WWOX-Related Developmental and Epileptic Encephalopathy

Mendelian MONDO:0014533 Pathograph 21 Show in embeddings browser Epilepsy Neurological Disease

WWOX-related developmental and epileptic encephalopathy (WOREE syndrome, DEE28) is an autosomal recessive developmental and epileptic encephalopathy caused by biallelic loss-of-function variants in WWOX, which encodes a WW-domain-containing oxidoreductase acting as a multi-partner scaffold protein. Seizures begin in the first weeks to months of life and are drug-resistant; affected children acquire neither language nor independent walking, and mortality in early childhood is high. WWOX loss acts through several separable routes - dysregulated Wnt/GSK-3beta signalling, failure of oligodendrocyte maturation with CNS hypomyelination, and a cortical excitation-inhibition imbalance measured directly in neuronal-deletion mice - which converge on network hyperexcitability. Genotype is the dominant prognostic axis: biallelic null variants carry significantly lower survival probability than genotypes containing a presumed hypomorphic missense allele, and the milder allelic disorder SCAR12 sits at the missense end of the same spectrum.

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Inheritance

Autosomal recessive HP:0000007

Both syndromes on the WWOX allelic spectrum - WOREE/DEE28 and SCAR12 - require biallelic pathogenic variants. Heterozygous carriers are unaffected, and WWOX is not haploinsufficient.

Autosomal recessive inheritance

Show evidence (1 reference)

PMID:33916893 SUPPORT Human Clinical

"Patients harboring pathogenic germline bi-allelic WWOX variants have been described with the rare devastating neurological syndromes autosomal recessive spinocerebellar ataxia 12 (SCAR12) (6 patients) and WWOX-related epileptic encephalopathy (DEE28 or WOREE syndrome) (56 patients)."

States the biallelic requirement and names both disorders on the allelic spectrum, with the published case counts.

Discussions and Knowledge Gaps

Neuronal WWOX loss produces both hypomyelination and a cortical excitation-inhibition imbalance in the same animals. Which of the two actually generates the seizures, and is the myelin arm causal or merely concurrent?

CONTROVERSY OPEN controversy_myelin_versus_synaptic_route_to_seizures

Attached to

pathophysiology#CNS Hypomyelination pathophysiology#Impaired Axonal Conductivity pathophysiology#Cortical Excitation-Inhibition Imbalance

This is not a manufactured gap - the electrophysiology paper states the problem in as many words, noting that hypomyelination alone does not necessarily cause epilepsy and citing demyelinating conditions that are not epileptic. Both arms are present in the same neuronal-deletion mouse and in WWOX-deleted human organoids, so co-occurrence is established and precedence is not. The pathograph therefore carries them as parallel arms from the scaffold node rather than placing myelin upstream of excitability, which would assert exactly the causal claim in dispute. It matters therapeutically: a remyelinating strategy and an excitability-directed strategy target different arms, and the gene-replacement result cannot separate them because restoring WWOX rescues both at once.

Proposed experiments

Uncouple myelin repair from WWOX restoration in the conditional mouse

exp_remyelination_without_wwox_restoration

Treat neuronal Wwox-deletion mice with a promyelinating agent that does not restore WWOX, and ask whether seizure burden and neocortical bursting fall while excitability measures are held constant. If myelin repair alone suppresses seizures, the myelin arm is causal; if bursting persists at restored myelin content, the synaptic arm is the seizure driver and myelin is concurrent.

Show evidence (2 references)

PMID:34634460 SUPPORT Model Organism

"hypomyelination alone does not necessarily cause epilepsy"

The explicit statement that the myelin arm is not sufficient, which is what makes this a live disagreement rather than an unexamined assumption.

PMID:33914858 SUPPORT Model Organism

"These findings provide cellular and molecular evidence for myelination defects and hyperexcitability in the WOREE syndrome linked to neuronal function of WWOX."

Establishes that both arms follow neuronal WWOX loss, but states them as co-occurring findings rather than as a causal sequence - which is the whole difficulty.

Every rodent model of WWOX loss dies within two to four weeks of birth, while the human disease runs for years and the longest-followed patient reached 40. What can a model that never survives past infancy establish about a progressive disorder?

HUMAN MODEL MISMATCH OPEN mismatch_model_lifespan_versus_human_disease_course

Attached to

pathophysiology#Progressive Cerebral and Optic Atrophy pathophysiology#Genotype-Stratified Mortality Risk

The mismatch is structural rather than a matter of degree. Progressive cerebral atrophy in patients is documented over years of serial imaging; the mouse is dead before an equivalent interval has elapsed, so the degeneration it shows is compressed into a window that cannot be mapped onto the human course. The same limit applies to the therapeutic endpoint: the gene-therapy experiment scores rescue of premature lethality at two to four weeks, an endpoint whose human counterpart - death in early childhood - occurs in only a subset of patients and at a very different point in development. The genotype-stratified survival data make this sharper still, because the human severity spectrum runs from death in infancy to survival into a fifth decade, and no current model spans it. Note this is a mismatch in translational reach, not evidence that the models are wrong: the same models supply the mechanistic measurements this entry depends on.

Proposed experiments

Adult-onset inducible Wwox deletion to model the chronic phase

exp_inducible_adult_onset_wwox_deletion

Use a tamoxifen-inducible neuronal Cre to delete Wwox after the postnatal window that kills the constitutive model, then follow atrophy, myelin content and seizure burden longitudinally. This would separate the developmental contribution from the degenerative one, which the constitutive models necessarily conflate, and give the progressive arm a model with a survivable time course.

Show evidence (2 references)

PMID:33914858 SUPPORT Model Organism

"specific neuronal deletion of murine Wwox produces phenotypes typical of the Wwox-null mutation leading to brain hyperexcitability, intractable epilepsy, ataxia and postnatal lethality"

Postnatal lethality is a defining feature of the model, and is the constraint this mismatch turns on.

