Warburg-Cinotti Syndrome

Mendelian MONDO:0032579 Pathograph 11 Show in embeddings browser Hereditary connective tissue disorder RTK gain-of-function disorder

Warburg-Cinotti syndrome (WCS; OMIM 618175) is an ultra-rare autosomal dominant connective tissue disorder caused by activating missense variants in DDR2, the collagen-binding receptor tyrosine kinase that regulates connective-tissue formation. It was defined in 2018 in six affected individuals from four families, and by 2024 the literature still described only about six cases worldwide. The clinical picture is progressive and simultaneously proliferative and destructive: corneal neovascularisation and pannus, keloid plaques, chronic skin ulcers, wasting of subcutaneous tissue, flexion contractures of the fingers, and acro-osteolysis. The mechanism is unusually well resolved for a disease this rare, and it is worth stating precisely because the resolution came in two steps seven years apart. In 2018 the founding report observed increased DDR2 phosphorylation in patient fibroblasts and inferred reduced receptor autoinhibition with ligand-independent kinase activation - and, notably, found no evidence for activation of other growth-regulatory signalling pathways, so the lesion was narrow rather than a general growth-signalling excess. In 2025 the enzymology confirmed it and went further: both disease variants autophosphorylate constitutively without ligand, and unphosphorylated DDR2-Y740C has catalytic rates matching fully phosphorylated wild-type protein. That is not a partial release of a brake, it is the fully active conformation reached without any activating input. Tyrosine-740 sits in the activation loop and forms autoinhibitory hydrogen bonds with catalytic residues; a cysteine cannot form them. This is therefore a disease in which the qualitative claim - the kinase is outside its normal regulatory constraints - is directly measured rather than inferred, which is why the pathophysiology node carries `modifier: GAIN_OF_FUNCTION` rather than `INCREASED`.

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1
Inheritance
6
Pathophys.
13
Phenotypes
1
Hypotheses
2
Gaps
11
Pathograph
1
Genes
2
Variants
1
Medical Actions
6
References
1
Deep Research
🏷

Classifications

Harrison's Part
GENETICS ENVIRONMENT DISEASE DERMATOLOGY
👪

Inheritance

1
Autosomal dominant HP:0000006
Heterozygous activating variants, arising both de novo and by transmission. In the founding series three of four families comprised singleton adults with no parental samples available, while in the fourth a variant proven de novo in the mother was transmitted to two of her children - so the same allele is documented arising de novo and then segregating dominantly.
Autosomal dominant inheritance
Show evidence (1 reference)
PMID:30449416 SUPPORT Human Clinical
"In the fourth family, a mother and two of her children were affected, and the c.2219A>G missense variant was proven to be de novo in the mother."
Documents both the de novo origin and the subsequent dominant transmission of the same variant.
◈

Mechanistic Hypotheses

1
A single constitutively active collagen receptor produces both the proliferative and the destructive lesions
ddr2_constitutive_kinase EMERGING
The claim is that keloids and corneal pannus on one hand, and ulcers, subcutaneous wasting and acro-osteolysis on the other, are not two diseases running in parallel but two faces of unregulated matrix turnover driven from one node. Support is the narrowness of the original signalling finding - increased DDR2 phosphorylation with no evidence for activation of other growth-regulatory pathways - which argues against a general growth-signalling excess and for a matrix-specific one. It predicts that inhibiting DDR2 kinase activity should attenuate both arms together.
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Discussions and Knowledge Gaps

2
Is the neonatal p.Asn144Ser variant a Warburg-Cinotti allele at all, given that it lies outside the kinase domain and the reported functional result is a failure of pathway activation rather than a gain?
KNOWLEDGE GAP OPEN wcs_n144s_mechanism_discordance
Attached to
pathophysiology#Activating DDR2 Kinase-Domain Missense Variants pathophysiology#Ligand-Independent Constitutive DDR2 Kinase Activation
Every mechanistically characterised WCS allele is a kinase-domain missense variant producing ligand-independent constitutive activation. A 2025 neonatal case reports a maternally inherited DDR2 c.431A>G (p.Asn144Ser) variant - in the discoidin region, not the kinase domain - and in vitro the mutated DDR2 fails to activate the p38 MAPK pathway. A failure to activate is not obviously the same lesion as constitutive activation, and the reporting authors themselves hedge ("may contribute", "may expand the phenotypic spectrum"). Three readings are open: the allele is mechanistically distinct and expands the spectrum; the p38 readout is not the relevant output for this allele; or the variant is not causal. This entry curates the kinase-domain gain-of-function mechanism and records the discordance here rather than flattening the two into one node.
Show evidence (2 references)
PMID:41778429 REFUTE In Vitro
"In-vitro experiments showed that the mutated DDR2 fails to activate the p38 MAPK pathway."
Recorded as REFUTE against the claim that every reported WCS allele acts by constitutive kinase activation. The result is a loss of pathway activation, which is the opposite direction from the characterised kinase-domain alleles.
PMID:41778429 SUPPORT Human Clinical
"WES revealed a maternally inherited heterozygous missense mutation in DDR2 (c.431A>G, p.Asn144Ser)."
Documents the variant and its position outside the kinase domain, which is what makes the mechanistic question live.
Does pharmacological DDR2 kinase inhibition, shown to abolish variant autophosphorylation in patient fibroblasts, alter the clinical course of Warburg-Cinotti syndrome?
KNOWLEDGE GAP OPEN wcs_dasatinib_translational_gap
Attached to
treatments#DDR2 Kinase Inhibition (Dasatinib) pathophysiology#Ligand-Independent Constitutive DDR2 Kinase Activation
The founding report showed dasatinib prevents DDR2 autophosphorylation in patient fibroblasts and proposed it as an approach to treatment. Seven years on, no patient outcome data exist. The gap is worth stating because the mechanistic case here is unusually clean - a constitutively active kinase with an available inhibitor - and cleanliness of rationale is exactly what makes an untested therapy get cited as though it were a treatment. A relevant design question is also open: the ocular disease is described as accelerated by trauma and surgery, so the peri-operative window may be the natural place to test an inhibitor, rather than continuous therapy.
Show evidence (1 reference)
PMID:30449416 SUPPORT In Vitro
"Finally, we found that the protein kinase inhibitor dasatinib prevented DDR2 autophosphorylation in fibroblasts, suggesting an approach to treatment."
The ex vivo result, and the authors' own framing of it as a suggested approach rather than a demonstrated therapy.
⚙

Pathophysiology

6
Activating DDR2 Kinase-Domain Missense Variants
Two recurrent variants account for the founding series - c.1829T>C (p.Leu610Pro) and c.2219A>G (p.Tyr740Cys) - both in the kinase domain. The structural basis is specific: Tyr-740 lies in the activation loop and forms autoinhibitory hydrogen bonds with key catalytic residues, and a cysteine substituted at that position cannot form them, releasing the A-loop from its autoinhibitory conformation.
DDR2 hgnc:2731 HUGO Gene Nomenclature Committee (hgnc) Relation: this pathophysiological event involves this gene This pathophysiological event involves DDR2 (hgnc:2731), qualified as gain of function. hgnc:2731 is a gene from the HUGO Gene Nomenclature Committee. ⇑ GAIN OF FUNCTION
Genetic context allele_type: SNV variant_origin: GERMLINE zygosity: HETEROZYGOUS functional_impact_category: GAIN_OF_FUNCTION
Heterozygous germline missense variants in the DDR2 kinase domain, recurrent across unrelated families and arising both de novo and by dominant transmission. p.Tyr740Cys substitutes an activation-loop tyrosine whose autoinhibitory hydrogen bonds cannot form with cysteine.
Downstream
Ligand-Independent Constitutive DDR2 Kinase Activation Loss of the autoinhibitory clamp permits activation without collagen.
Show evidence (2 references)
PMID:30449416 SUPPORT Human Clinical
"In six affected individuals from four families, we found one of two recurrent variants in discoidin domain receptor tyrosine kinase 2 (DDR2): c.1829T>C (p.Leu610Pro) or c.2219A>G (p.Tyr740Cys)."
Establishes the causal gene and the two recurrent disease alleles.
PMID:41259339 SUPPORT In Vitro
"Tyrosine-740 is a residue in the A-loop of DDR2 kinase that forms autoinhibitory hydrogen bonds with key catalytic residues. These hydrogen bonds cannot form in the cysteine-substituted variant, providing a structural explanation for the release of the A-loop from its autoinhibitory conformation."
Gives the residue-level structural mechanism by which this specific substitution disables autoinhibition.
Ligand-Independent Constitutive DDR2 Kinase Activation
The central node, and the claim is stronger than "more active". Both disease variants autophosphorylate constitutively when expressed as full-length proteins in mammalian cells, without ligand. Kinetically, unphosphorylated DDR2-Y740C has autophosphorylation and substrate phosphorylation rates similar to those of fully phosphorylated wild-type DDR2 - meaning the variant bypasses all autoinhibitory constraints and adopts the fully active kinase conformation - while ATP binding affinity is unchanged, so the gain is in catalysis and regulation rather than in substrate handling. Because the kinase is operating outside its normal regulatory constraints rather than merely running above its normal level, this node is tagged GAIN_OF_FUNCTION rather than INCREASED.
cell surface receptor protein tyrosine kinase signaling pathway GO:0007169 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves cell surface receptor protein tyrosine kinase signaling pathway (GO:0007169), qualified as gain of function. GO:0007169 is a biological process from the Gene Ontology. ⇑ GAIN OF FUNCTION
DDR2 protein tyrosine kinase activity GO:0004713 Gene Ontology (GO) Relation: this pathophysiological event involves this molecular function This pathophysiological event involves DDR2 protein tyrosine kinase activity, annotated with protein tyrosine kinase activity (GO:0004713), qualified as gain of function. GO:0004713 is a molecular function from the Gene Ontology. ⇑ GAIN OF FUNCTION
Downstream
Dysregulated Fibroblast ECM Remodeling Sustained DDR2 signalling in fibroblasts drives the matrix-remodelling program.
Show evidence (3 references)
PMID:41259339 SUPPORT In Vitro
"Here we show that both disease variants exhibit ligand-independent constitutive autophosphorylation when expressed as full-length proteins in mammalian cells."
Demonstrates constitutive, ligand-independent activation for both disease variants - the defining molecular event.
PMID:41259339 SUPPORT In Vitro
"The increased catalytic rates of unphosphorylated DDR2-Y740C kinase were similar to those of fully phosphorylated WT DDR2, indicating that the missense variant bypasses all autoinhibitory constraints and adopts the fully active kinase conformation."
The quantitative result behind the qualitative GAIN_OF_FUNCTION call: the unphosphorylated variant already behaves like the fully activated wild-type enzyme.
PMID:30449416 SUPPORT In Vitro
"Phosphorylation of DDR2 was increased in fibroblasts from affected individuals, suggesting reduced receptor autoinhibition and ligand-independent kinase activation."
The original observation in patient-derived fibroblasts that the 2025 enzymology later confirmed and quantified.
Dysregulated Fibroblast ECM Remodeling
The fibroblast is the effector cell, and the output is a matrix program running without its normal input. DDR2's physiological role is to sense collagen and regulate connective-tissue formation, so a receptor locked on produces continuous remodelling signalling in a tissue that is not remodelling. This single node accounts for the clinically paradoxical combination of proliferative lesions (keloids, corneal pannus) and destructive ones (ulcers, subcutaneous wasting, acro-osteolysis): both are outputs of unregulated matrix turnover, not of two separate processes.
fibroblast CL:0000057 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves fibroblast (CL:0000057). CL:0000057 is a cell type from the Cell Ontology.
extracellular matrix disassembly GO:0022617 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased extracellular matrix disassembly (GO:0022617). GO:0022617 is a biological process from the Gene Ontology. ↑ INCREASED collagen catabolic process GO:0030574 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased collagen catabolic process (GO:0030574). GO:0030574 is a biological process from the Gene Ontology. ↑ INCREASED
Downstream
Progressive Corneal Neovascularization and Pannus Ocular surface manifestation of unregulated matrix remodelling.
Fibroproliferative and Ulcerative Skin Disease Cutaneous manifestation, both proliferative and destructive.
Acro-osteolysis and Flexion Contractures Skeletal and periarticular manifestation.
Show evidence (2 references)
PMID:30449416 SUPPORT Human Clinical
"DDR2 encodes a collagen-responsive receptor tyrosine kinase that regulates connective-tissue formation."
Establishes the normal function whose constitutive activation produces a connective-tissue phenotype.
PMID:41259339 SUPPORT INDIRECT Other
"Warburg-Cinotti syndrome is a severe connective tissue disorder, characterised by a range of manifestations including joint contractures of the hand, corneal vascularisation and pannus, skin fusion and infection, keloid plaques and acro-osteolysis."
Lists the connective-tissue manifestations that constitute the clinical output of this node. Graded OTHER and INDIRECT because this is disease-background prose in an in vitro enzymology paper, not a clinical observation the paper made.
Progressive Corneal Neovascularization and Pannus
The most characteristic feature and the one that drives ophthalmic morbidity. Reported as progressive, and clinically important is its behaviour around intervention: in a 2024 paediatric case the vascularized mass arose after trauma, invaded the cornea, and recurred larger after each surgical intervention until it covered the whole cornea.
cornea UBERON:0000964 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in cornea (UBERON:0000964). UBERON:0000964 is an anatomical location from the Uberon multi-species anatomy ontology.
Show evidence (2 references)
PMID:30449416 SUPPORT Human Clinical
"We have investigated a distinct disorder with progressive corneal neovascularization, keloid formation, chronic skin ulcers, wasting of subcutaneous tissue, flexion contractures of the fingers, and acro-osteolysis."
Establishes progressive corneal neovascularisation as a defining feature of the disorder.
PMID:39095787 SUPPORT Human Clinical
"The mass enlarged and gradually invaded the cornea. With each surgical intervention, the mass recurred and grew even larger rapidly. The patient ended up with the mass covering the entire cornea along with symblepharon formation."
The paediatric case this node's description refers to: progressive corneal invasion accelerated by each surgical intervention, ending in total corneal coverage with symblepharon.
Fibroproliferative and Ulcerative Skin Disease
Both directions at once, in the same skin. Keloid-like polymorphic plaques and hyperkeratotic and verrucoid lesions on the proliferative side; chronic ulceration, cicatricial alopecia and pseudosyndactyly of the toes on the destructive side. Documented as progressive in an adult.
skin of body UBERON:0002097 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in skin of body (UBERON:0002097). UBERON:0002097 is an anatomical location from the Uberon multi-species anatomy ontology.
Show evidence (2 references)
PMID:35036505 SUPPORT Human Clinical
"The skin can be affected by chronic ulcerations, pseudosyndactyly of the toes, hyperkeratotic and verrucoid lesions, cicatricial alopecia, and spontaneous polymorphic plaques having features similar to keloids."
Enumerates the cutaneous manifestations, spanning both proliferative and destructive lesion types.
PMID:35036505 SUPPORT Human Clinical
"This report demonstrates the progressive nature of skin lesions in an adult with WCS."
Establishes that the cutaneous disease progresses rather than stabilising in adulthood.
Acro-osteolysis and Flexion Contractures
Resorption of distal bone with progressive flexion contractures of the fingers. This is the clearest expression of the destructive arm of the mechanism: bone is being removed, not failing to form.
Show evidence (1 reference)
PMID:30449416 SUPPORT Human Clinical
"We have investigated a distinct disorder with progressive corneal neovascularization, keloid formation, chronic skin ulcers, wasting of subcutaneous tissue, flexion contractures of the fingers, and acro-osteolysis."
Establishes acro-osteolysis and finger flexion contractures as defining features.
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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 Warburg-Cinotti Syndrome 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

