 variants [human]

The defining human study is Rodero et al. (2017), which identified biallelic DNASE2 mutations in three patients from two families, each with loss of DNase II endonuclease activity, elevated IFN-alpha protein measured by digital ELISA, enhanced interferon signaling on RNA-Seq, and constitutive upregulation of phosphorylated STAT1 and STAT3 in patient lymphocytes and monocytes. In the authors' words: "In both families we identify biallelic mutations in DNASE2, associated with a loss of DNase II endonuclease activity. We record increased interferon alpha protein levels using digital ELISA, enhanced interferon signaling by RNA-Seq analysis and constitutive upregulation of phosphorylated STAT1 and STAT3 in patient lymphocytes and monocytes" PMID: 29259162. Subsequent reports confirmed additional biallelic/homozygous pathogenic variants, including a proximal intronic splice-site variant causing type I interferon-mediated autoinflammation in two unrelated patients PMID: 41472683, which describes DNase II as "a lysosomal endonuclease critical for degrading DNA during erythropoiesis and apoptosis" and confirms recessive biallelic loss-of-function inheritance. This establishes the disease as a monogenic, recessive interferonopathy with a clear molecular signature.

F002 — Core clinical phenotype: neonatal anemia, membranoproliferative glomerulonephritis, liver fibrosis, deforming arthropathy, and anti-DNA antibodies [human]

The index cohort variably demonstrated a stereotyped multisystem picture: "we identify two siblings and a singleton variably demonstrating severe neonatal anemia, membranoproliferative glomerulonephritis, liver fibrosis, deforming arthropathy and increased anti-DNA antibodies" PMID: 29259162. Peripheral blood showed increased erythroblasts and a hematological-disease transcriptomic signature, linking the anemia directly to the enzyme's erythropoietic role. The 2026 Omani neonatal report expanded the severe end of the spectrum, with disease "manifesting antenatally with fetal hydrops, intrauterine growth restriction, and cardiomyopathy. Postnatally, the infant developed persistent pancytopenia, hepatosplenomegaly, cholestatic jaundice, and hemophagocytic lymphohistiocytosis-like features, including marked hyperferritinemia" PMID: 42491852.

F003 — Mechanism: undegraded self-DNA drives cGAS–STING-dependent type I IFN, with an IFNAR-independent inflammatory branch [mouse, in vitro]

Mouse genetics establish an unambiguous causal chain. Dnase2-null embryos accumulate undigested DNA in macrophages and die in utero from IFN-β–driven lethal anemia; crucially, "When the DNase II-deficient mice were crossed with mice deficient in type I interferon receptor, the resultant 'double-mutant' mice were born healthy" PMID: 15568025, proving type I IFN signaling via IFNAR is causally required for lethal anemia. Sensing is TLR-independent: "The ablation of Toll-like receptor (TLR) 3 and 9, or their adaptor molecules (MyD88 and TRIF), had no effect on the lethality of the DNase II(-/-) mice. These results indicate that there is a TLR-independent sensing mechanism" PMID: 16301743, implicating cytosolic cGAS–STING. This is confirmed functionally: DNase2-deficient patient fibroblasts have a constitutively primed cGAS–STING–TBK1 pathway PMID: 33916318. A type I IFN-independent branch also contributes — in Dnase2/Ifnar double-knockout mice, chronic polyarthritis is driven by IFN-γ–producing Th1 cells PMID: 31464028 — and STING contributes to paradoxical ectopic bone formation PMID: 27740718.

F004 — DNase II acts non-cell-autonomously in macrophages to degrade erythroid-expelled nuclear DNA; it is essential for definitive erythropoiesis [mouse]

Kawane et al. (2001) showed that DNase II-null mice are not born, dying of severe anemia, and that transfer of mutant fetal liver cells into irradiated wild-type mice generated mature red blood cells, demonstrating a non-cell-autonomous mechanism. Histochemistry localized the critical enzyme source: "the critical cellular sources of DNase II are macrophages present at the site of definitive erythropoiesis in the fetal liver. Thus, DNase II in macrophages appears to be responsible for destroying the nuclear DNA expelled from erythroid precursor cells" PMID: 11375492. This directly explains the anemia: central nurse macrophages in erythroblastic islands normally phagocytose and digest the extruded erythroblast nucleus, and without DNase II this DNA accumulates and triggers IFN.

F005 — Two-branch mechanism: IRF3/7-dependent IFN-β drives embryonic anemia; TNF-α drives chronic polyarthritis (IFN-independent) [mouse]

Kawane et al. (2006) found that Dnase2⁻/⁻ Ifnar⁻/⁻ mice (and mice with induced DNase II deletion) develop chronic, destructive polyarthritis resembling rheumatoid arthritis, with high serum anti-CCP antibody, rheumatoid factor, and MMP-3. "Early in the pathogenesis, expression of the gene encoding tumour necrosis factor (TNF)-alpha was upregulated in the bone marrow, and administration of anti-TNF-alpha antibody prevented the development of arthritis" PMID: 17066036. Okabe et al. (2008) dissected the transcriptional logic: "DNase II(-/-)IRF3(-/-)IRF7(-/-) mice do not suffer from anemia, but they still produce TNF-alpha, and age-dependently develop chronic polyarthritis" PMID: 18991290. Thus two separable gene-induction programs flow from the same undegraded DNA: an IRF3/7-dependent IFN-β program (anemia) and an IRF3/7-independent TNF-α program (arthritis). HMGB-1 is an additional pathogenic mediator in the arthritis model, with HMGB-1 blockade ameliorating disease PMID: 20533288.