PMID:39507621 SUPPORT Human Clinical

"This report presents for the first time a clinical case of an adult patient with a homozygous likely pathogenic variant (p.Thr12Met) in the WWOX gene, with more than 40 years of follow-up."

The far end of the human survival range, four decades beyond anything the rodent models can reach.

Lithium abolishes chemically induced seizures in Wwox-null mice by inhibiting GSK-3beta. Does that translate to the spontaneous, drug-resistant seizures of WOREE syndrome in children?

KNOWLEDGE GAP OPEN gap_gsk3b_as_a_druggable_node

Attached to

pathophysiology#Wnt/GSK-3beta Signalling Dysregulation

This is the only node in the pathograph with an existing drug pointed at it, which makes the gap worth stating precisely rather than optimistically. Two things separate the mouse result from a clinical claim. The rescue was measured against pentylenetetrazol-induced seizures - a provoked-threshold assay - whereas the human disease is defined by spontaneous, drug-resistant seizures, and a compound can raise a chemical seizure threshold without touching established epileptogenic networks. Lithium is also not a selective GSK-3beta inhibitor, so the experiment licenses "GSK-3beta inhibition raises seizure threshold in this model" rather than identifying lithium as the agent. Against that, the target is attractive precisely because it is reachable with existing drugs in a disorder where 95% of patients fail conventional medication.

Proposed experiments

Selective GSK-3beta inhibition against spontaneous seizures

exp_selective_gsk3b_inhibition_spontaneous_seizures

Treat neuronal Wwox-deletion mice - which have spontaneous seizures, unlike the PTZ paradigm - with a selective GSK-3beta inhibitor rather than lithium, and score spontaneous seizure frequency on continuous video EEG together with neocortical bursting in slices. This tests the target rather than the drug, and against the endpoint that matters clinically.

Show evidence (2 references)

PMID:32000863 SUPPORT Model Organism

"Inhibition of GSK3β by lithium ion significantly abolishes the onset of PTZ-induced seizure in Wwox-/- mice."

The result itself, and the wording - PTZ-induced - is exactly the limit the gap turns on.

PMID:33916893 SUPPORT Human Clinical

"Knowledge of the underlying pathophysiology of these syndromes, the range of variants of the WWOX gene and its genotype-phenotype correlations is limited, hampering therapeutic efforts."

States that mechanistic knowledge is the current bottleneck for therapy, which is the context that makes a single druggable node significant.

Genotype class predicts survival, with missense-containing genotypes faring better than biallelic null. Is that because missense alleles retain partial function, or because they do something qualitatively different?

KNOWLEDGE GAP OPEN gap_are_missense_alleles_truly_hypomorphic

Attached to

pathophysiology#Genotype-Stratified Mortality Risk pathophysiology#Loss of WWOX Scaffold Function

The survival difference is the best-quantified genotype-phenotype relationship in this disorder, and the word doing the work in the source is "presumed" - the hypomorphic status of missense alleles is inferred from the milder outcome rather than measured. This matters mechanistically because WWOX is a multi-domain scaffold: a missense change in a WW domain could preserve SDR-domain function while abolishing one protein interaction, which is not the same thing as uniformly reduced dose, and would predict arm-selective rather than globally milder disease. No published assay measures residual WWOX function allele by allele, so the dose-response model underlying the entire WOREE-to-SCAR12 spectrum rests on clinical severity rather than on protein function. It also bears directly on gene replacement, whose rationale assumes that adding functional protein back is sufficient regardless of which allele is present.

Proposed experiments

Residual-function assay across a WWOX missense allele series

exp_allele_series_residual_function

Express each recurrent patient missense allele in a WWOX-null human neuronal background and measure, per allele, partner binding through each WW domain, the Hyal-2/Smad4 nuclear relocation readout, and rescue of the organoid hyperexcitability phenotype. A graded series would support the hypomorph model; arm-selective loss - one allele rescuing signalling but not excitability - would refute it and predict that genotype classes differ in kind rather than degree.

Show evidence (2 references)

PMID:36779245 SUPPORT Human Clinical

"patients with biallelic null WWOX pathogenic variants have significantly lower survival probability compared to those carrying at least one presumed hypomorphic missense pathogenic variant"

The survival result, and the word "presumed" marking the hypomorphic status as an inference rather than a measurement.

PMID:33916893 SUPPORT Human Clinical

"Therefore, there is a critical need to identify and consolidate all the reported variants in WWOX to distinguish between disease-causing alleles and their associated severity, and benign variants, with the aim of improving diagnosis and increasing therapeutic efforts."

An explicit statement that allele-level severity assignment is unfinished work.

⚙

Pathophysiology

Biallelic WWOX Loss-of-Function Lesion

Two pathogenic WWOX alleles are present - homozygous or compound heterozygous - spanning nonsense, frameshift, splice-site, missense and copy-number variants. This node records the lesion only; the genotype class it falls into is modelled separately, because that is what the outcome data stratify on.

Downstream

Loss of WWOX Scaffold Function Both alleles fail, so no functional WWOX protein is available to its partners.

Show evidence (2 references)

PMID:30356099 SUPPORT Human Clinical

"Two copy-number variations (CNVs) or two single-nucleotide variations (SNVs) were found respectively in four and nine families, with compound heterozygosity for one SNV and one CNV in five families."

Documents the biallelic requirement and the mixed SNV/CNV allele architecture in the largest published cohort.

PMID:24456803 SUPPORT Human Clinical

"we identified a homozygous WWOX nonsense mutation, p.Arg54*, in a girl from a consanguineous family with a severe syndrome of growth retardation, microcephaly, epileptic seizures, retinopathy and early death"

The index observation establishing biallelic WWOX loss as the cause of this lethal recessive syndrome.