13
Ear 1
Conductive Hearing Impairment HP:0000405 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Conductive deafness, annotated with Conductive hearing impairment (HP:0000405). HP:0000405 is a phenotype from the Human Phenotype Ontology.
Show evidence (3 references)
PMID:41778429 SUPPORT INDIRECT Other
"The first reported case involved a male patient presenting with a range of symptoms, including corneal pannus, conductive hearing loss, hand joint flexion conjectures, phalangeal osteolytic defects, joint lesions, significant fat loss in the hands, feet, and face, oligospermia, spontaneous..."
Specifies the hearing loss of the index WCS patient as conductive, which is what fixes the binding at HP:0000405 rather than the general parent. Graded OTHER and INDIRECT because the sentence summarises a previously published case in this paper's literature review rather than reporting this paper's own patient.
PMID:41259339 SUPPORT INDIRECT Other
"Warburg-Cinotti syndrome is a rare connective tissue disease characterised by pathological features that include blepharophimosis, progressive corneal vascularisation, deafness, acro-osteolysis, excessive contractures, and keloid-like plaques"
Lists deafness among the defining features. Graded OTHER and INDIRECT as disease-background prose rather than a clinical observation of this paper, and INDIRECT also because it names deafness without specifying the conductive mechanism this node asserts.
PMID:39095787 SUPPORT INDIRECT Human Clinical
"Warburg et al. first described a 42-year-old white male with deafness, acro-osteolysis, wasting of subcutaneous tissue, and corneal vascularization secondary to ocular surface surgery in 2006"
Records deafness in the original patient description of the syndrome. INDIRECT for this node because it does not distinguish conductive from sensorineural.
Integument 3
Keloid Formation Keloids HP:0010562 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Keloids (HP:0010562). HP:0010562 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:30449416 SUPPORT Human Clinical
"We have investigated a distinct disorder with progressive corneal neovascularization, keloid formation, chronic skin ulcers, wasting of subcutaneous tissue, flexion contractures of the fingers, and acro-osteolysis."
Reports keloid formation as a defining feature.
PMID:35036505 SUPPORT Human Clinical
"spontaneous polymorphic plaques having features similar to keloids"
Characterises the lesions as spontaneous and keloid-like rather than classical post-traumatic keloids.
Chronic Skin Ulceration HP:0200042 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Chronic skin ulceration, annotated with Skin ulcer (HP:0200042), qualified as temporality chronic. HP:0200042 is a phenotype from the Human Phenotype Ontology.
Temporal: CHRONIC
Show evidence (1 reference)
PMID:35036505 SUPPORT Human Clinical
"The skin can be affected by chronic ulcerations, pseudosyndactyly of the toes, hyperkeratotic and verrucoid lesions, cicatricial alopecia, and spontaneous polymorphic plaques having features similar to keloids."
Reports chronic ulceration among the cutaneous manifestations.
Thin Skin HP:0000963 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Thin skin (HP:0000963), qualified as neonatal onset. HP:0000963 is a phenotype from the Human Phenotype Ontology.
Onset: NEONATAL
Show evidence (1 reference)
PMID:41778429 SUPPORT DIRECT Human Clinical
"our case presented symptoms during the neonatal period. Notably, the infant experienced respiratory distress due to upper airway obstruction linked to nasal deformities, along with a short neck and thin skin"
Direct observation of thin skin in this paper's own neonatal patient.
Musculoskeletal 2
Acro-osteolysis HP:0002797 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Acro-osteolysis, annotated with Osteolysis (HP:0002797), qualified as course progressive. HP:0002797 is a phenotype from the Human Phenotype Ontology.
Course: PROGRESSIVE
Show evidence (1 reference)
PMID:41259339 SUPPORT INDIRECT Other
"Warburg-Cinotti syndrome is a severe connective tissue disorder, characterised by a range of manifestations including joint contractures of the hand, corneal vascularisation and pannus, skin fusion and infection, keloid plaques and acro-osteolysis."
Lists acro-osteolysis among the defining manifestations. Graded OTHER and INDIRECT because this is disease-background prose in an in vitro enzymology paper rather than a clinical observation.
Flexion Contractures of the Fingers HP:0001371 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Flexion contracture of finger, annotated with Flexion contracture (HP:0001371), qualified as course progressive. HP:0001371 is a phenotype from the Human Phenotype Ontology.
Course: PROGRESSIVE
Show evidence (1 reference)
PMID:30449416 SUPPORT Human Clinical
"We have investigated a distinct disorder with progressive corneal neovascularization, keloid formation, chronic skin ulcers, wasting of subcutaneous tissue, flexion contractures of the fingers, and acro-osteolysis."
Reports finger flexion contractures as a defining feature.
Respiratory 1
Spontaneous Pneumothorax HP:0002107 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Spontaneous pneumothorax, annotated with Pneumothorax (HP:0002107). HP:0002107 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:41778429 SUPPORT INDIRECT Other
"The first reported case involved a male patient presenting with a range of symptoms, including corneal pannus, conductive hearing loss, hand joint flexion conjectures, phalangeal osteolytic defects, joint lesions, significant fat loss in the hands, feet, and face, oligospermia, spontaneous..."
Records spontaneous pneumothorax in the index WCS patient. Graded OTHER and INDIRECT because the sentence summarises a previously published case in this paper's literature review rather than reporting this paper's own patient.
Other 6
Corneal Neovascularization HP:0011496 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Corneal neovascularization (HP:0011496), qualified as course progressive. HP:0011496 is a phenotype from the Human Phenotype Ontology.
Course: PROGRESSIVE
Show evidence (3 references)
PMID:30449416 SUPPORT Human Clinical
"We have investigated a distinct disorder with progressive corneal neovascularization, keloid formation, chronic skin ulcers, wasting of subcutaneous tissue, flexion contractures of the fingers, and acro-osteolysis."
Reports progressive corneal neovascularisation as a defining feature.
PMID:39095787 SUPPORT Human Clinical
"A seven-year-old boy developed a gelatinous vascularized conjunctiva-like mass secondary to trauma. The mass enlarged and gradually invaded the cornea."
Documents the corneal vascular invasion itself, in a child, and its trauma-provoked onset.
PMID:39095787 SUPPORT Human Clinical
"Considering Warburg-Cinotti syndrome, we should be vigilant of patients exhibiting progressive conjunctival invasion of the cornea, even those without systemic manifestations or a positive family history."
The diagnostic point: progressive conjunctival invasion of the cornea can be the presenting and isolated feature, without systemic signs or a family history.
Wasting of Subcutaneous Tissue Reduced subcutaneous adipose tissue HP:0003758 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Decreased subcutaneous fat, annotated with Reduced subcutaneous adipose tissue (HP:0003758). HP:0003758 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:30449416 SUPPORT Human Clinical
"We have investigated a distinct disorder with progressive corneal neovascularization, keloid formation, chronic skin ulcers, wasting of subcutaneous tissue, flexion contractures of the fingers, and acro-osteolysis."
Reports wasting of subcutaneous tissue as a defining feature.
Blepharophimosis HP:0000581 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Blepharophimosis (HP:0000581). HP:0000581 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:41259339 SUPPORT INDIRECT Other
"Warburg-Cinotti syndrome is a rare connective tissue disease characterised by pathological features that include blepharophimosis, progressive corneal vascularisation, deafness, acro-osteolysis, excessive contractures, and keloid-like plaques"
Lists blepharophimosis among the defining features. Graded OTHER and INDIRECT because the statement is disease-background prose in an in vitro enzymology paper rather than a clinical observation the paper made.
Symblepharon HP:0430007 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Symblepharon (HP:0430007). HP:0430007 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:39095787 SUPPORT Human Clinical
"The patient ended up with the mass covering the entire cornea along with symblepharon formation."
Documents symblepharon formation in the paediatric case.
Multiple Joint Contractures HP:0002828 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Excessive joint contractures, annotated with Multiple joint contractures (HP:0002828). HP:0002828 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:41259339 SUPPORT INDIRECT Other
"Warburg-Cinotti syndrome is a severe connective tissue disorder, characterised by a range of manifestations including joint contractures of the hand, corneal vascularisation and pannus, skin fusion and infection, keloid plaques and acro-osteolysis."
Characterises the contractures as a defining manifestation. Graded OTHER and INDIRECT as disease-background prose in an enzymology paper.
Palatal Abnormalities Abnormal palate morphology HP:0000174 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Palatal abnormalities, annotated with Abnormal palate morphology (HP:0000174). HP:0000174 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:42323896 SUPPORT INDIRECT Other
"since variants in this gene can cause Warburg-Cinotti syndrome, the phenotypic spectrum of which includes palatal abnormalities"
Records palatal abnormalities as part of the WCS spectrum. Graded INDIRECT because the statement appears as background in a study of a different disease rather than as a primary WCS observation.
🧬

Genetic Associations

1
DDR2
Gene: DDR2 hgnc:2731 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is DDR2 (hgnc:2731). hgnc:2731 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: CAUSATIVE variant_origin: GERMLINE
Show evidence (2 references)
PMID:30449416 SUPPORT Human Clinical
"In six affected individuals from four families, we found one of two recurrent variants in discoidin domain receptor tyrosine kinase 2 (DDR2): c.1829T>C (p.Leu610Pro) or c.2219A>G (p.Tyr740Cys)."
Recurrence of two specific variants across four unrelated families is the core human genetic argument.
PMID:41259339 SUPPORT In Vitro
"Compared with WT DDR2, DDR2-Y740C displayed further enhanced autophosphorylation and substrate phosphorylation rates, but no effect on ATP binding affinity."
Quantitative enzymology localising the gain of function to catalysis and regulation rather than to substrate or nucleotide binding.
🔬

Variants

2
DDR2 c.2219A>G (p.Tyr740Cys) Pathogenic
Gene: DDR2 hgnc:2731 HUGO Gene Nomenclature Committee (hgnc) Relation: this variant is in this gene This variant is in DDR2 (hgnc:2731). hgnc:2731 is a gene from the HUGO Gene Nomenclature Committee. SNV
Recurrent activating kinase-domain variant and the best-characterised WCS allele. Tyrosine-740 lies in the activation loop and forms autoinhibitory hydrogen bonds with key catalytic residues that a cysteine cannot form. Kinetically the unphosphorylated variant matches fully phosphorylated wild-type enzyme.
Show evidence (1 reference)
PMID:41259339 SUPPORT In Vitro
"The increased catalytic rates of unphosphorylated DDR2-Y740C kinase were similar to those of fully phosphorylated WT DDR2, indicating that the missense variant bypasses all autoinhibitory constraints and adopts the fully active kinase conformation."
Establishes the magnitude and nature of the gain of function for this specific allele.
DDR2 c.1829T>C (p.Leu610Pro) Pathogenic
Gene: DDR2 hgnc:2731 HUGO Gene Nomenclature Committee (hgnc) Relation: this variant is in this gene This variant is in DDR2 (hgnc:2731). hgnc:2731 is a gene from the HUGO Gene Nomenclature Committee. SNV
The second recurrent activating kinase-domain variant. Shown to autophosphorylate constitutively without ligand, though the detailed enzymology reported to date is for p.Tyr740Cys.
Show evidence (1 reference)
PMID:41259339 SUPPORT In Vitro
"Here we show that both disease variants exhibit ligand-independent constitutive autophosphorylation when expressed as full-length proteins in mammalian cells."
Covers both recurrent variants, establishing constitutive activation for p.Leu610Pro as well as p.Tyr740Cys.
💊

Medical Actions

1
DDR2 Kinase Inhibition (Dasatinib)
Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Agent: dasatinib NCIT:C38713 NCI Thesaurus (NCIT) Relation: this treatment uses this therapeutic agent This treatment uses dasatinib (NCIT:C38713). NCIT:C38713 is a therapeutic agent from the NCI Thesaurus.
Mechanism-directed and preclinical only. Dasatinib prevented DDR2 autophosphorylation in patient fibroblasts, and the founding authors proposed it as an approach to treatment. No patient outcome data have been published in the seven years since. Curated because the rationale is specific and directly targets the disease's central node - and hedged with an attached knowledge gap for the same reason.
Mechanism Target:
Ligand-Independent Constitutive DDR2 Kinase Activation — Directly inhibits the constitutively active kinase that is the causal node of the disease.
Show evidence (1 reference)
PMID:30449416 SUPPORT In Vitro
"Finally, we found that the protein kinase inhibitor dasatinib prevented DDR2 autophosphorylation in fibroblasts, suggesting an approach to treatment."
Shows the inhibitor acting on the specific molecular event this node describes, in patient-derived cells.
Show evidence (1 reference)
PMID:30449416 SUPPORT In Vitro
"Finally, we found that the protein kinase inhibitor dasatinib prevented DDR2 autophosphorylation in fibroblasts, suggesting an approach to treatment."
The entire published evidence base for this treatment, which is why it carries an attached knowledge gap rather than an efficacy claim.
🌍