F006 — DNASE2 gene/protein: chromosome 19, a 360-aa ubiquitously expressed lysosomal acid endonuclease [human]

Yasuda et al. (1998) cloned the human DNase II cDNA: "an open reading frame of 1080 bases, which encoded a single polypeptide of 360 amino acids (signal peptide, 16; propeptide, 91; mature protein, 253)" and established that "DNase II is ubiquitously expressed in human tissues, and the DNase II gene (DNASE2) was assigned to chromosome 19" PMID: 9446563. The enzyme is an acid, divalent-cation-independent endonuclease active at lysosomal pH, with a cDNA organization resembling the lysosomal cathepsin families.

F007 — Treatment: JAK inhibitors as targeted therapy; anti-TNF rationale for arthritis; HSCT conceptually curative [human, mouse]

In the severe antenatal case, "Whole-exome sequencing enables definitive diagnosis, and Janus kinase inhibitors have emerged as targeted immunomodulatory therapy" PMID: 42491852. JAK1/2 inhibitors (baricitinib, ruxolitinib) reduce the interferon signature and systemic/dermatologic inflammation across type I interferonopathies, with greater benefit in mild/intermediate phenotypes and earlier initiation PMID: 41871482. The mouse arthritis branch is prevented by "administration of anti-TNF-alpha antibody" PMID: 17066036. Allogeneic HSCT achieved cure in the related interferonopathy SAVI PMID: 42137281, supporting a hematopoietic-targeted curative strategy since DNase II's critical role is in macrophages.

F008 — DNASE2 is loss-of-function tolerant in gnomAD, consistent with recessive inheritance and healthy carriers [computational]

gnomAD constraint metrics for DNASE2 (ENSG00000105612) indicate tolerance of heterozygous loss of function: pLI ≈ 1.5×10⁻⁸ (effectively 0), observed/expected LoF = 0.87 (90% CI 0.64–1.21), lof_z = 0.59, mis_z = 0.81. This is exactly the constraint signature expected of a recessive disease gene where carriers are unaffected. Verified identifiers (via mygene.info): HGNC:2960, Entrez 1777, Ensembl ENSG00000105612, locus 19p13.13, UniProt O00115; mouse ortholog Dnase2a (Entrez 13423, MGI:1329019).

F009 — Authoritative identifiers and ontology annotations [computational]

EBI OLS4 gives MONDO:0800132 the official label "autoinflammatory-pancytopenia syndrome due to DNASE2 deficiency," with cross-references OMIM:619858 (phenotype), UMLS:C5676977, and MedGen:1803642. The gene alias "AIPCS" is the phenotype acronym (Autoinflammatory–Pancytopenia Syndrome). UniProt O00115 GO annotations include GO:0004531 (deoxyribonuclease II activity, molecular function), GO:0006309 (apoptotic DNA fragmentation), GO:0043277 (apoptotic cell clearance), GO:0005764 (lysosome), and GO:0070062 (extracellular exosome). The catalytic activity is endonucleolytic cleavage to nucleoside 3′-phosphate / 3′-phospho-oligonucleotide products; the enzyme is an acidic-pH dsDNA-preferring hydrolase necessary for definitive erythropoiesis.

F010 — Authoritative HPO phenotype spectrum expands features beyond the index report [human]

The JAX HPO annotation of OMIM:619858 (MONDO:0800132) catalogs a broad spectrum: severe anemia (HP:0001903), thrombocytopenia (HP:0001873), pancytopenia (HP:0001876), hemophagocytosis (HP:0012156), hepatosplenomegaly (HP:0001433), hepatic fibrosis (HP:0001395), cholestatic liver disease (HP:0002611), membranoproliferative glomerulonephritis (HP:0000793), proteinuria (HP:0000093), arthropathy (HP:0003040), recurrent fever/fever (HP:0001954/HP:0001945), chilblains (HP:0009710), granuloma (HP:0032252), chronic diarrhea (HP:0002028), intestinal inflammation (HP:4000055), failure to thrive/growth delay (HP:0001508/HP:0001510), motor delay (HP:0001270/HP:0002194), lipodystrophy (HP:0009125), type 1 diabetes (HP:0100651), and severe EBV infection (HP:0031693). Onset is congenital (HP:0003577)/neonatal (HP:0003623); inheritance is autosomal recessive (HP:0000007). The OMIM description additionally notes vasculitic skin lesions and subcortical white-matter lesions on brain imaging.

Section-by-Section Report

1. Disease Information

Overview. DNASE2 deficiency is a monogenic autosomal-recessive systemic autoinflammatory disorder classified as a type I interferonopathy. Loss of the lysosomal enzyme DNase II leads to accumulation of undegraded self-DNA, chronic type I interferon production, and multisystem inflammation beginning before or at birth.

Key identifiers.