Loss of WWOX Scaffold Function

WWOX is a 46 kDa adaptor carrying two N-terminal WW domains and a C-terminal short-chain dehydrogenase/reductase domain. The WW domains bind PPxY-motif partners, so the protein acts as a hub rather than through a single catalytic output - its own substrate is still unknown. Loss of the hub is what propagates into the separate signalling arms below.

neuron CL:0000540

Animal models

AAV9-Synapsin I-WWOX gene replacement in Wwox-null mice Mouse rescues Neuron-restricted restoration of the missing protein rescues hyperexcitability and seizures, myelination deficits, and premature lethality together.

Downstream

Wnt/GSK-3beta Signalling Dysregulation Loss of the WWOX hub releases GSK-3beta from normal restraint.

Hyal-2/WWOX/Smad4 Complex Failure WWOX is the bridge subunit of this complex, so its loss prevents assembly.

Impaired Oligodendrocyte Maturation Neuronal WWOX loss lowers myelination-gene transcript levels; the steps between the scaffold and that transcriptional change are not established.

Disrupted Cortical Neuronal Migration Developmental malformations follow WWOX loss, but no single signalling arm has been shown to account for them.

Show evidence (1 reference)

PMID:39507621 SUPPORT Human Clinical

"This protein contains two N-terminal WW domains (referred to as WW1 and WW2) and a catalytic domain in the C-terminus, which is homologous to short-chain dehydrogenase/reductase (SDR) family proteins, although the substrate of WWOX is currently unknown."

Gives the domain architecture and states explicitly that the catalytic substrate is unknown, which is why this node is scoped to scaffold function.

Wnt/GSK-3beta Signalling Dysregulation

WWOX loss produces significantly increased activation of glycogen synthase kinase 3beta across cerebral cortex, hippocampus and cerebellum in Wwox-null mice. This arm is separated from the others because it carries its own pharmacological test: inhibiting GSK-3beta with lithium abolishes induced seizures in these animals.

Wnt signaling pathway GO:0016055 ↕ DYSREGULATED

Animal models

Wwox-null mouse (germline knockout) Mouse recapitulates The only node in this pathograph with a pharmacological intervention attached: GSK-3beta activation rises, and inhibiting it with lithium abolishes induced seizures.

Downstream

Neocortical Network Hypersynchrony GSK-3beta inhibition suppresses induced seizures, placing this arm upstream of network-level hyperexcitability; the intervening steps are not mapped.

Show evidence (1 reference)

PMID:32000863 SUPPORT Model Organism

"Inhibition of GSK3β by lithium ion significantly abolishes the onset of PTZ-induced seizure in Wwox-/- mice."

The pharmacological result that makes this a causal arm for seizures rather than a correlated biochemical change.

Hyal-2/WWOX/Smad4 Complex Failure

In a non-canonical TGF-beta route, hyaluronan-bound membrane hyaluronidase Hyal-2 recruits WWOX and Smad4 into a complex that relocates to the nucleus. WWOX is the bridge that binds both partners, so in its absence Smad relocation fails. Curated as a distinct arm because it is a transcriptional-signalling defect, not a synaptic or myelin one.

transforming growth factor beta receptor signaling pathway GO:0007179 ↓ DECREASED

Show evidence (1 reference)

PMID:27845895 SUPPORT In Vitro

"In WWOX-deficient cells, HA failed to induce Smad2/3/4 relocation to the nucleus."

The direct loss-of-function measurement for this arm: without WWOX the signalling complex does not reach the nucleus.

Impaired Oligodendrocyte Maturation

Oligodendrocyte precursors fail to mature into myelinating oligodendrocytes, with a measured fall in myelination-gene transcripts. Kept separate from the hypomyelination it produces, because the cellular differentiation failure and the tissue-level myelin deficit are distinct measurements.

oligodendrocyte precursor cell CL:0002453 oligodendrocyte CL:0000128

oligodendrocyte differentiation GO:0048709 ↓ DECREASED

Animal models

Synapsin-Cre neuronal conditional Wwox knockout mouse Mouse recapitulates Establishes the striking part of the myelin arm - deleting Wwox from *neurons* is sufficient to impair oligodendrocyte maturation, so the myelin defect is non-cell-autonomous.

Downstream

CNS Hypomyelination Fewer mature oligodendrocytes produce less myelin.

Show evidence (1 reference)

PMID:33914858 SUPPORT Model Organism

"A significant decrease in transcript levels of genes involved in myelination was observed in mouse cortex and hippocampus."

The transcriptional measurement upstream of the cellular maturation failure.

CNS Hypomyelination

Reduced myelinated axon content in the central nervous system. Whether this arm contributes causally to the seizures, as opposed to running in parallel with them, is an open question recorded in the discussions.

myelination GO:0042552 ↓ DECREASED

Experimental models

WWOX-deleted human brain organoid ORGANOID Reproduces both hyperexcitability and hypomyelination at the human gene dose, which is what stops the myelin arm resting on mouse data alone.

Downstream

Impaired Axonal Conductivity Reduced myelin slows and degrades axonal conduction.

Show evidence (2 references)

PMID:33914858 SUPPORT Model Organism

"Wwox-mutant mice exhibited reduced maturation of oligodendrocytes, reduced myelinated axons and impaired axonal conductivity."

Reports the myelin deficit and the conduction consequence in the same neuronal-deletion model.

PMID:33914858 SUPPORT In Vitro

"Brain hyperexcitability and hypomyelination were also revealed in human brain organoids with a WWOX deletion."

Confirms the myelin phenotype at the human gene dose, not only in mouse.

Impaired Axonal Conductivity

Axonal conduction is measurably impaired in neuronal Wwox-deletion mice. Recorded as its own node because it is the functional consequence of hypomyelination and the point at which the myelin arm could in principle act on network behaviour.

Show evidence (1 reference)

PMID:33914858 SUPPORT Model Organism

"Wwox-mutant mice exhibited reduced maturation of oligodendrocytes, reduced myelinated axons and impaired axonal conductivity."

The conduction measurement itself.