Environmental Factors

1
Ocular and cutaneous trauma or surgery
exposure to ocular surface surgery or trauma ECTO:2000054 Environmental Conditions, Treatments and Exposures Ontology (ECTO) Relation: this environmental factor is this exposure This environmental factor is exposure to ocular surface surgery or trauma, annotated with exposure to surgery (ECTO:2000054). ECTO:2000054 is an exposure from the Environmental Conditions, Treatments and Exposures Ontology.
The exposure is trauma or surgery, but the binding covers only the surgical half. ECTO was searched for trauma, injury, wound, physical, mechanical, burn, and laceration and returns nothing for any of them, while surgery resolves. Its exposure classes are overwhelmingly chemical, dietary, and infectious, with no physical-injury branch. ECTO:2000054 is therefore the most specific accurate binding available, with the trauma component carried in preferred_term and in the evidence. Revisit if ECTO adds a physical-injury branch.
The single most actionable finding in the clinical literature on this disease, and the one with a management consequence. Lesions are provoked by injury and accelerated by attempts to remove them: the original 2006 patient's corneal vascularization arose after ocular surface surgery, and in the 2024 paediatric case the mass began after trauma and recurred larger after every surgical intervention until it covered the whole cornea. Read against the entry's mechanism, this is what a constitutively active collagen receptor should do. Wounding exposes fibrillar collagen and calls for exactly the matrix-remodelling program that DDR2 normally gates - but the gate is already open, so the response does not terminate.
Show evidence (2 references)
PMID:39095787 SUPPORT Human Clinical
"A seven-year-old boy developed a gelatinous vascularized conjunctiva-like mass secondary to trauma."
Documents trauma as the provoking event for lesion onset.
PMID:39095787 SUPPORT Human Clinical
"Warburg et al. first described a 42-year-old white male with deafness, acro-osteolysis, wasting of subcutaneous tissue, and corneal vascularization secondary to ocular surface surgery in 2006"
The original patient description also attributes the corneal vascularization to preceding ocular surface surgery, so the pattern is not confined to one case.
Mechanism Target:
EXACERBATES Dysregulated Fibroblast ECM Remodeling — Tissue injury supplies the collagen exposure and wound-healing context in which the already-unregulated remodelling program runs, producing lesion onset at the site of injury and rapid regrowth after excision.
Show evidence (1 reference)
PMID:39095787 SUPPORT Human Clinical
"With each surgical intervention, the mass recurred and grew even larger rapidly."
Each surgical attempt made the lesion worse, which is the clearest evidence that intervention accelerates rather than controls the remodelling program.
🔬

Diagnosis

2
Molecular Genetic Testing of DDR2
The diagnosis is molecular. Two recurrent kinase-domain variants account for the founding series, so they are the first things to look for, but novel alleles continue to be reported and not all of them have the same mechanism.
Show evidence (1 reference)
PMID:30449416 SUPPORT Human Clinical
"In six affected individuals from four families, we found one of two recurrent variants in discoidin domain receptor tyrosine kinase 2 (DDR2): c.1829T>C (p.Leu610Pro) or c.2219A>G (p.Tyr740Cys)."
Identifies the two recurrent alleles that molecular testing should prioritise.
DDR2 Autophosphorylation Assay in Patient Fibroblasts
Functional confirmation where a variant of uncertain significance needs adjudicating. Increased DDR2 phosphorylation in patient fibroblasts was the original functional evidence, and the same assay reads out inhibitor response.
Show evidence (1 reference)
PMID:30449416 SUPPORT In Vitro
"Phosphorylation of DDR2 was increased in fibroblasts from affected individuals, suggesting reduced receptor autoinhibition and ligand-independent kinase activation."
The patient-fibroblast assay that established functional consequence.
{ }

Source YAML

click to show 
name: Warburg-Cinotti Syndrome
creation_date: "2026-08-30T19:30:00Z"
category: Mendelian
disease_term:
  preferred_term: Warburg-Cinotti syndrome
  term:
    id: MONDO:0032579
    label: warburg-cinotti syndrome
description: >
  Warburg-Cinotti syndrome (WCS; OMIM 618175) is an ultra-rare autosomal
  dominant connective tissue disorder caused by activating missense variants in
  DDR2, the collagen-binding receptor tyrosine kinase that regulates
  connective-tissue formation. It was defined in 2018 in six affected
  individuals from four families, and by 2024 the literature still described
  only about six cases worldwide. The clinical picture is progressive and
  simultaneously proliferative and destructive: corneal neovascularisation and
  pannus, keloid plaques, chronic skin ulcers, wasting of subcutaneous tissue,
  flexion contractures of the fingers, and acro-osteolysis.

  The mechanism is unusually well resolved for a disease this rare, and it is
  worth stating precisely because the resolution came in two steps seven years
  apart. In 2018 the founding report observed increased DDR2 phosphorylation in
  patient fibroblasts and inferred reduced receptor autoinhibition with
  ligand-independent kinase activation - and, notably, found no evidence for
  activation of other growth-regulatory signalling pathways, so the lesion was
  narrow rather than a general growth-signalling excess. In 2025 the enzymology
  confirmed it and went further: both disease variants autophosphorylate
  constitutively without ligand, and unphosphorylated DDR2-Y740C has catalytic
  rates matching fully phosphorylated wild-type protein. That is not a partial
  release of a brake, it is the fully active conformation reached without any
  activating input. Tyrosine-740 sits in the activation loop and forms
  autoinhibitory hydrogen bonds with catalytic residues; a cysteine cannot form
  them.

  This is therefore a disease in which the qualitative claim - the kinase is
  outside its normal regulatory constraints - is directly measured rather than
  inferred, which is why the pathophysiology node carries
  `modifier: GAIN_OF_FUNCTION` rather than `INCREASED`.

synonyms:
  - WRCN
  - WCS
  - Warburg-Cinotti disease

parents:
  - Hereditary connective tissue disorder
  - RTK gain-of-function disorder

classifications:
  harrisons_chapter:
  - classification_value: GENETICS_ENVIRONMENT_DISEASE
    evidence:
    - reference: PMID:41259339
      reference_title: "Warburg-Cinotti disease variant p.Tyr740Cys enhances catalytic activity of DDR2 kinase."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Missense mutations in the DDR2 kinase domain cause Warburg-Cinotti syndrome in an autosomal dominant manner."
      explanation: >
        A monogenic dominant disorder defined by missense variants in a single
        gene, placing it in Harrison's genetics Part.
  - classification_value: DERMATOLOGY
    evidence:
    - reference: PMID:35036505
      reference_title: "Progression of skin lesions in Warburg-Cinotti syndrome."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "The skin can be affected by chronic ulcerations, pseudosyndactyly of the toes, hyperkeratotic and verrucoid lesions, cicatricial alopecia, and spontaneous polymorphic plaques having features similar to keloids."
      explanation: >
        A substantial and progressive cutaneous burden places this partly in
        Harrison's dermatology Part.

inheritance:
- name: Autosomal dominant
  inheritance_term:
    preferred_term: Autosomal dominant inheritance
    term:
      id: HP:0000006
      label: Autosomal dominant inheritance
  description: >
    Heterozygous activating variants, arising both de novo and by transmission.
    In the founding series three of four families comprised singleton adults
    with no parental samples available, while in the fourth a variant proven de
    novo in the mother was transmitted to two of her children - so the same
    allele is documented arising de novo and then segregating dominantly.
  evidence:
  - reference: PMID:30449416
    reference_title: "Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In the fourth family, a mother and two of her children were affected, and the c.2219A>G missense variant was proven to be de novo in the mother."
    explanation: >
      Documents both the de novo origin and the subsequent dominant
      transmission of the same variant.

notes: >
  Ultra-rare: six individuals from four families at first description, still
  roughly six cases worldwide as of 2024, with individual reports since. No
  frequency values are set anywhere in this entry, and none should be - there
  is no denominator.

  Two entries in the wider DDR2 literature that are NOT curated as evidence
  here, and why:

  A 2026 study identified DDR2 as a candidate risk gene for nonsyndromic cleft
  palate, with zebrafish knockdown producing craniofacial abnormalities. That
  is a different disease and a different allelic mechanism (biallelic
  hypomorphic risk alleles, not dominant activating variants); it is cited once
  below only for the statement that the WCS phenotypic spectrum includes
  palatal abnormalities, not as mechanism evidence for this entry.

  Loss-of-function DDR2 variants are reported to cause a distinct recessive
  skeletal dysplasia, which would make DDR2 a clean gain-of-function /
  loss-of-function pair on one receptor. That contrast is deliberately left out
  of the entry body because none of the references cached for this curation
  states it, and it is not a claim to make from memory. It is a good target for
  a follow-up increment.

pathophysiology:
- name: Activating DDR2 Kinase-Domain Missense Variants
  biological_scale: MOLECULAR
  description: >
    Two recurrent variants account for the founding series - c.1829T>C
    (p.Leu610Pro) and c.2219A>G (p.Tyr740Cys) - both in the kinase domain. The
    structural basis is specific: Tyr-740 lies in the activation loop and forms
    autoinhibitory hydrogen bonds with key catalytic residues, and a cysteine
    substituted at that position cannot form them, releasing the A-loop from
    its autoinhibitory conformation.
  genes:
  - preferred_term: DDR2
    term:
      id: hgnc:2731
      label: DDR2
    modifier: GAIN_OF_FUNCTION
  genetic_context:
    description: >-
      Heterozygous germline missense variants in the DDR2 kinase domain,
      recurrent across unrelated families and arising both de novo and by
      dominant transmission. p.Tyr740Cys substitutes an activation-loop
      tyrosine whose autoinhibitory hydrogen bonds cannot form with cysteine.
    allele_type: SNV
    variant_origin: GERMLINE
    zygosity: HETEROZYGOUS
    functional_impact_category: GAIN_OF_FUNCTION
  evidence:
  - reference: PMID:30449416
    reference_title: "Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In six affected individuals from four families, we found one of two recurrent variants in discoidin domain receptor tyrosine kinase 2 (DDR2): c.1829T>C (p.Leu610Pro) or c.2219A>G (p.Tyr740Cys)."
    explanation: >
      Establishes the causal gene and the two recurrent disease alleles.
  - reference: PMID:41259339
    reference_title: "Warburg-Cinotti disease variant p.Tyr740Cys enhances catalytic activity of DDR2 kinase."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Tyrosine-740 is a residue in the A-loop of DDR2 kinase that forms autoinhibitory hydrogen bonds with key catalytic residues. These hydrogen bonds cannot form in the cysteine-substituted variant, providing a structural explanation for the release of the A-loop from its autoinhibitory conformation."
    explanation: >
      Gives the residue-level structural mechanism by which this specific
      substitution disables autoinhibition.
  downstream:
  - target: Ligand-Independent Constitutive DDR2 Kinase Activation
    description: Loss of the autoinhibitory clamp permits activation without collagen.

- name: Ligand-Independent Constitutive DDR2 Kinase Activation
  biological_scale: MOLECULAR
  description: >
    The central node, and the claim is stronger than "more active". Both
    disease variants autophosphorylate constitutively when expressed as
    full-length proteins in mammalian cells, without ligand. Kinetically,
    unphosphorylated DDR2-Y740C has autophosphorylation and substrate
    phosphorylation rates similar to those of fully phosphorylated wild-type
    DDR2 - meaning the variant bypasses all autoinhibitory constraints and
    adopts the fully active kinase conformation - while ATP binding affinity is
    unchanged, so the gain is in catalysis and regulation rather than in
    substrate handling. Because the kinase is operating outside its normal
    regulatory constraints rather than merely running above its normal level,
    this node is tagged GAIN_OF_FUNCTION rather than INCREASED.
  molecular_functions:
  - preferred_term: DDR2 protein tyrosine kinase activity
    modifier: GAIN_OF_FUNCTION
    term:
      id: GO:0004713
      label: protein tyrosine kinase activity
  biological_processes:
  - preferred_term: cell surface receptor protein tyrosine kinase signaling pathway
    modifier: GAIN_OF_FUNCTION
    term:
      id: GO:0007169
      label: cell surface receptor protein tyrosine kinase signaling pathway
  evidence:
  - reference: PMID:41259339
    reference_title: "Warburg-Cinotti disease variant p.Tyr740Cys enhances catalytic activity of DDR2 kinase."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Here we show that both disease variants exhibit ligand-independent constitutive autophosphorylation when expressed as full-length proteins in mammalian cells."
    explanation: >
      Demonstrates constitutive, ligand-independent activation for both
      disease variants - the defining molecular event.
  - reference: PMID:41259339
    reference_title: "Warburg-Cinotti disease variant p.Tyr740Cys enhances catalytic activity of DDR2 kinase."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "The increased catalytic rates of unphosphorylated DDR2-Y740C kinase were similar to those of fully phosphorylated WT DDR2, indicating that the missense variant bypasses all autoinhibitory constraints and adopts the fully active kinase conformation."
    explanation: >
      The quantitative result behind the qualitative GAIN_OF_FUNCTION call:
      the unphosphorylated variant already behaves like the fully activated
      wild-type enzyme.
  - reference: PMID:30449416
    reference_title: "Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Phosphorylation of DDR2 was increased in fibroblasts from affected individuals, suggesting reduced receptor autoinhibition and ligand-independent kinase activation."
    explanation: >
      The original observation in patient-derived fibroblasts that the 2025
      enzymology later confirmed and quantified.
  downstream:
  - target: Dysregulated Fibroblast ECM Remodeling
    description: >
      Sustained DDR2 signalling in fibroblasts drives the matrix-remodelling
      program.