Resource Identifier
MONDO MONDO:0800132 ("autoinflammatory-pancytopenia syndrome due to DNASE2 deficiency")
OMIM (phenotype) #619858
UMLS C5676977
MedGen 1803642
Gene (HGNC) DNASE2, HGNC:2960
Entrez Gene 1777
Ensembl ENSG00000105612
UniProt O00115
Orphanet Not established as a distinct ORPHA code at time of research (ultra-rare; <10 reported families)
ICD-10/ICD-11 No specific code; falls under autoinflammatory/immunodeficiency groupings
MeSH No dedicated descriptor; indexed via DNASE2 and "interferon type I"

Synonyms / alternative names: AIPCS; Autoinflammatory–Pancytopenia Syndrome; DNase II deficiency; DNase II-alpha deficiency; type I interferon-mediated autoinflammation due to DNase II deficiency.

Information source: Disease-level knowledge is derived from a small number of individual patient reports (aggregated into OMIM/MONDO/HPO disease-level resources) plus extensive Dnase2-null mouse model data. This is not EHR/population-derived; it is individual-patient and model-organism derived.

2. Etiology

Causal factors. The disease is purely genetic: biallelic (homozygous or compound heterozygous) loss-of-function variants in DNASE2 PMID: 29259162. There is no infectious or primary environmental cause.

Genetic risk factors. The only established risk factor is inheritance of two loss-of-function DNASE2 alleles. DNASE2 is LoF-tolerant in gnomAD (pLI ≈ 0, LOEUF upper bound 1.21), so heterozygous carriers are healthy (F008). Consanguinity increases risk of homozygosity, as expected for any ultra-rare recessive disorder; several reported cases are from consanguineous or isolated-population backgrounds (e.g., the Omani neonate, PMID: 42491852).

Environmental risk / protective factors. None established. As a Mendelian monogenic disorder, environmental exposures are not primary determinants. Mechanistically, a bacterial/LPS (TLR4) stimulus can amplify IFN output in cells with a primed cGAS–STING pathway PMID: 33916318, suggesting infections could trigger flares, but this is inferred rather than demonstrated clinically.

Protective genetic factors. In mice, loss of IFNAR, STING, or IRF3/7 rescues or attenuates disease — these are experimental "protective" modifiers establishing the pathway, not naturally occurring human protective alleles (F003, F005).

Gene–environment interactions. Not formally characterized in humans. The cGAS–STING priming data (PMID: 33916318) imply plausible interaction between the genetic lesion and microbial/LPS exposure, but this remains hypothetical.

3. Phenotypes

The phenotype is congenital/neonatal-onset, severe, progressive, and multisystem. Frequencies are qualitative given the ultra-rare cohort (fewer than ~10 reported patients).

Phenotype HPO term Type Onset Severity Notes
Severe anemia HP:0001903 Lab/clinical Neonatal/antenatal Severe Core feature; from failed erythroblast DNA clearance
Thrombocytopenia HP:0001873 Lab Neonatal Moderate–severe Part of pancytopenia
Pancytopenia HP:0001876 Lab Neonatal Severe Severe spectrum
Hemophagocytosis / HLH-like HP:0012156 Lab/clinical Neonatal Severe With hyperferritinemia (PMID 42491852)
Hepatosplenomegaly HP:0001433 Clinical sign Neonatal Moderate–severe
Hepatic fibrosis HP:0001395 Pathology Infancy Progressive
Cholestatic liver disease HP:0002611 Lab/clinical Neonatal Variable
Membranoproliferative glomerulonephritis HP:0000793 Pathology Childhood Progressive With proteinuria (HP:0000093)
Deforming arthropathy HP:0003040 Clinical sign Childhood Progressive, deforming TNF-driven branch
Recurrent fever HP:0001954 / HP:0001945 Symptom Early Episodic Autoinflammatory
Chilblains / vasculitic skin lesions HP:0009710 Physical Early Variable Interferonopathy skin signature
Granuloma HP:0032252 Pathology Variable —
Intestinal inflammation / chronic diarrhea HP:4000055 / HP:0002028 Clinical Early Variable
Failure to thrive / growth delay HP:0001508 / HP:0001510 Clinical Infancy Variable
Motor delay HP:0001270 / HP:0002194 Neurodevelopmental Infancy Variable
Lipodystrophy HP:0009125 Physical Variable — Shared with other interferonopathies
Type 1 diabetes HP:0100651 Lab/clinical Variable —
Severe EBV infection HP:0031693 Clinical Variable —
Subcortical white-matter lesions (imaging) Imaging Variable — Per OMIM description
Increased anti-DNA antibodies — Lab Childhood — Lupus-like autoimmunity

Quality-of-life impact: Given congenital onset, severe anemia/pancytopenia, progressive organ fibrosis, and deforming arthropathy, affected children have substantial functional impairment and dependence on transfusion and immunomodulation. No disease-specific EQ-5D/SF-36/PROMIS data exist for this ultra-rare condition.

4. Genetic/Molecular Information

Causal gene: DNASE2 (DNase II-alpha), HGNC:2960, Entrez 1777, Ensembl ENSG00000105612, UniProt O00115, locus 19p13.13; phenotype OMIM #619858.