Disrupted Cortical Neuronal Migration

A developmental arm separate from the synaptic and myelin arms: Wwox-null mice show neuronal disorganisation and heterotopia, incomplete separation of the cerebral hemispheres, and defective cerebellar midline fusion.

hippocampus development GO:0021766 ⚠ ABNORMAL

Animal models

Wwox-null mouse (germline knockout) Mouse recapitulates Reproduces the malformation arm - heterotopia, disordered neurons, incomplete hemispheric separation and defective cerebellar midline fusion.

Downstream

Profound Developmental Impairment Malformed cortex plausibly contributes to the developmental phenotype, which the seizure burden also drives independently.

Show evidence (1 reference)

PMID:32000863 SUPPORT Model Organism

"Cerebral malformations, such as microcephaly and incomplete separation of the hemispheres by a partial interhemispheric fissure, neuronal disorganization and heterotopia, and defective cerebellar midline fusion are observed in Wwox-/- mice."

Documents the migration and midline patterning defects that make this a developmental rather than purely functional arm.

Increased Excitatory Synaptic Drive

Layer II/III pyramidal neurons show elevated excitatory postsynaptic current amplitude. Curated separately from the inhibitory change because the two were measured separately and move in opposite directions - collapsing them into one "E/I imbalance" node would discard which side actually changed.

pyramidal neuron CL:0000598

Animal models

Synapsin-Cre neuronal conditional Wwox knockout mouse Mouse recapitulates Supplies the direct synaptic measurement for the excitatory side of the imbalance.

Downstream

Cortical Excitation-Inhibition Imbalance More excitatory drive shifts the cortical balance toward excitation.

Show evidence (1 reference)

PMID:34634460 SUPPORT Model Organism

"In layer II/III pyramidal neurons, Wwox knockout mice demonstrated elevated amplitude of excitatory post-synaptic currents, whereas the frequency and amplitude of inhibitory post-synaptic currents were reduced, as compared to heterozygote and wild-type littermate controls."

Reports the excitatory amplitude increase, against littermate controls.

Reduced Inhibitory Synaptic Drive

The same layer II/III recordings show reduced frequency and amplitude of inhibitory postsynaptic currents - a loss of inhibition running alongside, and independent of, the gain in excitation.

pyramidal neuron CL:0000598

Animal models

Synapsin-Cre neuronal conditional Wwox knockout mouse Mouse recapitulates Supplies the inhibitory side of the same measurement, which moves in the opposite direction and is therefore a separate claim.

Downstream

Cortical Excitation-Inhibition Imbalance Less inhibitory drive shifts the same balance from the other side.

Show evidence (1 reference)

PMID:34634460 SUPPORT Model Organism

The same recording reports the inhibitory reduction; it is quoted on both nodes because it is one measurement supporting two separable claims.

Intrinsic Neuronal Hyperexcitability

Beyond synaptic drive, the neurons themselves are altered: depolarised resting membrane potential, increased action-potential frequency, increased sag current and post-inhibitory rebound. This is a membrane-property change, not a synaptic one, so it is a third independent contributor rather than part of the E/I node.

pyramidal neuron CL:0000598

Downstream

Neocortical Network Hypersynchrony More excitable neurons fire more readily into the network.

Show evidence (1 reference)

PMID:34634460 SUPPORT Model Organism

"Furthermore, these neurons were depolarized and demonstrated increased action potential frequency, sag current, and post-inhibitory rebound."

The intrinsic membrane measurements, distinct from the synaptic currents above.

Cortical Excitation-Inhibition Imbalance

The net shift of neocortical circuits toward excitation, produced by the independent gain in excitatory drive and loss of inhibitory drive above.

Downstream

Neocortical Network Hypersynchrony An excitation-shifted cortex supports synchronous bursting.

Show evidence (1 reference)

PMID:34634460 SUPPORT Model Organism

"These findings suggest WWOX plays an essential role in balancing neocortical excitability and provide insight towards developing therapeutics for those suffering from WWOX disorders."

The authors' own statement of the balance role this node represents.

Neocortical Network Hypersynchrony

Spontaneous bursting appears in neocortical but not hippocampal slices, is NMDA receptor- and gap-junction-dependent, and propagates from layer II/III to layer V - so the neocortex, and specifically its superficial layers, is the driver.

Animal models

Synapsin-Cre neuronal conditional Wwox knockout mouse Mouse recapitulates Locates the bursting anatomically - present in neocortical but not hippocampal slices - and pharmacologically, as NMDA receptor- and gap-junction-dependent.

Downstream

Early-Onset Drug-Resistant Seizures Hypersynchronous cortical networks generate clinical seizures.

Show evidence (2 references)

PMID:34634460 SUPPORT Model Organism

"identified spontaneous bursting activity in the neocortex, a marker of the underlying network hyperexcitability"

The network-level measurement this node records.

PMID:34634460 SUPPORT Model Organism

"These bursts were NMDAR and gap junction dependent."

Identifies the pharmacological dependencies of the bursting, which constrain which mechanisms can be generating it.

Early-Onset Drug-Resistant Seizures

Multiple seizure types begin within the first weeks to months of life - most often focal seizures, epileptic spasms and tonic seizures - and respond poorly to antiseizure medication.

Downstream

Profound Developmental Impairment Continuous early-life seizure burden plausibly compounds the developmental phenotype that the malformation arm already produces.

Show evidence (2 references)

PMID:36779245 SUPPORT Human Clinical

"the most frequent being focal (85%), epileptic spasms (77%), and tonic seizures (69%)"

Gives the seizure-type distribution, each patient having multiple types.

PMID:30356099 SUPPORT Human Clinical

"This review suggests WOREE syndrome is a very severe epileptic encephalopathy characterized by absence of language development and acquisition of walking, early-onset drug-resistant seizures, ophthalmological involvement, and a high likelihood of premature death."

Establishes early onset and drug resistance as defining features.