- name: Dysregulated Fibroblast ECM Remodeling
  biological_scale: CELLULAR
  description: >
    The fibroblast is the effector cell, and the output is a matrix program
    running without its normal input. DDR2's physiological role is to sense
    collagen and regulate connective-tissue formation, so a receptor locked on
    produces continuous remodelling signalling in a tissue that is not
    remodelling. This single node accounts for the clinically paradoxical
    combination of proliferative lesions (keloids, corneal pannus) and
    destructive ones (ulcers, subcutaneous wasting, acro-osteolysis): both are
    outputs of unregulated matrix turnover, not of two separate processes.
  cell_types:
  - preferred_term: fibroblast
    term:
      id: CL:0000057
      label: fibroblast
  biological_processes:
  - preferred_term: extracellular matrix disassembly
    modifier: INCREASED
    term:
      id: GO:0022617
      label: extracellular matrix disassembly
  - preferred_term: collagen catabolic process
    modifier: INCREASED
    term:
      id: GO:0030574
      label: collagen catabolic process
  evidence:
  - reference: PMID:30449416
    reference_title: "Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "DDR2 encodes a collagen-responsive receptor tyrosine kinase that regulates connective-tissue formation."
    explanation: >
      Establishes the normal function whose constitutive activation produces a
      connective-tissue phenotype.
  - reference: PMID:41259339
    reference_title: "Warburg-Cinotti disease variant p.Tyr740Cys enhances catalytic activity of DDR2 kinase."
    supports: SUPPORT
    evidence_source: OTHER
    directness: INDIRECT
    snippet: "Warburg-Cinotti syndrome is a severe connective tissue disorder, characterised by a range of manifestations including joint contractures of the hand, corneal vascularisation and pannus, skin fusion and infection, keloid plaques and acro-osteolysis."
    explanation: >
      Lists the connective-tissue manifestations that constitute the clinical
      output of this node. Graded OTHER and INDIRECT because this is
      disease-background prose in an in vitro enzymology paper, not a clinical
      observation the paper made.
  downstream:
  - target: Progressive Corneal Neovascularization and Pannus
    description: Ocular surface manifestation of unregulated matrix remodelling.
  - target: Fibroproliferative and Ulcerative Skin Disease
    description: Cutaneous manifestation, both proliferative and destructive.
  - target: Acro-osteolysis and Flexion Contractures
    description: Skeletal and periarticular manifestation.

- name: Progressive Corneal Neovascularization and Pannus
  biological_scale: TISSUE
  description: >
    The most characteristic feature and the one that drives ophthalmic
    morbidity. Reported as progressive, and clinically important is its
    behaviour around intervention: in a 2024 paediatric case the vascularized
    mass arose after trauma, invaded the cornea, and recurred larger after each
    surgical intervention until it covered the whole cornea.
  locations:
  - preferred_term: cornea
    term:
      id: UBERON:0000964
      label: cornea
  evidence:
  - reference: PMID:30449416
    reference_title: "Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We have investigated a distinct disorder with progressive corneal neovascularization, keloid formation, chronic skin ulcers, wasting of subcutaneous tissue, flexion contractures of the fingers, and acro-osteolysis."
    explanation: >
      Establishes progressive corneal neovascularisation as a defining feature
      of the disorder.
  - reference: PMID:39095787
    reference_title: "Progressive conjunctival invasion of cornea in a child with Warburg-Cinotti Syndrome: a case report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The mass enlarged and gradually invaded the cornea. With each surgical intervention, the mass recurred and grew even larger rapidly. The patient ended up with the mass covering the entire cornea along with symblepharon formation."
    explanation: >
      The paediatric case this node's description refers to: progressive
      corneal invasion accelerated by each surgical intervention, ending in
      total corneal coverage with symblepharon.

- name: Fibroproliferative and Ulcerative Skin Disease
  biological_scale: TISSUE
  description: >
    Both directions at once, in the same skin. Keloid-like polymorphic plaques
    and hyperkeratotic and verrucoid lesions on the proliferative side; chronic
    ulceration, cicatricial alopecia and pseudosyndactyly of the toes on the
    destructive side. Documented as progressive in an adult.
  locations:
  - preferred_term: skin of body
    term:
      id: UBERON:0002097
      label: skin of body
  evidence:
  - reference: PMID:35036505
    reference_title: "Progression of skin lesions in Warburg-Cinotti syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The skin can be affected by chronic ulcerations, pseudosyndactyly of the toes, hyperkeratotic and verrucoid lesions, cicatricial alopecia, and spontaneous polymorphic plaques having features similar to keloids."
    explanation: >
      Enumerates the cutaneous manifestations, spanning both proliferative and
      destructive lesion types.
  - reference: PMID:35036505
    reference_title: "Progression of skin lesions in Warburg-Cinotti syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This report demonstrates the progressive nature of skin lesions in an adult with WCS."
    explanation: >
      Establishes that the cutaneous disease progresses rather than stabilising
      in adulthood.

- name: Acro-osteolysis and Flexion Contractures
  biological_scale: TISSUE
  description: >
    Resorption of distal bone with progressive flexion contractures of the
    fingers. This is the clearest expression of the destructive arm of the
    mechanism: bone is being removed, not failing to form.
  evidence:
  - reference: PMID:30449416
    reference_title: "Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We have investigated a distinct disorder with progressive corneal neovascularization, keloid formation, chronic skin ulcers, wasting of subcutaneous tissue, flexion contractures of the fingers, and acro-osteolysis."
    explanation: >
      Establishes acro-osteolysis and finger flexion contractures as defining
      features.

mechanistic_hypotheses:
- hypothesis_group_id: ddr2_constitutive_kinase
  hypothesis_label: A single constitutively active collagen receptor produces both the proliferative and the destructive lesions
  status: EMERGING
  description: >
    The claim is that keloids and corneal pannus on one hand, and ulcers,
    subcutaneous wasting and acro-osteolysis on the other, are not two diseases
    running in parallel but two faces of unregulated matrix turnover driven
    from one node. Support is the narrowness of the original signalling
    finding - increased DDR2 phosphorylation with no evidence for activation of
    other growth-regulatory pathways - which argues against a general
    growth-signalling excess and for a matrix-specific one. It predicts that
    inhibiting DDR2 kinase activity should attenuate both arms together.

discussions:
- discussion_id: wcs_n144s_mechanism_discordance
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - pathophysiology#Activating DDR2 Kinase-Domain Missense Variants
  - pathophysiology#Ligand-Independent Constitutive DDR2 Kinase Activation
  prompt: >-
    Is the neonatal p.Asn144Ser variant a Warburg-Cinotti allele at all, given
    that it lies outside the kinase domain and the reported functional result
    is a failure of pathway activation rather than a gain?
  rationale: >-
    Every mechanistically characterised WCS allele is a kinase-domain missense
    variant producing ligand-independent constitutive activation. A 2025
    neonatal case reports a maternally inherited DDR2 c.431A>G (p.Asn144Ser)
    variant - in the discoidin region, not the kinase domain - and in vitro the
    mutated DDR2 fails to activate the p38 MAPK pathway. A failure to activate
    is not obviously the same lesion as constitutive activation, and the
    reporting authors themselves hedge ("may contribute", "may expand the
    phenotypic spectrum"). Three readings are open: the allele is
    mechanistically distinct and expands the spectrum; the p38 readout is not
    the relevant output for this allele; or the variant is not causal. This
    entry curates the kinase-domain gain-of-function mechanism and records the
    discordance here rather than flattening the two into one node.
  evidence:
  - reference: PMID:41778429
    reference_title: "A Novel Mutation in DDR2 Associated with Warburg-Cinotti Syndrome in a Neonate."
    supports: REFUTE
    evidence_source: IN_VITRO
    snippet: "In-vitro experiments showed that the mutated DDR2 fails to activate the p38 MAPK pathway."
    explanation: >-
      Recorded as REFUTE against the claim that every reported WCS allele acts
      by constitutive kinase activation. The result is a loss of pathway
      activation, which is the opposite direction from the characterised
      kinase-domain alleles.
  - reference: PMID:41778429
    reference_title: "A Novel Mutation in DDR2 Associated with Warburg-Cinotti Syndrome in a Neonate."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "WES revealed a maternally inherited heterozygous missense mutation in DDR2 (c.431A>G, p.Asn144Ser)."
    explanation: >-
      Documents the variant and its position outside the kinase domain, which
      is what makes the mechanistic question live.

- discussion_id: wcs_dasatinib_translational_gap
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - treatments#DDR2 Kinase Inhibition (Dasatinib)
  - pathophysiology#Ligand-Independent Constitutive DDR2 Kinase Activation
  prompt: >-
    Does pharmacological DDR2 kinase inhibition, shown to abolish variant
    autophosphorylation in patient fibroblasts, alter the clinical course of
    Warburg-Cinotti syndrome?
  rationale: >-
    The founding report showed dasatinib prevents DDR2 autophosphorylation in
    patient fibroblasts and proposed it as an approach to treatment. Seven
    years on, no patient outcome data exist. The gap is worth stating because
    the mechanistic case here is unusually clean - a constitutively active
    kinase with an available inhibitor - and cleanliness of rationale is
    exactly what makes an untested therapy get cited as though it were a
    treatment. A relevant design question is also open: the ocular disease is
    described as accelerated by trauma and surgery, so the peri-operative
    window may be the natural place to test an inhibitor, rather than
    continuous therapy.
  evidence:
  - reference: PMID:30449416
    reference_title: "Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Finally, we found that the protein kinase inhibitor dasatinib prevented DDR2 autophosphorylation in fibroblasts, suggesting an approach to treatment."
    explanation: >-
      The ex vivo result, and the authors' own framing of it as a suggested
      approach rather than a demonstrated therapy.

phenotypes:
- category: Ophthalmologic
  name: Corneal Neovascularization
  description: >
    Progressive, and the feature most consistently reported across cases.
  phenotype_term:
    preferred_term: Corneal neovascularization
    term:
      id: HP:0011496
      label: Corneal neovascularization
    clinical_course: PROGRESSIVE
  evidence:
  - reference: PMID:30449416
    reference_title: "Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We have investigated a distinct disorder with progressive corneal neovascularization, keloid formation, chronic skin ulcers, wasting of subcutaneous tissue, flexion contractures of the fingers, and acro-osteolysis."
    explanation: >
      Reports progressive corneal neovascularisation as a defining feature.
  - reference: PMID:39095787
    reference_title: "Progressive conjunctival invasion of cornea in a child with Warburg-Cinotti Syndrome: a case report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A seven-year-old boy developed a gelatinous vascularized conjunctiva-like mass secondary to trauma. The mass enlarged and gradually invaded the cornea."
    explanation: >
      Documents the corneal vascular invasion itself, in a child, and its
      trauma-provoked onset.
  - reference: PMID:39095787
    reference_title: "Progressive conjunctival invasion of cornea in a child with Warburg-Cinotti Syndrome: a case report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Considering Warburg-Cinotti syndrome, we should be vigilant of patients exhibiting progressive conjunctival invasion of the cornea, even those without systemic manifestations or a positive family history."
    explanation: >
      The diagnostic point: progressive conjunctival invasion of the cornea can
      be the presenting and isolated feature, without systemic signs or a
      family history.

- category: Dermatologic
  name: Keloid Formation
  description: >
    Spontaneous polymorphic plaques with keloid-like features, arising without
    the antecedent wounding keloids normally require.
  phenotype_term:
    preferred_term: Keloids
    term:
      id: HP:0010562
      label: Keloids
  evidence:
  - reference: PMID:30449416
    reference_title: "Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We have investigated a distinct disorder with progressive corneal neovascularization, keloid formation, chronic skin ulcers, wasting of subcutaneous tissue, flexion contractures of the fingers, and acro-osteolysis."
    explanation: >
      Reports keloid formation as a defining feature.
  - reference: PMID:35036505
    reference_title: "Progression of skin lesions in Warburg-Cinotti syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "spontaneous polymorphic plaques having features similar to keloids"
    explanation: >
      Characterises the lesions as spontaneous and keloid-like rather than
      classical post-traumatic keloids.

- category: Dermatologic
  name: Chronic Skin Ulceration
  description: >
    The destructive counterpart of the keloid phenotype, in the same organ.
  phenotype_term:
    preferred_term: Chronic skin ulceration
    term:
      id: HP:0200042
      label: Skin ulcer
    temporality: CHRONIC
  evidence:
  - reference: PMID:35036505
    reference_title: "Progression of skin lesions in Warburg-Cinotti syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The skin can be affected by chronic ulcerations, pseudosyndactyly of the toes, hyperkeratotic and verrucoid lesions, cicatricial alopecia, and spontaneous polymorphic plaques having features similar to keloids."
    explanation: >
      Reports chronic ulceration among the cutaneous manifestations.

- category: Skeletal
  name: Acro-osteolysis
  description: >
    Resorption of the distal phalangeal bone. HPO has no acro-osteolysis term;
    this is bound to the general Osteolysis term with the specificity carried
    in `preferred_term`, per the ontology term contract.
  phenotype_term:
    preferred_term: Acro-osteolysis
    term:
      id: HP:0002797
      label: Osteolysis
    clinical_course: PROGRESSIVE
  evidence:
  - reference: PMID:41259339
    reference_title: "Warburg-Cinotti disease variant p.Tyr740Cys enhances catalytic activity of DDR2 kinase."
    supports: SUPPORT
    evidence_source: OTHER
    directness: INDIRECT
    snippet: "Warburg-Cinotti syndrome is a severe connective tissue disorder, characterised by a range of manifestations including joint contractures of the hand, corneal vascularisation and pannus, skin fusion and infection, keloid plaques and acro-osteolysis."
    explanation: >
      Lists acro-osteolysis among the defining manifestations. Graded OTHER and
      INDIRECT because this is disease-background prose in an in vitro
      enzymology paper rather than a clinical observation.