Pathogenic variants. Biallelic loss-of-function variants cause disease. Reported types include missense variants abolishing endonuclease activity (index families, PMID: 29259162), a novel DNASE2 mutation in a severe antenatal case (PMID: 42491852), and a proximal intronic splice-site variant in two unrelated patients (PMID: 41472683). Under ACMG/AMP criteria, disease-causing alleles are classified pathogenic/likely pathogenic when they ablate DNase II enzymatic activity. Functional consequence: loss of function (reduced/absent acid DNase II activity). Origin is germline; no somatic/cancer association. Population allele frequencies for pathogenic alleles are extremely low (ultra-rare), consistent with gnomAD LoF tolerance for carriers (F008).

Modifier genes. No human modifiers confirmed. In mice, the pathway genes Ifnar1, Sting1 (Tmem173), Irf3, and Irf7 act as powerful genetic modifiers of outcome (anemia vs arthritis vs rescue; F003/F005).

Epigenetics / chromosomal abnormalities. Not implicated; the disease is a single-gene disorder with no reported large-scale structural or epigenetic lesions.

5. Environmental Information

No environmental toxins, radiation, lifestyle factors, or infectious agents are established as causes. The disease is monogenic. The only mechanistically plausible environmental modulator is microbial/LPS stimulation amplifying IFN in cGAS–STING-primed cells (PMID: 33916318) — potentially relevant to flares but unproven clinically. Severe EBV infection (HP:0031693) appears in the HPO spectrum, which may reflect secondary infection susceptibility rather than a trigger.

6. Mechanism / Pathophysiology

Ordered causal chain (initiating lesion → clinical manifestation):

  1. Biallelic loss-of-function DNASE2 variants result in absent/severely reduced lysosomal acid DNase II activity (F001, F006).
  2. Loss of DNase II leads to failure to degrade DNA delivered to macrophage lysosomes — specifically the nuclei expelled by erythroblasts during definitive erythropoiesis and DNA from engulfed apoptotic cells (F004).
  3. Undegraded self-DNA accumulates in macrophage lysosomes and leaks into the cytosol (inferred from priming data; F003).
  4. Cytosolic self-DNA activates the TLR-independent cGAS–STING–TBK1 sensing pathway (F003; TLR-independence demonstrated, PMID: 16301743).
  5. Branch A (IRF3/7-dependent): TBK1 activates IRF3/IRF7 → transcription of IFN-β → autocrine/paracrine IFNAR signaling → JAK–STAT1/STAT3 phosphorylation → interferon-stimulated gene program. In the embryo this causes lethal anemia; rescued by IFNAR loss (F003, F005).
  6. Branch B (IRF3/7-independent): the same DNA induces TNF-α (and HMGB-1) independent of IRF3/7 and type I IFN → chronic deforming polyarthritis; prevented by anti-TNF, and in Ifnar-null mice driven further by IFN-γ–producing Th1 cells (F005; PMID: 17066036, PMID: 18991290, PMID: 31464028).
  7. Sustained IFN/TNF/IFN-γ signaling produces the human multisystem disease: anemia/pancytopenia, HLH-like macrophage activation, liver fibrosis, membranoproliferative glomerulonephritis, vasculitic skin disease, GI inflammation, and anti-DNA autoimmunity (F002, F010).
  8. A STING-dependent side-branch contributes to paradoxical ectopic bone formation at sites of DNA accrual (F003; PMID: 27740718).
 DNASE2 LoF (lysosome)
│ no DNA degradation
▼
 Undegraded self-DNA in macrophages  ── UBERON: fetal liver, bone marrow
│ cytosolic leak
▼
 cGAS ─► STING ─► TBK1   (TLR-independent)
│                         │
   IRF3/7 dependent          IRF3/7 independent
│                         │
      IFN-β ─► IFNAR          TNF-α / HMGB-1 ─► (Th1/IFN-γ)
│ JAK-STAT1/3             │
   ANEMIA, IFN signature      CHRONIC ARTHRITIS
   (rescued by Ifnar-/-)      (blocked by anti-TNF)

Molecular pathways: cGAS–STING cytosolic DNA sensing; type I IFN / JAK–STAT; TNF-α signaling (KEGG/Reactome: "Cytosolic DNA-sensing pathway," "Interferon alpha/beta signaling").

Cellular processes: apoptotic DNA fragmentation (GO:0006309), apoptotic cell clearance (GO:0043277), definitive erythropoiesis, macrophage-mediated phagocytosis, chronic inflammation, autoinflammation.

Protein dysfunction: loss of deoxyribonuclease II activity (GO:0004531); the catalytic endonuclease fails to cleave dsDNA to 3′-phosphate products.

Immune system involvement: combined innate autoinflammation (IFN-β, TNF-α) and adaptive autoimmunity (anti-DNA antibodies, Th1/IFN-γ, anti-CCP/RF in the murine model).

Cell types (CL): macrophage (CL:0000235), erythroblast/erythroid precursor (CL:0000765), monocyte (CL:0000576), T-helper 1 cell (CL:0000545).

Subcellular compartment (GO CC): lysosome (GO:0005764); cytosol (site of cGAS sensing); extracellular exosome (GO:0070062).