Progressive Cerebral and Optic Atrophy

A degenerative arm distinct from the malformation arm: severe frontotemporal, hippocampal and optic atrophy with thin corpus callosum and white matter signal change on patient MRI, mirrored in mice by optic nerve atrophy, Purkinje cell loss and cerebellar granule cell apoptosis.

regulation of neuron apoptotic process GO:0043523 ⚠ ABNORMAL

Animal models

Wwox-null mouse (germline knockout) Mouse recapitulates Supplies the cellular resolution the human MRI cannot - Purkinje cell loss, granule cell apoptosis and optic nerve atrophy.

Show evidence (2 references)

PMID:36779245 SUPPORT Human Clinical

"Brain MRIs revealed severe frontotemporal, hippocampal, and optic atrophy, thin corpus callosum, and white matter signal abnormalities."

The human imaging evidence for the degenerative arm.

PMID:32000863 SUPPORT Model Organism

"Degenerative alterations including severe hypomyelination in the central nervous system, optic nerve atrophy, Purkinje cell loss and granular cell apoptosis in the cerebellum"

The corresponding cellular degeneration in the mouse, which the human MRI cannot resolve.

Profound Developmental Impairment

Affected children acquire neither language nor independent walking. Two upstream routes converge here - the developmental malformation arm and the seizure burden - and the published data do not separate their contributions.

Show evidence (1 reference)

PMID:33916893 SUPPORT Human Clinical

"the most common clinical symptoms being severe epileptic encephalopathy and profound global developmental delay"

Names the developmental phenotype as one of the two most common features.

Genotype-Stratified Mortality Risk

Survival tracks genotype class rather than any single clinical feature: biallelic null genotypes have significantly lower survival probability than genotypes carrying at least one presumed hypomorphic missense allele. This is the entry's best-quantified genotype-phenotype claim and the reason the lesion node and the genotype class are modelled separately.

Show evidence (2 references)

PMID:36779245 SUPPORT Human Clinical

"patients with biallelic null WWOX pathogenic variants have significantly lower survival probability compared to those carrying at least one presumed hypomorphic missense pathogenic variant"

The survival comparison by genotype class, from a formal survival analysis.

PMID:30356099 SUPPORT Human Clinical

"The most severe clinical presentation seems to be associated with null genotypes."

An independent cohort reaching the same genotype-severity conclusion, in deliberately hedged language.

⬡

Pathograph

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

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Phenotypes

Digestive 1

Feeding difficulties FREQUENT HP:0011968

Show evidence (1 reference)

PMID:30356099 SUPPORT Human Clinical

"Feeding difficulties were observed in most of the patients and 13/19 (70%) required a feeding tube."

13 of 19 is 68%, in the FREQUENT band. The band is taken against tube dependence, the harder endpoint, rather than against the vaguer 'most of the patients' for feeding difficulty in general.

Eye 2

Optic atrophy FREQUENT HP:0000648

Show evidence (1 reference)

PMID:36779245 SUPPORT Human Clinical

"Brain MRIs revealed severe frontotemporal, hippocampal, and optic atrophy, thin corpus callosum, and white matter signal abnormalities."

Optic atrophy is reported in the same imaging series.

Retinal dystrophy OCCASIONAL HP:0000556

Show evidence (1 reference)

PMID:30356099 SUPPORT Human Clinical

"Retinal dystrophy was diagnosed in 2/19 (10%) patients and optic nerve anomalies in 10/19 (53%)."

2 of 19 is 11%, in the 5-29% OCCASIONAL band - and an order of magnitude less frequent than the optic nerve anomalies reported in the same sentence, which is why the two are separate phenotypes.

Head and Neck 2

Microcephaly OCCASIONAL HP:0000252

Show evidence (2 references)

PMID:30356099 SUPPORT Human Clinical

"4 of 20 (20%) patients had microcephaly (defined by OFC"

4 of 20 is 20%, in the 5-29% OCCASIONAL band. The quote stops before the threshold definition because the following span contains a minus sign that does not survive snippet matching; the definition is given in the description instead.

PMID:24456803 SUPPORT Human Clinical

Microcephaly in the index case, which is where the association was first made.

Abnormal facial shape FREQUENT HP:0001999

Show evidence (1 reference)

PMID:30356099 SUPPORT Human Clinical

"Facial dysmorphism was reported in 12 of 20 (60%) individuals."

12 of 20 is 60%, in the FREQUENT band.

Musculoskeletal 3

Hypotonia FREQUENT HP:0001252

Show evidence (1 reference)

PMID:30356099 SUPPORT Human Clinical

"Hypotonia (mostly axial) was observed in 15 of 20 (75%) patients and hypertonia (mostly distal) in 15 of 18 (83%)."

15 of 20 is 75%, in the 30-79% FREQUENT band. Curated separately from the hypertonia in the same sentence because the two are opposite tone abnormalities affecting different body regions - axial versus distal - and are counted against different denominators.

Hypertonia VERY_FREQUENT HP:0001276

Show evidence (1 reference)

PMID:30356099 SUPPORT Human Clinical

"Hypotonia (mostly axial) was observed in 15 of 20 (75%) patients and hypertonia (mostly distal) in 15 of 18 (83%)."

15 of 18 is 83%, in the 80-99% VERY_FREQUENT band. The coexistence of distal hypertonia with axial hypotonia in the same cohort is why these are two phenotypes rather than one tone abnormality.

Scoliosis FREQUENT HP:0002650

Show evidence (1 reference)

PMID:30356099 SUPPORT Human Clinical

"Scoliosis or kyphosis was present in 13 of 20 (65%) patients."

13 of 20 is 65%, in the FREQUENT band. The count covers scoliosis or kyphosis together, so it is not a scoliosis-only rate.

Nervous System 10

Seizures OBLIGATE HP:0001250

Onset: INFANTILE

Show evidence (1 reference)

PMID:36779245 SUPPORT Human Clinical

"All patients experienced multiple seizure types"

Every patient in the cohort had seizures, and more than one type, which is what justifies the OBLIGATE band rather than a merely high frequency.

Focal-onset seizure VERY_FREQUENT HP:0007359

Show evidence (1 reference)

PMID:36779245 SUPPORT Human Clinical

"the most frequent being focal (85%), epileptic spasms (77%), and tonic seizures (69%)"

85% falls in the 80-99% VERY_FREQUENT band.