- category: Musculoskeletal
  name: Flexion Contractures of the Fingers
  description: >
    Progressive contractures of the hand, reported alongside contractures at
    other joints.
  phenotype_term:
    preferred_term: Flexion contracture of finger
    term:
      id: HP:0001371
      label: Flexion contracture
    clinical_course: PROGRESSIVE
  evidence:
  - reference: PMID:30449416
    reference_title: "Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We have investigated a distinct disorder with progressive corneal neovascularization, keloid formation, chronic skin ulcers, wasting of subcutaneous tissue, flexion contractures of the fingers, and acro-osteolysis."
    explanation: >
      Reports finger flexion contractures as a defining feature.

- category: Dermatologic
  name: Wasting of Subcutaneous Tissue
  description: >
    Loss of subcutaneous tissue, part of the destructive arm and a contributor
    to the progeroid appearance the disorder can present with.
  phenotype_term:
    preferred_term: Decreased subcutaneous fat
    term:
      id: HP:0003758
      label: Reduced subcutaneous adipose tissue
  evidence:
  - reference: PMID:30449416
    reference_title: "Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We have investigated a distinct disorder with progressive corneal neovascularization, keloid formation, chronic skin ulcers, wasting of subcutaneous tissue, flexion contractures of the fingers, and acro-osteolysis."
    explanation: >
      Reports wasting of subcutaneous tissue as a defining feature.

- category: Ophthalmologic
  name: Blepharophimosis
  description: >
    Named among the defining features of the syndrome. Recorded because it is
    part of the periocular phenotype that accompanies the corneal disease.
  phenotype_term:
    preferred_term: Blepharophimosis
    term:
      id: HP:0000581
      label: Blepharophimosis
  evidence:
  - reference: PMID:41259339
    reference_title: "Warburg-Cinotti disease variant p.Tyr740Cys enhances catalytic activity of DDR2 kinase."
    supports: SUPPORT
    evidence_source: OTHER
    directness: INDIRECT
    snippet: "Warburg-Cinotti syndrome is a rare connective tissue disease characterised by pathological features that include blepharophimosis, progressive corneal vascularisation, deafness, acro-osteolysis, excessive contractures, and keloid-like plaques"
    explanation: >
      Lists blepharophimosis among the defining features. Graded OTHER and
      INDIRECT because the statement is disease-background prose in an in vitro
      enzymology paper rather than a clinical observation the paper made.

- category: Ophthalmologic
  name: Symblepharon
  description: >
    Adhesion between the palpebral and bulbar conjunctiva. In the reported
    paediatric case it accompanied the mass that had grown to cover the entire
    cornea, and it is part of what makes the ocular surface disease
    architecturally destructive rather than only vascular.
  phenotype_term:
    preferred_term: Symblepharon
    term:
      id: HP:0430007
      label: Symblepharon
  evidence:
  - reference: PMID:39095787
    reference_title: "Progressive conjunctival invasion of cornea in a child with Warburg-Cinotti Syndrome: a case report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The patient ended up with the mass covering the entire cornea along with symblepharon formation."
    explanation: >
      Documents symblepharon formation in the paediatric case.

- category: Otologic
  name: Conductive Hearing Impairment
  description: >
    Deafness was present in the original 2006 patient description that gave the
    syndrome half its name, and is named among the defining features. The
    review of that original case specifies it as conductive, which is
    consistent with the middle-ear and ear-cartilage involvement reported
    across the series, so the phenotype is bound at the conductive level rather
    than at the general hearing-impairment parent.
  phenotype_term:
    preferred_term: Conductive deafness
    term:
      id: HP:0000405
      label: Conductive hearing impairment
  evidence:
  - reference: PMID:41778429
    reference_title: "A Novel Mutation in DDR2 Associated with Warburg-Cinotti Syndrome in a Neonate."
    supports: SUPPORT
    evidence_source: OTHER
    directness: INDIRECT
    snippet: "The first reported case involved a male patient presenting with a range of symptoms, including corneal pannus, conductive hearing loss, hand joint flexion conjectures, phalangeal osteolytic defects, joint lesions, significant fat loss in the hands, feet, and face, oligospermia, spontaneous pneumothorax, and facial dysmorphism."
    explanation: >
      Specifies the hearing loss of the index WCS patient as conductive, which
      is what fixes the binding at HP:0000405 rather than the general parent.
      Graded OTHER and INDIRECT because the sentence summarises a previously
      published case in this paper's literature review rather than reporting
      this paper's own patient.
  - reference: PMID:41259339
    reference_title: "Warburg-Cinotti disease variant p.Tyr740Cys enhances catalytic activity of DDR2 kinase."
    supports: SUPPORT
    evidence_source: OTHER
    directness: INDIRECT
    snippet: "Warburg-Cinotti syndrome is a rare connective tissue disease characterised by pathological features that include blepharophimosis, progressive corneal vascularisation, deafness, acro-osteolysis, excessive contractures, and keloid-like plaques"
    explanation: >
      Lists deafness among the defining features. Graded OTHER and INDIRECT as
      disease-background prose rather than a clinical observation of this
      paper, and INDIRECT also because it names deafness without specifying the
      conductive mechanism this node asserts.
  - reference: PMID:39095787
    reference_title: "Progressive conjunctival invasion of cornea in a child with Warburg-Cinotti Syndrome: a case report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    directness: INDIRECT
    snippet: "Warburg et al. first described a 42-year-old white male with deafness, acro-osteolysis, wasting of subcutaneous tissue, and corneal vascularization secondary to ocular surface surgery in 2006"
    explanation: >
      Records deafness in the original patient description of the syndrome.
      INDIRECT for this node because it does not distinguish conductive from
      sensorineural.

- category: Musculoskeletal
  name: Multiple Joint Contractures
  description: >
    Contractures extend beyond the fingers. The founding series describes
    flexion contractures of the fingers specifically; the broader
    characterisation is "excessive contractures" and "joint contractures of the
    hand", so this is recorded alongside the finger-specific phenotype rather
    than replacing it.
  phenotype_term:
    preferred_term: Excessive joint contractures
    term:
      id: HP:0002828
      label: Multiple joint contractures
  evidence:
  - reference: PMID:41259339
    reference_title: "Warburg-Cinotti disease variant p.Tyr740Cys enhances catalytic activity of DDR2 kinase."
    supports: SUPPORT
    evidence_source: OTHER
    directness: INDIRECT
    snippet: "Warburg-Cinotti syndrome is a severe connective tissue disorder, characterised by a range of manifestations including joint contractures of the hand, corneal vascularisation and pannus, skin fusion and infection, keloid plaques and acro-osteolysis."
    explanation: >
      Characterises the contractures as a defining manifestation. Graded OTHER
      and INDIRECT as disease-background prose in an enzymology paper.

- category: Craniofacial
  name: Palatal Abnormalities
  description: >
    Part of the reported phenotypic spectrum. Recorded at low confidence: the
    citation is a study of nonsyndromic cleft palate that references the WCS
    spectrum in passing, not a WCS case series characterising the palate. Bound
    at the general abnormal-palate level because the source says "palatal
    abnormalities" without specifying.
  phenotype_term:
    preferred_term: Palatal abnormalities
    term:
      id: HP:0000174
      label: Abnormal palate morphology
  evidence:
  - reference: PMID:42323896
    reference_title: "Evidence that disruption of Discoidin domain receptor 2 contributes to palate malformations through effects on the extracellular matrix."
    supports: SUPPORT
    evidence_source: OTHER
    directness: INDIRECT
    snippet: "since variants in this gene can cause Warburg-Cinotti syndrome, the phenotypic spectrum of which includes palatal abnormalities"
    explanation: >
      Records palatal abnormalities as part of the WCS spectrum. Graded
      INDIRECT because the statement appears as background in a study of a
      different disease rather than as a primary WCS observation.

- category: Respiratory
  name: Spontaneous Pneumothorax
  description: >
    Reported in the index patient and one of the recurring features of the
    published series. It fits the entry's connective-tissue mechanism: an
    unrestrained matrix-remodelling program in a lung whose pleural and septal
    collagen DDR2 normally helps maintain gives a structurally fragile pleura.
  phenotype_term:
    preferred_term: Spontaneous pneumothorax
    term:
      id: HP:0002107
      label: Pneumothorax
  evidence:
  - reference: PMID:41778429
    reference_title: "A Novel Mutation in DDR2 Associated with Warburg-Cinotti Syndrome in a Neonate."
    supports: SUPPORT
    evidence_source: OTHER
    directness: INDIRECT
    snippet: "The first reported case involved a male patient presenting with a range of symptoms, including corneal pannus, conductive hearing loss, hand joint flexion conjectures, phalangeal osteolytic defects, joint lesions, significant fat loss in the hands, feet, and face, oligospermia, spontaneous pneumothorax, and facial dysmorphism."
    explanation: >
      Records spontaneous pneumothorax in the index WCS patient. Graded OTHER
      and INDIRECT because the sentence summarises a previously published case
      in this paper's literature review rather than reporting this paper's own
      patient.

- category: Dermatologic
  name: Thin Skin
  description: >
    Present at birth in the neonatal case, which is the earliest recorded
    dermatologic finding in the syndrome. Distinct from the subcutaneous-tissue
    wasting recorded separately: that is loss of the fat layer beneath the
    dermis, this is the dermis itself.
  phenotype_term:
    preferred_term: Thin skin
    term:
      id: HP:0000963
      label: Thin skin
    onset:
      onset_category: NEONATAL
  evidence:
  - reference: PMID:41778429
    reference_title: "A Novel Mutation in DDR2 Associated with Warburg-Cinotti Syndrome in a Neonate."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    directness: DIRECT
    snippet: "our case presented symptoms during the neonatal period. Notably, the infant experienced respiratory distress due to upper airway obstruction linked to nasal deformities, along with a short neck and thin skin"
    explanation: >
      Direct observation of thin skin in this paper's own neonatal patient.

environmental:
- name: Ocular and cutaneous trauma or surgery
  description: >
    The single most actionable finding in the clinical literature on this
    disease, and the one with a management consequence. Lesions are provoked by
    injury and accelerated by attempts to remove them: the original 2006
    patient's corneal vascularization arose after ocular surface surgery, and
    in the 2024 paediatric case the mass began after trauma and recurred larger
    after every surgical intervention until it covered the whole cornea.

    Read against the entry's mechanism, this is what a constitutively active
    collagen receptor should do. Wounding exposes fibrillar collagen and calls
    for exactly the matrix-remodelling program that DDR2 normally gates - but
    the gate is already open, so the response does not terminate.
  exposure_term:
    preferred_term: exposure to ocular surface surgery or trauma
    term:
      id: ECTO:2000054
      label: exposure to surgery
  notes: >
    The exposure is trauma or surgery, but the binding covers only the surgical
    half. ECTO was searched for trauma, injury, wound, physical, mechanical,
    burn, and laceration and returns nothing for any of them, while surgery
    resolves. Its exposure classes are overwhelmingly chemical, dietary, and
    infectious, with no physical-injury branch. ECTO:2000054 is therefore the
    most specific accurate binding available, with the trauma component carried
    in preferred_term and in the evidence. Revisit if ECTO adds a
    physical-injury branch.
  influences_mechanisms:
  - target: Dysregulated Fibroblast ECM Remodeling
    environmental_effect: EXACERBATES
    causal_link_type: DIRECT
    description: >
      Tissue injury supplies the collagen exposure and wound-healing context in
      which the already-unregulated remodelling program runs, producing lesion
      onset at the site of injury and rapid regrowth after excision.
    evidence:
    - reference: PMID:39095787
      reference_title: "Progressive conjunctival invasion of cornea in a child with Warburg-Cinotti Syndrome: a case report."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "With each surgical intervention, the mass recurred and grew even larger rapidly."
      explanation: >
        Each surgical attempt made the lesion worse, which is the clearest
        evidence that intervention accelerates rather than controls the
        remodelling program.
  evidence:
  - reference: PMID:39095787
    reference_title: "Progressive conjunctival invasion of cornea in a child with Warburg-Cinotti Syndrome: a case report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A seven-year-old boy developed a gelatinous vascularized conjunctiva-like mass secondary to trauma."
    explanation: >
      Documents trauma as the provoking event for lesion onset.
  - reference: PMID:39095787
    reference_title: "Progressive conjunctival invasion of cornea in a child with Warburg-Cinotti Syndrome: a case report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Warburg et al. first described a 42-year-old white male with deafness, acro-osteolysis, wasting of subcutaneous tissue, and corneal vascularization secondary to ocular surface surgery in 2006"
    explanation: >
      The original patient description also attributes the corneal
      vascularization to preceding ocular surface surgery, so the pattern is
      not confined to one case.

genetic:
- name: DDR2
  gene_term:
    preferred_term: DDR2
    term:
      id: hgnc:2731
      label: DDR2
  relationship_type: CAUSATIVE
  variant_origin: GERMLINE
  features: >
    DDR2 encodes a collagen-responsive receptor tyrosine kinase that regulates
    connective-tissue formation. Wild-type DDR2 kinase follows a two-step
    activation mechanism, previously characterised for DDR1, but with enhanced
    autophosphorylation and substrate phosphorylation rates. Disease alleles
    are heterozygous kinase-domain missense variants that disable
    autoinhibition; the recurrent p.Tyr740Cys removes activation-loop hydrogen
    bonds to catalytic residues.
  review_notes: >-
    No ClinGen gene-disease validity assertion exists for DDR2 in Warburg-Cinotti
    syndrome. CAUSATIVE is nonetheless well supported: two recurrent variants
    across four unrelated families, a proven de novo event with subsequent
    dominant transmission, patient-fibroblast functional data, and independent
    enzymology establishing the gain-of-function mechanism at residue level.
    Note that not all reported DDR2 variants fit this mechanism - see the
    discordance recorded for p.Asn144Ser.
  evidence:
  - reference: PMID:30449416
    reference_title: "Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In six affected individuals from four families, we found one of two recurrent variants in discoidin domain receptor tyrosine kinase 2 (DDR2): c.1829T>C (p.Leu610Pro) or c.2219A>G (p.Tyr740Cys)."
    explanation: >
      Recurrence of two specific variants across four unrelated families is
      the core human genetic argument.
  - reference: PMID:41259339
    reference_title: "Warburg-Cinotti disease variant p.Tyr740Cys enhances catalytic activity of DDR2 kinase."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Compared with WT DDR2, DDR2-Y740C displayed further enhanced autophosphorylation and substrate phosphorylation rates, but no effect on ATP binding affinity."
    explanation: >
      Quantitative enzymology localising the gain of function to catalysis and
      regulation rather than to substrate or nucleotide binding.

variants:
- name: DDR2 c.2219A>G (p.Tyr740Cys)
  description: >-
    Recurrent activating kinase-domain variant and the best-characterised WCS
    allele. Tyrosine-740 lies in the activation loop and forms autoinhibitory
    hydrogen bonds with key catalytic residues that a cysteine cannot form.
    Kinetically the unphosphorylated variant matches fully phosphorylated
    wild-type enzyme.
  gene:
    preferred_term: DDR2
    term:
      id: hgnc:2731
      label: DDR2
  type: SNV
  clinical_significance: PATHOGENIC
  evidence:
  - reference: PMID:41259339
    reference_title: "Warburg-Cinotti disease variant p.Tyr740Cys enhances catalytic activity of DDR2 kinase."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "The increased catalytic rates of unphosphorylated DDR2-Y740C kinase were similar to those of fully phosphorylated WT DDR2, indicating that the missense variant bypasses all autoinhibitory constraints and adopts the fully active kinase conformation."
    explanation: >-
      Establishes the magnitude and nature of the gain of function for this
      specific allele.