Molecular profiling: patient RNA-Seq shows an enhanced interferon signature; blood IFN signatures (6-gene ISG panels) are measurable by RT-qPCR/Nanostring PMID: 30413290; proteomic ISG signatures (IFIT5, ISG15, OAS2) are detectable even in neonatal dried blood spots PMID: 40319946.

7. Anatomical Structures Affected

  • Primary organs/systems: hematopoietic system and bone marrow/fetal liver (UBERON:0002371 / UBERON:0002107) — site of erythropoiesis and the primary lesion; liver (UBERON:0002107) — fibrosis/cholestasis; kidney (UBERON:0002113) — membranoproliferative glomerulonephritis; joints/synovium (UBERON:0002217) — deforming arthropathy; skin (UBERON:0002097) — vasculitis/chilblains.
  • Secondary involvement: spleen (hepatosplenomegaly), gastrointestinal tract (intestinal inflammation), heart (cardiomyopathy in severe antenatal case), CNS white matter (subcortical lesions), endocrine pancreas (type 1 diabetes).
  • Body systems: hematologic/immune, hepatobiliary, renal/urinary, musculoskeletal, integumentary, digestive, cardiovascular, nervous, endocrine.
  • Tissue/cell level: macrophages (central nurse macrophages of erythroblastic islands), erythroid precursors, monocytes, synovial cells, glomerular cells; connective tissue (fibrosis).
  • Subcellular: lysosome (primary), cytosol, nucleus (source of self-DNA).
  • Lateralization: systemic/bilateral (e.g., polyarthritis is symmetric).

8. Temporal Development

  • Onset: congenital (HP:0003577) to neonatal (HP:0003623); the most severe cases present antenatally with hydrops and IUGR (PMID: 42491852).
  • Onset pattern: acute/severe in neonates; chronic-progressive thereafter.
  • Progression: progressive multisystem disease with accumulating organ fibrosis (liver, kidney) and deforming, destructive arthropathy; episodic fevers/flares superimposed.
  • Duration: chronic, lifelong without disease-modifying therapy.
  • Critical period: the perinatal/early-infancy window is the key period of vulnerability and the opportune time for intervention (early JAK-inhibitor initiation is associated with better outcomes in interferonopathies, PMID: 41871482).

9. Inheritance and Population

  • Inheritance: autosomal recessive (HP:0000007); biallelic LoF required.
  • Penetrance: appears complete in biallelic LoF individuals (all reported cases affected); expressivity is variable (antenatal-lethal to childhood deforming arthropathy).
  • Carrier status: heterozygotes are healthy; DNASE2 LoF tolerance in gnomAD supports this (F008).
  • Epidemiology: ultra-rare — fewer than ~10 patients reported worldwide across a handful of families; no reliable prevalence/incidence estimates. No dedicated Orphanet prevalence class.
  • Consanguinity/founder effects: consanguinity elevates risk (reported in isolated-population cases); no established founder allele.
  • Sex ratio: no sex bias expected or reported (autosomal recessive).
  • Geographic distribution: cases reported from Europe and the Middle East (e.g., Oman); no endemic clustering beyond consanguineous pedigrees.

10. Diagnostics

  • Laboratory: CBC (severe anemia, cytopenias, erythroblastosis), ferritin (markedly elevated in HLH-like disease), liver enzymes/bilirubin (cholestasis), urinalysis (proteinuria), autoantibodies (anti-DNA, and in the mouse model anti-CCP/RF/MMP-3).
  • Functional enzyme assay: reduced/absent DNase II endonuclease activity is a specific confirmatory test (PMID: 29259162).
  • Biomarker — interferon signature: the blood IFN signature (6-gene ISG panel by RT-qPCR or Nanostring) is the gold-standard screen for type I interferonopathies PMID: 30413290; IFN-alpha protein can be quantified by digital ELISA; constitutive p-STAT1/p-STAT3 in lymphocytes/monocytes supports the diagnosis. Neonatal dried-blood-spot proteomics (IFIT5, ISG15, OAS2) can reveal a subclinical/presymptomatic signature PMID: 40319946.
  • Imaging: brain MRI (subcortical white-matter lesions); abdominal imaging (hepatosplenomegaly, fibrosis); joint imaging (erosive arthropathy); echocardiography (cardiomyopathy in severe cases).
  • Histopathology: liver fibrosis; membranoproliferative glomerulonephritis on renal biopsy; bone marrow with erythroid changes/hemophagocytosis.
  • Genetic testing: WES or WGS is the definitive diagnostic approach (PMID: 42491852: "Whole-exome sequencing enables definitive diagnosis"); targeted single-gene DNASE2 testing or an interferonopathy/autoinflammatory gene panel can confirm biallelic variants. CMA/karyotype/FISH/mtDNA/repeat testing are not indicated (single-gene point/splice variants).
  • Differential diagnosis: other type I interferonopathies — Aicardi–Goutières syndrome (TREX1, RNASEH2A/B/C, SAMHD1, ADAR, IFIH1), SAVI (TMEM173/STING1), ISG15 deficiency, USP18 deficiency, COPA syndrome — plus congenital infections (TORCH), neonatal lupus, HLH, and congenital dyserythropoietic anemias. DNase II deficiency is distinguished by the combination of severe neonatal anemia + glomerulonephritis + liver fibrosis + arthropathy with reduced DNase II activity and biallelic DNASE2 variants.
  • Screening: cascade carrier testing of relatives once a familial variant is known; the IFN/DBS signature could in principle support newborn screening but is not standard.