Epileptic spasm FREQUENT HP:0011097

Show evidence (1 reference)

PMID:36779245 SUPPORT Human Clinical

"the most frequent being focal (85%), epileptic spasms (77%), and tonic seizures (69%)"

77% falls in the 30-79% FREQUENT band, just below the VERY_FREQUENT threshold.

Tonic seizure FREQUENT HP:0032792

Show evidence (1 reference)

PMID:36779245 SUPPORT Human Clinical

"the most frequent being focal (85%), epileptic spasms (77%), and tonic seizures (69%)"

69% falls in the 30-79% FREQUENT band.

Profound global developmental delay VERY_FREQUENT HP:0012736

Show evidence (1 reference)

PMID:33916893 SUPPORT Human Clinical

"the most common clinical symptoms being severe epileptic encephalopathy and profound global developmental delay"

Named as one of the two most common features across the combined cohort. The band is taken as VERY_FREQUENT rather than OBLIGATE because the source says "most common", not "all".

Absent speech VERY_FREQUENT HP:0001344

Show evidence (1 reference)

PMID:30356099 SUPPORT Human Clinical

Absence of language development is named as a defining feature of the syndrome.

Dystonia VERY_FREQUENT HP:0001332

Show evidence (1 reference)

PMID:36779245 SUPPORT Human Clinical

"Eleven of 13 patients had a movement disorder, most frequently dystonia."

11/13 is 85%, in the 80-99% VERY_FREQUENT band. The band is stated for "a movement disorder"; dystonia is the most frequent kind but the quote does not give a separate dystonia-only count.

Developmental regression HP:0002376

Show evidence (1 reference)

PMID:39507621 SUPPORT Human Clinical

"In adolescence, there was an acute regression of acquired skills to a total absence of independent motor activity."

A single-patient observation, so no frequency band is asserted.

Cerebral atrophy FREQUENT HP:0002059

Show evidence (1 reference)

PMID:36779245 SUPPORT Human Clinical

"Brain MRIs revealed severe frontotemporal, hippocampal, and optic atrophy, thin corpus callosum, and white matter signal abnormalities."

Reports the atrophy pattern. The FREQUENT band reflects the roughly half of patients with progressive atrophy in the larger cohort rather than a count in this quote.

Hypoplasia of the corpus callosum FREQUENT HP:0002079

Show evidence (1 reference)

PMID:36779245 SUPPORT Human Clinical

"Brain MRIs revealed severe frontotemporal, hippocampal, and optic atrophy, thin corpus callosum, and white matter signal abnormalities."

Thin corpus callosum is named in the same imaging series.

Respiratory 1

Respiratory insufficiency FREQUENT HP:0002093

Show evidence (1 reference)

PMID:30356099 SUPPORT Human Clinical

"asthma, recurrent infections, irregular breathing pattern, or aspiration pneumonia were reported in 8 of 20 (40%) patients"

8 of 20 is 40%, in the FREQUENT band. The quote starts mid-sentence because the preceding words are broken by a hyphenated line break in the cached PDF text.

Other 5

Inability to walk VERY_FREQUENT HP:0002540

Show evidence (1 reference)

PMID:30356099 SUPPORT Human Clinical

Failure to acquire walking is named alongside absence of language.

Abnormal optic nerve morphology FREQUENT HP:0000587

Show evidence (1 reference)

PMID:30356099 SUPPORT Human Clinical

"Retinal dystrophy was diagnosed in 2/19 (10%) patients and optic nerve anomalies in 10/19 (53%)."

10 of 19 is 53%, in the FREQUENT band.

Abnormal fundus morphology FREQUENT HP:0001098

Show evidence (1 reference)

PMID:30356099 SUPPORT Human Clinical

"Fundus oculi was altered in 9/19 patients (47%)"

9 of 19 is 47%, in the FREQUENT band.

Reduced eye contact FREQUENT HP:0000817

Show evidence (1 reference)

PMID:30356099 SUPPORT Human Clinical

"Of 20 patients, 16 (75%) had no eye contact or poor eye contact."

16 of 20 is 75%, in the FREQUENT band.

Status epilepticus OCCASIONAL HP:0002133

Show evidence (1 reference)

PMID:30356099 SUPPORT Human Clinical

"Few patients had febrile seizures (2/17; 12%) and 4 of 17 (23%) had status epilepticus."

4 of 17 is 24%, in the OCCASIONAL band.

🧬

Genetic Associations

WWOX (Biallelic germline loss-of-function variants in WWOX cause WOREE syndrome (DEE28); the same gene causes the milder allelic disorder SCAR12.)

Gene: WWOX hgnc:12799 relationship_type: CAUSATIVE

Show evidence (3 references)

PMID:30356099 SUPPORT Human Clinical

Documents the allele architecture, including the SNV/CNV compound genotypes that drive the testing recommendation.

PMID:36779245 SUPPORT Human Clinical

"Pathogenic variants were located throughout WWOX and comprised both missense and null changes including five copy number variants (four deletions, one duplication)."

Confirms that variants are distributed across the gene rather than clustered in a hotspot, and that CNVs are a substantial fraction.

PMID:30356099 SUPPORT Human Clinical

"Four missense variations were recurrent: p.(Gln230Pro) was found in four families, p.(Gly137Glu) in three families"

Records the recurrent missense alleles. Note this sits alongside, and does not contradict, the statement above that variants are distributed throughout the gene - recurrence here reflects a handful of repeated alleles rather than a mutational hotspot.

💊

Medical Actions

Antiseizure Medication

Action: Pharmacotherapy NCIT:C15986

Conventional antiseizure medications are the mainstay of symptomatic care but control seizures poorly - drug resistance is part of how the syndrome is characterised. This entry does not name a preferred agent, because the cited cohorts report drug resistance as a class property rather than comparing individual drugs.