- name: DDR2 c.1829T>C (p.Leu610Pro)
  description: >-
    The second recurrent activating kinase-domain variant. Shown to
    autophosphorylate constitutively without ligand, though the detailed
    enzymology reported to date is for p.Tyr740Cys.
  gene:
    preferred_term: DDR2
    term:
      id: hgnc:2731
      label: DDR2
  type: SNV
  clinical_significance: PATHOGENIC
  evidence:
  - reference: PMID:41259339
    reference_title: "Warburg-Cinotti disease variant p.Tyr740Cys enhances catalytic activity of DDR2 kinase."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Here we show that both disease variants exhibit ligand-independent constitutive autophosphorylation when expressed as full-length proteins in mammalian cells."
    explanation: >-
      Covers both recurrent variants, establishing constitutive activation for
      p.Leu610Pro as well as p.Tyr740Cys.

diagnosis:
- name: Molecular Genetic Testing of DDR2
  description: >
    The diagnosis is molecular. Two recurrent kinase-domain variants account
    for the founding series, so they are the first things to look for, but
    novel alleles continue to be reported and not all of them have the same
    mechanism.
  evidence:
  - reference: PMID:30449416
    reference_title: "Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In six affected individuals from four families, we found one of two recurrent variants in discoidin domain receptor tyrosine kinase 2 (DDR2): c.1829T>C (p.Leu610Pro) or c.2219A>G (p.Tyr740Cys)."
    explanation: >
      Identifies the two recurrent alleles that molecular testing should
      prioritise.

- name: DDR2 Autophosphorylation Assay in Patient Fibroblasts
  description: >
    Functional confirmation where a variant of uncertain significance needs
    adjudicating. Increased DDR2 phosphorylation in patient fibroblasts was the
    original functional evidence, and the same assay reads out inhibitor
    response.
  evidence:
  - reference: PMID:30449416
    reference_title: "Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Phosphorylation of DDR2 was increased in fibroblasts from affected individuals, suggesting reduced receptor autoinhibition and ligand-independent kinase activation."
    explanation: >
      The patient-fibroblast assay that established functional consequence.

treatments:
- name: DDR2 Kinase Inhibition (Dasatinib)
  description: >
    Mechanism-directed and preclinical only. Dasatinib prevented DDR2
    autophosphorylation in patient fibroblasts, and the founding authors
    proposed it as an approach to treatment. No patient outcome data have been
    published in the seven years since. Curated because the rationale is
    specific and directly targets the disease's central node - and hedged with
    an attached knowledge gap for the same reason.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: dasatinib
      term:
        id: NCIT:C38713
        label: Dasatinib
  target_mechanisms:
  - target: Ligand-Independent Constitutive DDR2 Kinase Activation
    description: >
      Directly inhibits the constitutively active kinase that is the causal
      node of the disease.
    evidence:
    - reference: PMID:30449416
      reference_title: "Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "Finally, we found that the protein kinase inhibitor dasatinib prevented DDR2 autophosphorylation in fibroblasts, suggesting an approach to treatment."
      explanation: >
        Shows the inhibitor acting on the specific molecular event this node
        describes, in patient-derived cells.
  evidence:
  - reference: PMID:30449416
    reference_title: "Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Finally, we found that the protein kinase inhibitor dasatinib prevented DDR2 autophosphorylation in fibroblasts, suggesting an approach to treatment."
    explanation: >
      The entire published evidence base for this treatment, which is why it
      carries an attached knowledge gap rather than an efficacy claim.

references:
- reference: PMID:30449416
  title: "Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome."
- reference: PMID:41259339
  title: "Warburg-Cinotti disease variant p.Tyr740Cys enhances catalytic activity of DDR2 kinase."
- reference: PMID:35036505
  title: "Progression of skin lesions in Warburg-Cinotti syndrome."
- reference: PMID:39095787
  title: "Progressive conjunctival invasion of cornea in a child with Warburg-Cinotti Syndrome: a case report."
- reference: PMID:41778429
  title: "A Novel Mutation in DDR2 Associated with Warburg-Cinotti Syndrome in a Neonate."
- reference: PMID:42323896
  title: "Evidence that disruption of Discoidin domain receptor 2 contributes to palate malformations through effects on the extracellular matrix."
📚

References & Deep Research

References

6
PMID:30449416
Recurrent, Activating Variants in the Receptor Tyrosine Kinase DDR2 Cause Warburg-Cinotti Syndrome.
No top-level findings curated for this source.
PMID:41259339
Warburg-Cinotti disease variant p.Tyr740Cys enhances catalytic activity of DDR2 kinase.
No top-level findings curated for this source.
PMID:35036505
Progression of skin lesions in Warburg-Cinotti syndrome.
No top-level findings curated for this source.
PMID:39095787
Progressive conjunctival invasion of cornea in a child with Warburg-Cinotti Syndrome: a case report.
No top-level findings curated for this source.
PMID:41778429
A Novel Mutation in DDR2 Associated with Warburg-Cinotti Syndrome in a Neonate.
No top-level findings curated for this source.
PMID:42323896
Evidence that disruption of Discoidin domain receptor 2 contributes to palate malformations through effects on the extracellular matrix.
No top-level findings curated for this source.

Deep Research

1
OpenScientist ▸
Warburg-Cinotti Syndrome: Comprehensive Disease Characteristics Report
openscientist-autonomous 16 citations 2026-08-30T19:04:15.714839

Warburg-Cinotti Syndrome: Comprehensive Disease Characteristics Report

Disease Name: Warburg-Cinotti Syndrome (WCS) MONDO ID: MONDO:0032579 OMIM: #618175 Category: Connective Tissue Report compiled: 2026-08-30 (5-iteration autonomous investigation; 11 confirmed findings; 25 papers reviewed)

Summary

Warburg-Cinotti syndrome (WCS; MONDO:0032579; OMIM #618175) is an ultra-rare, autosomal-dominant connective-tissue disorder caused by recurrent activating (gain-of-function) germline missense variants in the collagen receptor tyrosine kinase gene DDR2 (discoidin domain receptor tyrosine kinase 2; OMIM 191311). Only two recurrent hotspot variants have been reported to date — c.1829T>C (p.Leu610Pro) and c.2219A>G (p.Tyr740Cys) — and both render the receptor constitutively autophosphorylated independent of its collagen ligand, bypassing the normal autoinhibitory constraints on kinase activity (PMID: 30449416; PMID: 41259339).

Clinically, WCS is a progressive fibro-proliferative disorder. The classic tetrad comprises progressive corneal neovascularization, keloid formation, chronic skin ulcers with wasting of subcutaneous tissue, finger flexion contractures, and acro-osteolysis (PMID: 30449416). Curated Human Phenotype Ontology annotations (35 features derived from OMIM:618175 via the Monarch Initiative) reveal a much broader, multisystem picture involving craniofacial dysmorphism (narrow nose, long face, posteriorly rotated ears), the ocular surface (corneal neovascularization, symblepharon, limbal stem-cell deficiency), the ear (conductive hearing loss, cholesteatoma), the skin (thin skin, poor wound healing), the skeleton (osteolysis of phalanges, joint contractures), and the respiratory system (pneumothorax). Mechanistically, constitutively active DDR2 in fibroblasts hyperactivates ERK1/2 and NF-κB signaling and drives matrix-metalloproteinase (MMP-1/2/9/13) and MT1-MMP (MMP-14)-mediated extracellular-matrix remodeling, producing the fibrosis, neovascularization, and tissue destruction that characterize the disease (PMID: 28270508; PMID: 25733533).

Because WCS is fundamentally a kinase-activation disease, DDR2-inhibiting tyrosine kinase inhibitors are a mechanistically rational therapeutic strategy. The BCR-ABL inhibitor dasatinib abolishes mutant DDR2 autophosphorylation in patient fibroblasts (PMID: 30449416), and imatinib, nilotinib, and dasatinib are all potent DDR1/DDR2 inhibitors (PMID: 18938156), making them repurposing candidates — although no clinical trial and no gain-of-function animal model of WCS has yet been reported. Notably, DDR2 is allelic to a mechanistically opposite disorder: biallelic loss-of-function DDR2 variants cause the autosomal-recessive skeletal dysplasia SMED-SL (spondylo-meta-epiphyseal dysplasia, short limb–abnormal calcification type; OMIM 271665) (PMID: 24725993; PMID: 36720430).

Section 1 — Disease Information

Overview. Warburg-Cinotti syndrome is a progressive connective-tissue disorder defined by simultaneous fibro-proliferation (keloids, corneal pannus/neovascularization) and tissue destruction (chronic skin ulcers, subcutaneous wasting, acro-osteolysis). It is caused by gain-of-function activation of a collagen-sensing receptor tyrosine kinase, positioning it at the intersection of extracellular-matrix biology and kinase-signaling disease.

Key identifiers (verified via EBI OLS4 MONDO ontology query; Finding F010):

Resource Identifier
MONDO MONDO:0032579
OMIM #618175
UMLS C5193019
MedGen 1677486
GARD 0015007
EFO EFO:0010166
Orphanet No dedicated entry (as of query)
ICD-10 / ICD-11 No specific code identified
MeSH No dedicated descriptor identified

Synonyms / alternative names: Warburg-Cinotti syndrome; abbreviation WRCN (MONDO synonym).

Information source type. Given fewer than ~10 reported individuals worldwide, all information is derived from aggregated disease-level resources (OMIM, MONDO, HPO/Monarch) and individual case reports/case series — not from large EHR or registry datasets. The foundational cohort is 6 affected individuals from 4 families (PMID: 30449416).

Section 2 — Etiology

Primary cause (genetic). WCS is a monogenic, autosomal-dominant disorder caused by heterozygous activating missense variants in DDR2. Two recurrent variants account for all molecularly confirmed classic cases: p.Leu610Pro and p.Tyr740Cys (PMID: 30449416). A novel maternally inherited variant was reported in a neonatal case (PMID: 41778429), indicating the mutational spectrum may be broader than the two original hotspots.

Genetic risk factors. The causal variants are themselves the risk determinant; there are no reported susceptibility loci or modifier genes. Both de novo and inherited transmission are documented — a proven de novo variant arose in a mother who then transmitted it to two children (PMID: 30449416).

Environmental risk factors. No environmental cause is required for disease. However, local trauma appears to provoke and accelerate lesions: a 7-year-old developed a gelatinous vascularized conjunctival mass after ocular trauma that recurrently regrew and invaded the entire cornea despite repeated surgery (PMID: 39095787). This mirrors the keloid biology of WCS, in which the skin overreacts to injury.

Protective factors. None identified (genetic or environmental). Given the trauma-provocation pattern, avoidance of unnecessary trauma/surgery to affected surfaces may be practically protective, though this is inferential.

Gene-environment interaction. The plausible model is that a constitutively active DDR2 receptor lowers the threshold for a pathological wound-healing/ECM-remodeling response, so that ordinary mechanical injury triggers exaggerated, self-perpetuating fibro-proliferation and neovascularization.

Section 3 — Phenotypes

WCS is a multisystem disorder. The classic clinical tetrad/pentad (PMID: 30449416; PMID: 41259339):

  • Progressive corneal neovascularization (HP:0011496) — ocular surface; progressive; trauma-provoked
  • Keloid formation — skin; progressive fibro-proliferation
  • Chronic skin ulcers / poor wound healing (HP:0001058) — skin; chronic
  • Wasting of subcutaneous tissue — skin/subcutis; progressive
  • Flexion contractures of the fingers (HP:0012785) — musculoskeletal; progressive
  • Acro-osteolysis / osteolytic phalangeal defects (HP:0009771) — skeletal; progressive

Curated HPO spectrum with frequencies (Monarch/HPOA, 35 annotations derived from OMIM:618175; Finding F011):

Phenotype HPO term Frequency
Narrow nose HP:0000460 100%
Narrow palpebral fissure HP:0045025 100%
Visual impairment HP:0000505 75%
Joint swelling HP:0001386 67%
Thin skin HP:0000963 67%
Long face HP:0000276 67%
Posteriorly rotated ears HP:0000358 60%
Osteolytic defects of phalanges of hand HP:0009771 60%
Underdeveloped nasal alae HP:0000430 50%
Hypoplasia of ear cartilage HP:0100720 40%
Conductive hearing impairment HP:0000405 40%
High palate HP:0000218 33%
Retinal dystrophy HP:0000556 33%
Pneumothorax HP:0002107 33%
Wrist flexion contracture HP:0001239 33%
Cholesteatoma HP:0009797 20%
Atresia of external auditory canal HP:0000413 20%
Dental crowding / gingival overgrowth / follicular hyperkeratosis / sterile abscess / short chin / ankle & elbow contracture (various) ~17% each
Corneal neovascularization HP:0011496 (annotated, no freq)
Symblepharon HP:0430007 (annotated, no freq)
Limbal stem cell deficiency HP:0032107 (annotated, no freq)
Decreased corneal thickness HP:0100689 (annotated, no freq)
Poor wound healing HP:0001058 (annotated, no freq)
Erythema HP:0010783 (annotated, no freq)
Epicanthus / Blepharophimosis / Low-set ears / Midface retrusion HP:0000286 / HP:0000581 / HP:0000369 / HP:0011800 (annotated, no freq)

Onset, severity, progression. Onset spans childhood to adulthood, with a documented neonatal presentation (respiratory distress from choanal abnormalities) at the earliest extreme (PMID: 41778429; PMID: 39095787). Most core features are progressive, and expressivity is variable even within families.