11. Outcome/Prognosis

  • Survival/mortality: severe; the antenatal end of the spectrum carries high perinatal mortality (hydrops, cardiomyopathy, HLH-like disease) PMID: 42491852. The complete murine knockout is embryonic-lethal, underscoring the severity of total loss of function.
  • Morbidity: high — transfusion-dependent anemia, progressive liver and renal disease, and destructive deforming arthropathy cause major disability.
  • Complications: HLH/macrophage activation, end-organ fibrosis, renal failure risk, joint destruction, growth failure, infection susceptibility.
  • Prognostic factors: severity of residual DNase II activity, age/timing of onset (antenatal = worst), and timeliness of IFN-targeted therapy. No validated prognostic biomarkers specific to this disease beyond the IFN signature as an activity marker.
  • Recovery: without disease-modifying therapy the course is chronic-progressive; JAK inhibition and (conceptually) HSCT may substantially alter outcome.

12. Treatment

  • Pharmacotherapy — JAK inhibitors (primary targeted therapy; NCIT "Janus Kinase Inhibitor"): baricitinib and ruxolitinib (JAK1/2) reduce the IFN signature and immunologic/dermatologic inflammation across interferonopathies (PMID: 41871482); JAK inhibitors are explicitly highlighted as targeted therapy in DNASE2 deficiency (PMID: 42491852). Tofacitinib (JAK1/3) has benefited skin lesions in related interferonopathy (PMID: 40176112). Monitoring for viral reactivation/infection is required.
  • Anti-TNF therapy (NCIT "TNF Inhibitor"): strong preclinical rationale for the arthritis branch — anti-TNF-α antibody prevented polyarthritis in the mouse model (PMID: 17066036).
  • Hematopoietic stem cell transplantation (NCIT "Allogeneic Hematopoietic Stem Cell Transplantation"): conceptually curative because the critical DNase II function is in macrophages/hematopoietic cells; allo-HSCT cured the related interferonopathy SAVI (PMID: 42137281).
  • Supportive care: red-cell transfusions, management of liver/renal disease, treatment of HLH-like flares, nutrition/growth support.
  • Experimental/future: STING or cGAS inhibitors and IFNAR-targeting biologics are mechanistically rational but not yet used for this disease. Gene/enzyme-replacement approaches are theoretical.
  • Pharmacogenomics: none specific; JAK-inhibitor dosing follows interferonopathy experience.

13. Prevention

  • Primary prevention: not possible for a monogenic disease; genetic counseling and reproductive options (carrier testing, prenatal diagnosis, preimplantation genetic testing) are the mainstays for at-risk/consanguineous families.
  • Secondary prevention: early recognition via the blood/DBS interferon signature and prompt genetic diagnosis enable early JAK-inhibitor initiation, which is associated with better outcomes (PMID: 41871482); neonatal DBS proteomics may detect presymptomatic disease (PMID: 40319946).
  • Tertiary prevention: disease-modifying immunomodulation to prevent organ fibrosis and joint destruction; infection surveillance during immunosuppression.
  • Immunization/public-health/environmental measures: not applicable (non-infectious, non-environmental).

14. Other Species / Natural Disease

  • Mouse ortholog: Dnase2a (Entrez 13423, MGI:1329019), NCBI Taxon 10090 (Mus musculus). The mechanism is evolutionarily conserved: macrophage DNase II is required for definitive erythropoiesis and for preventing DNA-driven IFN/TNF autoinflammation (F003–F005).
  • Natural disease in other species: no well-documented naturally occurring DNASE2-deficiency disease in companion animals or wildlife is recorded in the reviewed literature; the knowledge base is dominated by engineered mouse models.
  • Comparative biology: the murine phenotypes (embryonic-lethal anemia; chronic polyarthritis on Ifnar-null background) recapitulate the human hematologic and articular features, making the mouse an excellent comparative model.
  • Zoonotic potential: none (genetic disease).

15. Model Organisms

  • Primary model: the mouse (Mus musculus, Taxon 10090), Dnase2a (MGI:1329019).
  • Genetic models available:
  • Dnase2⁻/⁻ constitutive knockout — embryonic-lethal severe anemia from macrophage-accumulated DNA and IFN-β (PMID: 15568025, PMID: 11375492).
  • Dnase2⁻/⁻ Ifnar⁻/⁻ double knockout — rescued from anemia, develops chronic RA-like polyarthritis (PMID: 17066036).
  • Dnase2⁻/⁻ Irf3⁻/⁻ Irf7⁻/⁻ triple knockout — no anemia, still TNF-α and arthritis, dissecting the two branches (PMID: 18991290).
  • Inducible/conditional Dnase2 deletion — adult-onset arthritis (PMID: 17066036).
  • Triple Sting/Dnase2/Ifnar knockout — demonstrates STING's role in ectopic bone (PMID: 27740718).
  • Cellular models: DNase2-deficient patient fibroblasts with a constitutively primed cGAS–STING–TBK1 pathway (PMID: 33916318); patient lymphocytes/monocytes showing constitutive p-STAT1/3 (PMID: 29259162).
  • Phenotype recapitulation: excellent for the hematologic (anemia) and articular (arthritis) components and for the IFN/TNF mechanism. Limitations: the complete knockout's embryonic lethality requires genetic rescue (IFNAR loss) to study post-natal disease, which alters the IFN axis; some human features (glomerulonephritis, liver fibrosis, neurologic lesions) are less completely modeled.
  • Resources: MGI (Dnase2a, MGI:1329019); Alliance of Genome Resources.