Show evidence (2 references)

PMID:30356099 SUPPORT Human Clinical

Drug resistance is named as a defining feature, which is the honest framing for this treatment rather than an efficacy claim.

PMID:34747138 SUPPORT Human Clinical

"Response to antiepileptic drugs of these syndromes is very poor, and hence, alternative treatment approaches should be explored and developed."

States the poor response directly, and is the stated rationale for the gene therapy programme below.

WWOX Gene Replacement Therapy

Action: Gene Therapy NCIT:C15238

Experimental, preclinical. A single neonatal intracerebroventricular injection of an AAV9 vector carrying WWOX under a neuronal Synapsin I promoter rescues hyperexcitability, seizures, myelination and survival in Wwox-null mice. No peer-reviewed human efficacy data exist; this is curated as a mechanism-matched strategy with preclinical support, not as available care.

Mechanism Target:

RESTORES Loss of WWOX Scaffold Function — Supplies the missing protein to neurons, addressing the pathograph at its root rather than at any single downstream arm.

Show evidence (1 reference)

PMID:34747138 SUPPORT Model Organism

"specific neuronal restoration of WWOX expression rescued brain hyperexcitability and seizures, hypoglycemia, myelination deficits, and the premature lethality and behavioral deficits of Wwox-null mice"

The rescue result that licenses linking this treatment to the root node.

Show evidence (1 reference)

PMID:34747138 SUPPORT Model Organism

"These findings provide a proof-of-concept for WWOX gene therapy as a promising approach to curing children with WOREE and SCAR12."

The authors state this as proof of concept, which is the level of claim this entry makes.

Nutritional Support

Action: Nutritional Support NCIT:C15433

Most patients have feeding difficulties and the majority come to depend on a feeding tube. This is curated because it is what most affected children actually receive, and because unsafe swallowing drives the aspiration risk behind the respiratory morbidity recorded above - not because any disease-modifying effect is claimed. Scoped to the nutrition rather than to its delivery route: the previous name bundled enteral feeding with gastrostomy placement, which are a dietary intervention and a procedure respectively, and the modality below describes only the former.

Show evidence (1 reference)

PMID:30356099 SUPPORT Human Clinical

"Feeding difficulties were observed in most of the patients and 13/19 (70%) required a feeding tube."

Establishes tube dependence as the usual course rather than an exceptional intervention.

Genetic Counseling

Action: Genetic Counseling NCIT:C15240

Offered to families given autosomal recessive inheritance with unaffected carrier parents, including in consanguineous families where recurrence risk is the presenting concern.

Show evidence (1 reference)

PMID:24456803 SUPPORT Human Clinical

Establishes the consanguineous recessive setting in which counselling and carrier testing apply.

🔬

Diagnosis

Molecular Genetic Testing for Biallelic WWOX Variants

Diagnosis requires demonstrating two pathogenic WWOX alleles. The testing strategy matters more here than in most recessive disorders, because copy-number variants account for a large share of alleles and compound SNV-plus-CNV genotypes are common - a sequencing-only approach would miss one allele in a substantial fraction of families. The original cohort used a combination of dosage, array-based and sequencing methods for that reason.

Whole Exome Sequencing NCIT:C101295

Show evidence (2 references)

PMID:30356099 SUPPORT Human Clinical

"Different molecular screening approaches were used"

The cohort required several methods rather than one. The full enumeration in the source names dosage and array-based approaches alongside sequencing, but it is quoted short here because the bracketed abbreviations inside it are stripped before snippet matching; the companion evidence item below carries the substance.

PMID:30356099 SUPPORT Human Clinical

Quantifies why: 9 of 18 families carry at least one CNV, so an SNV-only strategy would leave half of them without a complete genotype.

Brain MRI

Supportive rather than diagnostic. Corpus callosum hypoplasia and progressive cerebral atrophy are the usual findings, and the atrophy's progression on serial imaging is itself informative about the degenerative arm.

Magnetic Resonance Imaging NCIT:C16809

Show evidence (1 reference)

PMID:36779245 SUPPORT Human Clinical

"Brain MRIs revealed severe frontotemporal, hippocampal, and optic atrophy, thin corpus callosum, and white matter signal abnormalities."

The imaging pattern this modality demonstrates.

Electroencephalography

EEG characterises the seizure disorder, showing multifocal discharges on a slow background with predominance over frontal or temporo-occipital regions.

Electroencephalography NCIT:C38054

Show evidence (1 reference)

PMID:36779245 SUPPORT Human Clinical

"Interictal EEGs demonstrated slow background activity with multifocal discharges, predominantly over frontal or temporo-occipital regions."

The interictal EEG findings.

📊

Prevalence

Worldwide

Cases In Literature Ultra Rare

Around 56 published WOREE cases and 6 SCAR12 cases as of the 2021 review; the largest single cohort aggregates 37 patients from 27 families. No population rate has been estimated, so the count is recorded as literature cases rather than converted to a rate.

Show evidence (2 references)

PMID:33916893 SUPPORT Human Clinical

The published case counts for both disorders on the allelic spectrum.

PMID:30356099 SUPPORT Human Clinical

"By aggregating our patients with all cases reported in the literature, 37 patients from 27 families with WOREE syndrome are known."

The aggregate cohort size at the time of the largest series.

🧫

Experimental Models

WWOX-deleted human brain organoid ORGANOID

Human brain organoids carrying a WWOX deletion, used here as the human-genetic check on two mouse findings.

Pathograph links

CNS Hypomyelination recapitulates fidelity: moderate Reproduces both hyperexcitability and hypomyelination at the human gene dose, which is what stops the myelin arm resting on mouse data alone.

Limitations: Organoids lack vasculature, immune cells and long-term maturation, so they cannot address the progressive atrophy seen on patient MRI; the reported result is also qualitative rather than a quantified myelin measurement.

Readouts

Hyperexcitability and myelination in WWOX-deleted organoids

Direction: DECREASED

Interpretation: Hypomyelination, alongside hyperexcitability, in human tissue.