Quality-of-life impact. No formal EQ-5D/SF-36 data exist. Inferred impact is substantial: progressive corneal opacification/neovascularization threatens vision (visual impairment in 75%), finger contractures and acro-osteolysis impair hand function and dexterity, chronic non-healing ulcers cause pain and infection risk, and conductive hearing loss/cholesteatoma affect hearing.

Section 4 — Genetic / Molecular Information

Causal gene. DDR2 — discoidin domain receptor tyrosine kinase 2; HGNC:2731; NCBI Gene ID 4921; OMIM 191311; chromosome 1q23.3. DDR2 is a non-integrin, collagen-activated receptor tyrosine kinase.

Pathogenic variants (WCS, gain of function):

Variant (cDNA) Protein Type Origin Consequence
c.1829T>C p.Leu610Pro Missense Germline (de novo or inherited, AD) Gain of function — constitutive autophosphorylation
c.2219A>G p.Tyr740Cys Missense Germline (AD) Gain of function — constitutive autophosphorylation
Novel (neonatal) (maternally inherited) Missense Germline Reported; spectrum-expanding (PMID: 41778429)

Classification. The two recurrent variants are pathogenic (recurrent, functionally validated, segregating; consistent with ACMG PS1/PS3/PM1/PP1 lines of evidence). Allele frequency in population databases is effectively absent (private, disease-causing).

Functional consequence — gain of function. Patient fibroblasts show increased DDR2 phosphorylation, indicating reduced autoinhibition and ligand-independent activation (PMID: 30449416). Biochemical work shows both variants exhibit ligand-independent constitutive autophosphorylation as full-length proteins, and the p.Tyr740Cys kinase has enhanced autophosphorylation and substrate-phosphorylation rates with unchanged ATP affinity — the unphosphorylated mutant behaves kinetically like fully phosphorylated wild type, i.e., it bypasses autoinhibitory constraints (PMID: 41259339).

Allelic contrast (loss of function → distinct disorder). Biallelic loss-of-function DDR2 variants (missense, nonsense, deletion, splice; e.g., p.S823Cfs2) cause SMED-SL (spondylo-meta-epiphyseal dysplasia, short limb–abnormal calcification type; OMIM 271665), an autosomal-recessive skeletal dysplasia, via defective intracellular trafficking and loss of collagen-induced activation (PMID: 24725993; PMID: 36720430). This is the opposite functional mechanism* to WCS.

Modifier genes / epigenetics / chromosomal abnormalities. None reported. WCS is not associated with aneuploidy, translocations, or copy-number variants; no epigenetic signature has been described.

Section 5 — Environmental Information

No toxin, radiation, pollution, occupational, infectious, or lifestyle cause is implicated in WCS — it is a monogenic disorder. The one clear environmental modifier is mechanical/surgical trauma, which provokes and accelerates ocular and cutaneous lesions and drives post-surgical recurrence (PMID: 39095787). No infectious agents cause or trigger the disease.

Section 6 — Mechanism / Pathophysiology

Causal chain (upstream → downstream):

Germline activating DDR2 missense variant (p.Leu610Pro / p.Tyr740Cys)
│  (reduced autoinhibition; bypass of autoinhibitory constraints)
▼
Ligand-INDEPENDENT constitutive DDR2 kinase autophosphorylation
│  (does not require collagen binding)
▼
Sustained downstream signaling in fibroblasts: ERK1/2  +  NF-κB
│
▼
Up-regulation of MMPs (MMP-1/2/9/13) and MT1-MMP (MMP-14)
   + DDR2 tethers active MT1-MMP to collagen fibers (sustained ECM degradation)
│
▼
Dysregulated ECM remodeling → fibro-proliferation (keloids, corneal pannus/
neovascularization) AND tissue destruction (ulcers, subcutaneous wasting, acro-osteolysis)
│
▼
Progressive multisystem clinical phenotype

Molecular pathways. DDR2 is a collagen-activated RTK that up-regulates matrix metalloproteinases. In murine melanoma cells, DDR2 drives MMP-2/9 expression through the ERK/NF-κB pathway — DDR2 siRNA suppresses ERK1/2 and NF-κB and down-regulates MMP-2/9 (PMID: 25733533). Relevant GO/pathway terms: transmembrane receptor protein tyrosine kinase signaling (GO:0007169), positive regulation of ERK1/ERK2 cascade (GO:0070374), extracellular matrix disassembly (GO:0022617), collagen catabolic process (GO:0030574).

Cellular processes / effector cell. The fibroblast (CL:0000057) is the central effector cell. In human fibroblasts, DDR2 mediates collagen-induced up-regulation of MT1-MMP and pro-MMP-2 activation (PMID: 28270508). DDR2 also tethers active MT1-MMP to collagen fibers within "DDR2-containing remnants," sustaining pericellular ECM degradation (PMID: 33882324). DDR2 additionally governs fibroblast proliferation as an ECM sensor (PMID: 11375938).

Protein dysfunction. The mutations act by gain of function at the kinase, not by misfolding/aggregation. p.Tyr740Cys increases catalytic activity and removes the autoinhibitory clamp; unphosphorylated mutant behaves like phosphorylated wild type (PMID: 41259339).

Tissue-damage / fibrosis mechanism. DDRs are established anti-fibrotic targets across liver, kidney, lung, cardiovascular, and skin (hypertrophic scar) fibrosis (PMID: 40796038; PMID: 24725424). DDR dysregulation after injury is detrimental and promotes inflammation and fibrosis (PMID: 24361528). In WCS, constitutive DDR2 activity produces a chronic, injury-independent version of this fibrotic program.

Immune involvement. Not a primary autoimmune or immunodeficiency disorder, though NF-κB activation and secondary infection of chronic ulcers/skin fusion contribute to morbidity.

Molecular profiling. No transcriptomic, proteomic, metabolomic, or single-cell datasets specific to WCS patients are available; mechanistic inferences derive from DDR2 fibroblast and cancer-cell models.

Section 7 — Anatomical Structures Affected

Organ / system level:

System Manifestation UBERON (suggested)
Ocular surface Corneal neovascularization, pannus, symblepharon, limbal stem-cell deficiency, thin cornea cornea UBERON:0000964; conjunctiva UBERON:0001811
Skin / integument Keloids, chronic ulcers, thin skin, subcutaneous wasting skin UBERON:0002097; subcutaneous tissue UBERON:0002072
Skeleton (hands) Acro-osteolysis, phalangeal osteolysis, contractures manual digit bone UBERON:0004248; phalanx UBERON:0001449
Joints Flexion contractures (fingers, wrist, elbow, ankle), joint swelling joint UBERON:0000982
Craniofacial Narrow nose, long face, midface retrusion, high palate, short chin face UBERON:0001456; palate UBERON:0001716
Ear Conductive hearing loss, cholesteatoma, EAC atresia, ear-cartilage hypoplasia ear UBERON:0001690; external acoustic meatus UBERON:0001352
Respiratory Pneumothorax; neonatal choanal abnormalities lung UBERON:0002048; choana

Tissue and cell level. Predominantly connective tissue and the corneal/ocular-surface epithelium/stroma. The key targeted cell is the fibroblast (CL:0000057); corneal limbal stem-cell deficiency (HP:0032107) implicates limbal epithelial stem cells.

Subcellular level. Disease originates at the plasma membrane (GO:0005886) receptor; downstream effects converge on the extracellular matrix / extracellular region (GO:0005576) and involve collagen-containing ECM (GO:0062023).

Localization / lateralization. Ocular and cutaneous lesions are typically bilateral but can be asymmetric, with lesion location influenced by sites of trauma.

Section 8 — Temporal Development

  • Onset: Ranges from neonatal (PMID: 41778429) through childhood (PMID: 39095787) to adulthood; onset pattern is generally chronic/insidious and progressive.
  • Progression: Progressive for most features (corneal neovascularization, acro-osteolysis, contractures, skin lesions). Ocular disease can be stepwise/accelerated by trauma and surgery, with rapid regrowth after intervention (PMID: 39095787).
  • Course / duration: Chronic, lifelong. No spontaneous remission is described.
  • Critical periods: Peri-traumatic and peri-surgical windows are periods of vulnerability (lesion provocation/recurrence) and represent the logical window for mechanism-based (kinase-inhibitor) intervention to blunt the fibro-proliferative response.

Section 9 — Inheritance and Population

Epidemiology. WCS is ultra-rare: only 6 affected individuals from 4 families were reported at initial description (PMID: 30449416); by 2024 the literature still described ~6 cases worldwide ("Only six cases have been reported worldwide and our knowledge of this disease remained sparse") (PMID: 39095787), with additional single cases since (PMID: 41778429). No prevalence/incidence figures are calculable; there is no Orphanet epidemiology entry.

Inheritance genetics:

  • Pattern: Autosomal dominant (AD).
  • New vs inherited: Both de novo and inherited — a de novo variant in a mother was transmitted to two children (PMID: 30449416).
  • Penetrance: Appears high in reported carriers, but cohort too small to quantify.
  • Expressivity: Variable, even intrafamilially.
  • Anticipation / mosaicism / founder effects / consanguinity / carrier frequency: No evidence for anticipation; no founder effect (variants are private/recurrent hotspots, not population-restricted); consanguinity is not relevant (dominant, not recessive — in contrast to the allelic recessive SMED-SL). Carrier frequency not applicable for a dominant de-novo-capable disorder.

Demographics. No ethnic predilection, sex bias, or geographic clustering has been established given the tiny case count.

Section 10 — Diagnostics

Genetic testing is definitive. Diagnosis rests on identifying a heterozygous activating DDR2 missense variant (p.Leu610Pro or p.Tyr740Cys, or a novel spectrum variant).

  • WES/WGS: High utility — the original cohort and the neonatal case were solved by whole-exome sequencing (PMID: 30449416; PMID: 41778429).
  • Single-gene / panel testing: Targeted DDR2 sequencing (or a connective-tissue/skeletal-dysplasia panel including DDR2) is appropriate once WCS is suspected clinically.
  • CMA / karyotype / FISH / mtDNA / repeat-expansion testing: Not indicated (no structural, mitochondrial, or repeat-expansion mechanism).

Functional / laboratory confirmation. Patient-derived fibroblasts show increased DDR2 autophosphorylation, which can serve as a functional assay (PMID: 30449416).

Imaging. Hand radiographs demonstrate acro-osteolysis and phalangeal osteolytic defects; ophthalmic examination/slit-lamp documents corneal neovascularization, pannus, symblepharon, and corneal thinning; CT may characterize cholesteatoma/EAC atresia and choanal abnormalities.

Biopsy/pathology. Skin lesions show keloidal fibro-proliferation; ocular masses show vascularized fibrovascular tissue invading the cornea (PMID: 39095787).

Differential diagnosis. Multicentric osteolysis/nodulosis/arthropathy (MONA, MMP2), other acro-osteolysis syndromes (Hajdu-Cheney), scleroderma/fibrosing disorders, and — at the gene level — the allelic recessive SMED-SL (opposite mechanism, skeletal dysplasia phenotype) (PMID: 36720430).

Screening. No population/newborn screening exists or is warranted given rarity. Cascade genetic testing of at-risk relatives in a known family is appropriate.

Section 11 — Outcome / Prognosis

No survival, mortality, or formal QoL data exist for this ultra-rare disorder. The disease is chronic, progressive, and lifelong, with cumulative morbidity from:

  • Vision loss — progressive corneal neovascularization/opacification (visual impairment in 75%), aggravated by recurrence after ocular surgery (PMID: 39095787).
  • Hand disability — flexion contractures and acro-osteolysis.
  • Chronic wounds/infection — non-healing ulcers, skin fusion, sterile/infected abscesses.
  • Hearing loss — conductive impairment, cholesteatoma.
  • Respiratory events — pneumothorax (33%); neonatal respiratory distress from choanal abnormalities.

Prognostic factors are not formally established; degree of DDR2 hyperactivation and trauma burden are plausible drivers of severity. Recovery potential is limited under current supportive-only management, but is the central rationale for mechanism-based therapy.

Section 12 — Treatment

There is no approved, disease-specific therapy; management is currently supportive (wound care, ophthalmic surface management, contracture/hand therapy, hearing rehabilitation, treatment of infection). Surgery on ocular/skin lesions is complicated by trauma-provoked recurrence (PMID: 39095787), so surgical decisions should be cautious.

Mechanism-based (experimental) pharmacotherapy — DDR2 tyrosine-kinase inhibition:

Agent Class Evidence for WCS relevance NCIT (suggested)
Dasatinib BCR-ABL/SRC TKI; potent DDR1/2 inhibitor Prevents mutant DDR2 autophosphorylation in patient fibroblasts (PMID: 30449416); potent DDR inhibitor (PMID: 18938156) NCIT:C38713
Imatinib BCR-ABL TKI Potent DDR1/2 inhibitor (PMID: 18938156) NCIT:C62035
Nilotinib BCR-ABL TKI Potent DDR1/2 inhibitor (PMID: 18938156) NCIT:C48375
WRG-28 Selective allosteric DDR2 inhibitor Attenuates DDR2-driven matrix degradation/MMP13 in osteoarthritis models (PMID: 41955962) — investigational, not yet tested in WCS —

Key supporting quote: "we found that the protein kinase inhibitor dasatinib prevented DDR2 autophosphorylation in fibroblasts, suggesting an approach to treatment" (PMID: 30449416); and "all 3 compounds are potent inhibitors of the kinase activity of both DDR1 and DDR2" (PMID: 18938156).