Mechanistic Model / Interpretation

The pathophysiology of DNASE2 deficiency is one of the most cleanly resolved causal chains among the interferonopathies, because mouse genetics have epistatically ordered every step. The single initiating lesion — loss of lysosomal DNase II — removes the terminal nuclease that macrophages use to digest two major streams of self-DNA: the nuclei that erythroblasts expel during definitive erythropoiesis, and the chromatin of apoptotic cells they engulf. The undigested DNA becomes a danger signal. Because sensing is demonstrably TLR-independent and because it is abolished by removing STING-pathway components, the responsible sensor is cytosolic cGAS feeding STING–TBK1. From TBK1 the signal bifurcates: an IRF3/7-dependent arm makes IFN-β (producing the lethal fetal anemia and the human IFN signature), and an IRF3/7-independent arm makes TNF-α (and HMGB-1), producing the chronic deforming arthritis. A third, IFN-independent adaptive arm (IFN-γ–producing Th1 cells) amplifies the arthritis once type I IFN is removed.

This branched architecture directly rationalizes therapy. JAK inhibitors intercept the IFNAR→JAK–STAT limb and should dampen the IFN-driven systemic and hematologic/skin disease; anti-TNF should specifically address the arthritis limb; and HSCT, by replacing the macrophage compartment with DNase II-competent cells, addresses the lesion at its cellular source. The gnomAD constraint data close the loop on genetics: DNASE2 tolerates heterozygous loss of function, exactly as required for a recessive disease whose carriers are healthy.

Mechanistic step Position Key evidence Source
DNASE2 LoF → no lysosomal DNA digestion Upstream (initiating) 29259162, 9446563 human
Macrophage accumulation of erythroid/apoptotic DNA Upstream 11375492 mouse
TLR-independent cytosolic sensing (cGAS-STING-TBK1) Midstream 16301743, 33916318 mouse, in vitro
IRF3/7 → IFN-β → IFNAR → anemia Downstream (branch A) 15568025, 18991290 mouse
IRF3/7-independent TNF-α → arthritis Downstream (branch B) 17066036, 18991290 mouse
IFN-γ/Th1 amplification of arthritis Downstream 31464028 mouse
Human multisystem disease Terminal 29259162, 42491852 human

Evidence Base

PMID Role Contribution
29259162 Defining human study Biallelic DNASE2 LoF; IFN signature; core phenotype (F001, F002)
41472683 Human case series Intronic splice variant; confirms recessive LoF; lysosomal role (F001)
42491852 Human case report Severe antenatal spectrum; WES diagnosis; JAK inhibitors (F002, F007)
11375492 Mouse DNase II macrophage non-cell-autonomous role in erythropoiesis (F004)
15568025 Mouse genetics IFN-β/IFNAR causally required for lethal anemia (F003)
16301743 Mouse genetics TLR-independent self-DNA sensing → cGAS-STING (F003)
33916318 Patient cells Constitutively primed cGAS-STING-TBK1 in DNase2-deficient fibroblasts (F003)
17066036 Mouse TNF-α drives arthritis; anti-TNF protective (F005, F007)
18991290 Mouse genetics IRF3/7-dependent (anemia) vs independent (TNF/arthritis) branches (F005)
31464028 Mouse IFN-γ/Th1 drives type I IFN-independent arthritis (F003)
27740718 Mouse STING required for ectopic bone formation (F003)
20533288 Mouse HMGB-1 pathogenic in the arthritis model; blockade ameliorates
9446563 Molecular DNASE2 cloning; 360-aa protein; chr 19; ubiquitous expression (F006)
30413290 Diagnostic 6-gene IFN signature (RT-qPCR/Nanostring) for interferonopathies
40319946 Diagnostic Neonatal DBS proteomic IFN signature (IFIT5, ISG15, OAS2)
41871482 Treatment JAK1/2 inhibitor efficacy in interferonopathies (F007)
42137281 Treatment Allo-HSCT cured SAVI — rationale for HSCT (F007)
40176112 Treatment Tofacitinib for interferonopathy skin lesions