Personalized-medicine rationale. Because WCS is driven by a single, well-defined activated kinase with no evidence of other growth-pathway activation (PMID: 30449416), it is a strong candidate for genotype-guided kinase-inhibitor therapy. No gene therapy, cell therapy, RNA therapy, or immunotherapy has been reported. No completed or registered clinical trial (NCT) specific to WCS was identified.

Section 13 — Prevention

  • Primary prevention: Not applicable to a de-novo-capable germline disorder. Genetic counseling and cascade/prenatal or preimplantation genetic testing are options for known-variant families.
  • Secondary prevention: Early molecular diagnosis (WES) and early ophthalmic/skin surveillance to intervene before irreversible damage.
  • Tertiary prevention: Minimize provocative trauma/surgery to affected surfaces, aggressive wound-infection control, contracture-preventive physiotherapy, hearing/vision rehabilitation. Mechanism-based TKI therapy — if validated — would be a tertiary-preventive strategy to halt progression.
  • Immunization / public health / environmental interventions: Not applicable.

Section 14 — Other Species / Natural Disease

  • Orthologous gene: DDR2 is conserved. Mouse Ddr2 — NCBI Gene ID 18214 (Mus musculus, NCBI Taxon 10090); zebrafish DDR2 orthologs (Danio rerio, NCBI Taxon 7955).
  • Natural disease: No naturally occurring WCS-equivalent (gain-of-function DDR2) disease has been described in companion animals or wildlife (no OMIA entry identified). Available animal data are engineered loss-of-function models (below), which model DDR2 deficiency, not WCS.
  • Comparative biology: DDR2's role in chondrocyte proliferation, skin wound healing, and craniofacial/palate development is evolutionarily conserved from zebrafish to mouse to human (PMID: 11375938; PMID: 42323896).
  • Transmission / zoonosis: Not applicable (genetic disorder).

Section 15 — Model Organisms

Important caveat: All existing animal models are loss-of-function (Ddr2-null / knockdown), which model the allelic recessive SMED-SL rather than gain-of-function WCS. No gain-of-function (knock-in p.Leu610Pro/p.Tyr740Cys) animal model has yet been reported (Findings F002/F007).

Model Type Phenotype Relevance / limitation
Ddr2-null mouse (Mus musculus, Taxon 10090; Gene 18214) Knockout (LOF) Dwarfism and shortening of long bones from reduced chondrocyte proliferation; reduced proliferative response in skin wound healing; DDR2−/− fibroblasts proliferate more slowly (rescued by WT but not kinase-dead DDR2) (PMID: 11375938) Establishes DDR2 as an ECM-sensing proliferation regulator; models LOF (SMED-SL), not WCS GOF
Zebrafish ddr2 knockdown/knockout (Danio rerio, Taxon 7955) Morphant/KO (LOF) Craniofacial abnormalities resembling human cleft palate (PMID: 42323896) Connects DDR2 to the palatal/craniofacial phenotype seen in WCS
Patient-derived fibroblasts (in vitro) Human primary cells Increased DDR2 autophosphorylation; dasatinib-responsive (PMID: 30449416) Best available WCS-specific functional model and drug-testing platform
Recombinant DDR2 kinase / mammalian expression In vitro / cell-based Constitutive ligand-independent autophosphorylation; enhanced catalysis of Y740C (PMID: 41259339) Defines the biophysical GOF mechanism

Model databases: MGI (mouse Ddr2), ZFIN (zebrafish ddr2), Alliance of Genome Resources.

Supporting quotes: "These mice exhibit dwarfism and shortening of long bones... caused by reduced chondrocyte proliferation" and "In a skin wound healing model, DDR2-/- mice exhibit a reduced proliferative response" (PMID: 11375938); "Knock-down and knock-out of DDR2-orthologs in zebrafish caused craniofacial abnormalities resembling CPO in humans" (PMID: 42323896).

Mechanistic Model / Interpretation

WCS is best understood as a "constitutive kinase" connective-tissue disease. A single-nucleotide germline change removes the autoinhibitory brake on DDR2, so the receptor signals continuously without needing to bind collagen. In fibroblasts — the disease's effector cell — this locks in a chronic ERK/NF-κB → MMP/MT1-MMP program that simultaneously builds abnormal matrix (keloids, corneal pannus and neovascularization) and destroys existing tissue (chronic ulcers, subcutaneous wasting, acro-osteolysis). The apparent paradox of "too much scarring and too much destruction" is resolved by recognizing that both are outputs of dysregulated ECM remodeling driven by the same overactive receptor.

Two natural experiments frame the mechanism:

        DDR2 dosage/activity axis
LOSS of function  ◄──────────────────────────────►  GAIN of function
   SMED-SL (AR)        normal DDR2          Warburg-Cinotti (AD)
 skeletal dysplasia,   collagen-cued        constitutive kinase,
 short limbs,          ECM sensing          fibrosis + osteolysis +
 abnormal calcif.      & wound healing      neovascularization
 (trafficking defect,  (chondrocyte prolif, (ligand-independent
 loss of ligand        wound repair)         autophosphorylation)
 activation)

Both ends of this axis are pathological, and both are informative: the LOF mouse/zebrafish models reveal DDR2's normal developmental roles (chondrocyte proliferation, wound healing, palate formation) — roles that manifest as skeletal/craniofacial overlap features in WCS — while the GOF human disease shows what happens when the same receptor is unleashed.

The therapeutic corollary is unusually clean: turn the kinase off. Dasatinib already abolishes mutant DDR2 autophosphorylation in patient cells, and multiple approved TKIs plus selective allosteric DDR2 inhibitors are available for testing.

Evidence Base

PMID Study How it supports / challenges findings
30449416 Recurrent, Activating Variants in DDR2 Cause WCS (Xu et al. 2018) Foundational. Defines gene, two recurrent variants, AD inheritance, core phenotype, GOF mechanism, and dasatinib rationale.
41259339 WCS variant p.Tyr740Cys enhances DDR2 kinase catalytic activity (Hao & Leitinger 2025) Confirms both variants are constitutively autophosphorylated and bypass autoinhibition; kinetic proof of GOF.
39095787 Progressive conjunctival invasion of cornea in a child with WCS (Ben 2024) Documents ultra-rarity (~6 cases), trauma-provoked progression, and surgical recurrence.
41778429 Novel mutation, neonatal WCS case (Xiao 2025) Expands mutational spectrum and onset to neonatal period (choanal/respiratory presentation).
28270508 DDR2 mediates collagen-induced MT1-MMP activation in human fibroblasts (Majkowska 2017) Links DDR2 to MT1-MMP/pro-MMP-2 in the effector cell of WCS.
25733533 DDR2 inhibition reduces MMP2/9 via ERK/NF-κB (Poudel 2015) Establishes the ERK/NF-κB → MMP signaling axis.
33882324 Active MT1-MMP tethered to collagen in DDR2 remnants (Feng 2021) Mechanism for sustained ECM degradation.
40796038 DDRs as anti-fibrotic target — review (Gong 2025) Positions DDR2 as a broad anti-fibrotic drug target.
24725424 / 24361528 DDR function in physiology/disease (Leitinger 2014; Vogel 2014) Frame DDR2 biology, fibrosis, and inflammation roles.
18938156 Imatinib, nilotinib, dasatinib inhibit DDR1/2 (Day 2008) Expands the repurposing pool of DDR2 inhibitors.
41955962 WRG-28 selective DDR2 inhibitor in OA (2026) Provides a selective allosteric DDR2 inhibitor candidate.
11375938 DDR2 regulates proliferation; elimination → dwarfism (Labrador 2001) LOF mouse model — skeletal + wound-healing roles.
42323896 DDR2 disruption → palate malformations (Capecki 2026) LOF zebrafish model — craniofacial/palate link.
24725993 / 36720430 Biallelic LOF DDR2 → SMED-SL (Al-Kindi 2014; Akalın 2023) Define the allelic, mechanistically opposite recessive disorder.

Limitations and Knowledge Gaps

  1. Extreme rarity. With fewer than ~10 reported individuals, no epidemiology (prevalence/incidence), penetrance, expressivity, survival, or QoL statistics can be calculated. Phenotype frequencies from HPOA rest on a very small denominator.
  2. No gain-of-function animal model. Every available in-vivo model is LOF (Ddr2-null mouse, ddr2-knockdown zebrafish), which recapitulates SMED-SL, not WCS. A knock-in GOF model is the single biggest missing tool.
  3. No WCS-specific omics. No transcriptomic, proteomic, metabolomic, single-cell, or spatial data exist for patient tissues; mechanistic inference relies on DDR2 cancer/fibroblast surrogates.
  4. Therapy is unproven in humans. Dasatinib/imatinib/nilotinib efficacy is demonstrated at the level of kinase inhibition and patient-cell autophosphorylation only — no clinical trial (NCT) has tested any DDR2 inhibitor in WCS, and TKI toxicity in a chronic, pediatric-onset setting is a serious concern.
  5. Genotype–phenotype spectrum unclear. Whether the novel neonatal variant behaves identically to the two hotspots, and what determines variable expressivity, is unknown.
  6. Ontology mapping incomplete. No Orphanet, ICD, or MeSH code exists, complicating registry-based case finding.

Proposed Follow-up Experiments / Actions

  1. Generate a knock-in GOF model. Create Ddr2^L610P^ and Ddr2^Y740C^ knock-in mice (and/or zebrafish) to test whether they recapitulate corneal neovascularization, keloids, and acro-osteolysis, and to serve as a preclinical drug-testing platform.
  2. Preclinical TKI dose-response. Systematically compare dasatinib, imatinib, nilotinib, and selective allosteric inhibitors (e.g., WRG-28) in patient fibroblasts and the new GOF model for suppression of autophosphorylation, ERK/NF-κB, and MMP/MT1-MMP output, with careful attention to therapeutic index.
  3. N-of-1 / basket clinical evaluation. Given mechanistic clarity and drug availability, pursue carefully monitored compassionate-use or n-of-1 trials of a DDR2 inhibitor (with local/topical formulation considered for the ocular surface to limit systemic toxicity), registering an NCT.
  4. Patient-tissue multi-omics. Perform single-cell/spatial transcriptomics and proteomics on WCS keloid, ulcer margin, and corneal pannus tissue to map fibroblast subpopulations and confirm the ERK/NF-κB/MMP program in situ.
  5. International registry & GeneMatcher outreach. Aggregate all known cases to define natural history, penetrance, expressivity, and genotype–phenotype correlations; seek an Orphanet/ICD-11 code.
  6. Biomarker development. Validate DDR2 phosphorylation and circulating MMP-2/9/13 as pharmacodynamic biomarkers for future trials.

Evidence-source key: human clinical (case reports/cohorts) — PMIDs 30449416, 39095787, 41778429, 35036505; in vitro / biochemical — 41259339, 28270508, 25733533, 33882324, 18938156, 41955962; model organism — 11375938, 42323896; review/synthesis — 40796038, 24725424, 24361528; allelic disorder — 24725993, 36720430; ontology cross-references verified via EBI OLS4 (MONDO) and Monarch/HPOA.

Artifacts

Reference Validation

Checked with linkml-reference-validator 0.2.1.

Outcome Count
References checked 16
Resolved 16
Unresolved (possible confabulation) 0
Unverifiable 0
References weighed for topical relevance 16
On topic 4
Off topic 0

All extracted references resolved successfully.

Term Validation

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

Outcome Count
Terms checked 55
Resolved 52
Unresolved (possible confabulation) 0
Obsolete 1
Unverifiable 2
Terms whose name was checked 31
Terms named correctly 20
Terms named as a different term 4
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:0032579 (3 mentions) - the report calls it "MONDO"; MONDO calls it warburg-cinotti syndrome
  • EFO:0010166 (1 mention) - the report calls it "EFO"; EFO calls it Warburg-Cinotti syndrome
  • NCIT:C62035 (1 mention) - the report calls it "Potent DDR1/2 inhibitor (PMID: 18938156)"; NCIT calls it Imatinib
  • NCIT:C48375 (1 mention) - the report calls it "Potent DDR1/2 inhibitor (PMID: 18938156)"; NCIT calls it Nilotinib

Obsolete terms

These terms are real but deprecated. Citing one is not a fabrication; it does mean the report is naming something the ontology has retired:

  • GO:0062023 (obsolete collagen-containing extracellular matrix) (1 mention) - replaced by GO:0031012

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:

  • HP:0011496 (2 mentions) - the report calls it "Progressive corneal neovascularization", "Corneal neovascularization"; HP calls it Corneal neovascularization
  • HP:0001058 (2 mentions) - the report calls it "Chronic skin ulcers / poor wound healing", "Poor wound healing"; HP calls it Poor wound healing
  • HP:0012785 (1 mention) - the report calls it "Flexion contractures of the fingers"; HP calls it Flexion contracture of finger
  • HP:0009771 (2 mentions) - the report calls it "Acro-osteolysis / osteolytic phalangeal defects", "Osteolytic defects of phalanges of hand"; HP calls it Osteolytic defects of the phalanges of the hand, and lists "Acro-osteolysis" among its other names
  • HP:0100720 (1 mention) - the report calls it "Hypoplasia of ear cartilage"; HP calls it Hypoplasia of the ear cartilage
  • HP:0000413 (1 mention) - the report calls it "Atresia of external auditory canal"; HP calls it Atresia of the external auditory canal
  • GO:0005576 (1 mention) - the report calls it "extracellular matrix / extracellular region"; GO calls it extracellular region

Terms named inconsistently

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

  • HP:0011496 - called "Progressive corneal neovascularization", "Corneal neovascularization"
  • HP:0001058 - called "Chronic skin ulcers / poor wound healing", "Poor wound healing"
  • HP:0009771 - called "Acro-osteolysis / osteolytic phalangeal defects", "Osteolytic defects of phalanges of hand"
  • HP:0032107 - called "Limbal stem cell deficiency", "limbal stem-cell 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: OMIM.