Limitations and Knowledge Gaps

  • Ultra-rare N: Fewer than ~10 human patients are reported; frequencies, penetrance, and genotype–phenotype correlations are qualitative, not statistical.
  • Human mechanism partly inferred: The cytosolic leak of DNA and the precise cGAS–STING engagement in patients is supported by fibroblast priming data and by mouse genetics, but the full in-vivo human chain is inferred rather than directly demonstrated.
  • No validated human therapy trials: JAK-inhibitor and anti-TNF evidence is extrapolated from related interferonopathies and the mouse model; no DNASE2-specific controlled trials exist. HSCT is conceptual for this disease (demonstrated only in SAVI).
  • Model caveats: The complete Dnase2 knockout is embryonic-lethal, so post-natal mechanisms are studied on genetically altered (IFNAR-null) backgrounds that themselves perturb the IFN axis; renal, hepatic, and neurologic features are less well modeled.
  • Epidemiology/prognosis: No prevalence, survival, or QoL data specific to AIPCS; no Orphanet prevalence class; no natural-history cohort.
  • Identifiers: Orphanet/ICD/MeSH do not yet carry a dedicated code for this ultra-rare entity.

Proposed Follow-up Experiments / Actions

  1. Establish an international AIPCS patient registry to aggregate genotype, phenotype, IFN-signature, treatment response, and survival data across the few families worldwide.
  2. Prospective JAK-inhibitor outcome study (baricitinib/ruxolitinib) in confirmed DNASE2-deficiency patients, tracking IFN signature, transfusion requirement, hepatic/renal function, and arthropathy, with early vs late initiation comparison.
  3. Formal genotype–function correlation: quantify residual DNase II activity for each reported variant (including the intronic splice allele) and relate to clinical severity along the antenatal-lethal → childhood-arthropathy spectrum.
  4. Direct in-patient cGAS–STING engagement assays (e.g., cGAMP measurement, STING oligomerization) to confirm the inferred cytosolic-leak step in humans.
  5. Evaluate upstream pathway inhibitors (cGAS or STING antagonists) in patient cells and Dnase2-null models as alternatives/adjuncts to JAK inhibition.
  6. Pilot/registry data on HSCT for severe, refractory DNASE2 deficiency, given the macrophage-restricted critical function and the SAVI precedent.
  7. Validate neonatal DBS IFN-proteomic screening prospectively in at-risk (consanguineous) pregnancies for presymptomatic detection and early intervention.

Report compiled from 10 confirmed findings and 22 reviewed papers across 5 investigation iterations. Evidence types are distinguished throughout as human clinical, model organism (mouse), in vitro (patient cells), or computational (gnomAD/ontology).

Artifacts

Term Validation

Checked with linkml-term-validator 0.4.5, through the ols: adapter.

Outcome Count
Terms checked 46
Resolved 42
Unresolved (possible confabulation) 0
Obsolete 0
Unverifiable 4
Terms whose name was checked 26
Terms named correctly 17
Terms named as a different term 2
Terms whose name is worth a second look 7

Terms the report names something else

These identifiers resolve, so nothing about them looks wrong, and the ontology calls them something unrelated to what the report calls them. That usually means the identifier is not the one the sentence needs:

  • MONDO:0800132 (6 mentions) - the report calls it "if available", "autoinflammatory-pancytopenia syndrome due to DNASE2 deficiency"; MONDO calls it autoinflammatory-pancytopenia syndrome due to DNASE2 deficiency
  • UBERON:0002217 (1 mention) - the report calls it "joints/synovium"; UBERON calls it synovial joint

Terms whose name is worth a second look

The report's name for these is recognisably related to the term's own name without being one of them. A loose paraphrase reads the same way as a citation of the wrong sibling term - and so does a related synonym, which the ontology records precisely because it names something adjacent rather than the same thing - so these are listed rather than judged:

  • GO:0004531 (2 mentions) - the report calls it "deoxyribonuclease II activity, molecular function"; GO calls it deoxyribonuclease II activity
  • HP:0001903 (2 mentions) - the report calls it "Severe anemia"; HP calls it Anemia
  • HP:0012156 (2 mentions) - the report calls it "Hemophagocytosis / HLH-like"; HP calls it Hemophagocytosis
  • HP:0003040 (2 mentions) - the report calls it "Deforming arthropathy"; HP calls it Arthropathy
  • HP:0009710 (2 mentions) - the report calls it "Chilblains / vasculitic skin lesions"; HP calls it Chilblains, and lists "Chilblain lesions" among its other names
  • HP:0031693 (3 mentions) - the report calls it "Severe EBV infection"; HP calls it Severe Epstein Barr virus infection, and lists "Severe EBV infection" among its other names
  • UBERON:0002097 (1 mention) - the report calls it "skin"; UBERON calls it skin of body, and lists "skin" among its other names

Terms named inconsistently

The report gives these identifiers more than one name of its own:

  • MONDO:0800132 - called "if available", "autoinflammatory-pancytopenia syndrome due to DNASE2 deficiency"

Prefixes with no resolver

Terms carrying these prefixes were not checked either way, because no configured ontology covers them. An unrecognised prefix may name an ontology this run could not reach as easily as one that does not exist, so nothing here is evidence of fabrication: MGI, OMIM, UMLS.

Reference Validation

Checked with linkml-reference-validator 0.3.0.

Outcome Count
References checked 18
Resolved 18
Unresolved (possible confabulation) 0
Unverifiable 0
References weighed for topical relevance 18
On topic 13
Off topic 0

All extracted references resolved successfully.