Show evidence (1 reference)

PMID:33914858 SUPPORT In Vitro

"Brain hyperexcitability and hypomyelination were also revealed in human brain organoids with a WWOX deletion."

The organoid measurement behind this readout.

Show evidence (1 reference)

PMID:33914858 SUPPORT In Vitro

"These findings provide cellular and molecular evidence for myelination defects and hyperexcitability in the WOREE syndrome linked to neuronal function of WWOX."

States the combined mouse-and-organoid conclusion this model contributes to.

🐁

Animal Models

Wwox-null mouse (germline knockout)

Constitutive whole-animal Wwox knockout. Supplies the developmental-malformation and neurodegeneration arms of this entry, and the only pharmacological test of a druggable node in the pathograph.

Species

Mouse

Genotype

Wwox-/- germline knockout

Publication

PMID:32000863

Pathograph links

Disrupted Cortical Neuronal Migration recapitulates fidelity: moderate Reproduces the malformation arm - heterotopia, disordered neurons, incomplete hemispheric separation and defective cerebellar midline fusion.

Limitations: A constitutive whole-animal null removes WWOX from every expressing cell at once, so it cannot separate a neuronal-autonomous migration defect from a non-cell-autonomous one; the neuronal conditional model below exists for that reason. The malformations are also more severe than the nonspecific imaging findings usual in patients.

Readouts

Cortical architecture and midline fusion

Direction: ALTERED

Interpretation: Heterotopia, neuronal disorganisation and defective cerebellar midline fusion.

Show evidence (1 reference)

PMID:32000863 SUPPORT Model Organism

Reports the structural measurements behind this readout.

Show evidence (1 reference)

PMID:32000863 SUPPORT Model Organism

"Here, we report that targeted disruption of Wwox gene in mice causes neurodevelopmental disorders, encompassing abnormal neuronal differentiation and migration in the brain."

Establishes the model as informative for the migration node.

Wnt/GSK-3beta Signalling Dysregulation recapitulates fidelity: moderate The only node in this pathograph with a pharmacological intervention attached: GSK-3beta activation rises, and inhibiting it with lithium abolishes induced seizures.

Limitations: The rescue was measured against pentylenetetrazol-*induced* seizures, not the spontaneous seizures that define the human disease, so it establishes that this arm can gate seizure threshold rather than that it drives the clinical epilepsy. Lithium is also not a selective GSK-3beta inhibitor.

Readouts

GSK-3beta activation in brain

Direction: INCREASED

Interpretation: GSK-3beta activation is significantly increased across cortex, hippocampus and cerebellum.

Show evidence (1 reference)

PMID:32000863 SUPPORT Model Organism

"We determined that a significantly increased activation of glycogen synthase kinase 3β (GSK3β) occurs in Wwox-/- mouse cerebral cortex, hippocampus and cerebellum."

The biochemical measurement behind this readout.

Induced-seizure onset after GSK-3beta inhibition

Direction: ABOLISHED

Interpretation: Lithium abolishes the onset of PTZ-induced seizures in Wwox-null mice.

Show evidence (1 reference)

PMID:32000863 SUPPORT Model Organism

"Inhibition of GSK3β by lithium ion significantly abolishes the onset of PTZ-induced seizure in Wwox-/- mice."

The rescue measurement behind this readout.

Show evidence (1 reference)

PMID:32000863 SUPPORT Model Organism

"Together, our findings reveal that the neurodevelopmental and neurodegenerative deficits in Wwox knockout mice strikingly recapitulate the key features of human neuropathies, and that targeting GSK3β with lithium ion ameliorates epilepsy."

The authors' own claim that this model is informative for the human disease and for the GSK-3beta arm specifically.

Progressive Cerebral and Optic Atrophy recapitulates fidelity: moderate Supplies the cellular resolution the human MRI cannot - Purkinje cell loss, granule cell apoptosis and optic nerve atrophy.

Limitations: Mouse degeneration is compressed into the two to three weeks before postnatal death, whereas the human atrophy is documented over years, so the time course is not comparable even where the endpoints are.

Readouts

Cerebellar and optic nerve degeneration

Direction: INCREASED

Interpretation: Purkinje cell loss, granule cell apoptosis and optic nerve atrophy.

Show evidence (1 reference)

PMID:32000863 SUPPORT Model Organism

"Degenerative alterations including severe hypomyelination in the central nervous system, optic nerve atrophy, Purkinje cell loss and granular cell apoptosis in the cerebellum"

The histological measurements behind this readout.

Synapsin-Cre neuronal conditional Wwox knockout mouse

Deletes Wwox from neurons only. This is the model that isolates the neuron-autonomous contribution, and the one that produced the direct electrophysiological measurements of excitability in this entry.

Species

Mouse

Genotype

Synapsin I-Cre driven neuronal Wwox deletion

Publication

PMID:33914858

Pathograph links

Impaired Oligodendrocyte Maturation recapitulates fidelity: moderate Establishes the striking part of the myelin arm - deleting Wwox from *neurons* is sufficient to impair oligodendrocyte maturation, so the myelin defect is non-cell-autonomous.

Limitations: The intermediate signal from neuron to oligodendrocyte is not identified, so the link is established as a dependency rather than a mechanism.

Readouts

Oligodendrocyte maturation and myelinated axon content

Direction: DECREASED

Interpretation: Reduced oligodendrocyte maturation and fewer myelinated axons after neuron-restricted deletion.

Show evidence (1 reference)

PMID:33914858 SUPPORT Model Organism

"Wwox-mutant mice exhibited reduced maturation of oligodendrocytes, reduced myelinated axons and impaired axonal conductivity."

The cellular and structural measurements behind this readout.

Show evidence (1 reference)

PMID:33914858 SUPPORT Model Organism

"specific neuronal deletion of murine Wwox produces phenotypes typical of the Wwox-null mutation leading to brain hyperexcitability, intractable epilepsy, ataxia and postnatal lethality"

Establishes that the neuronal-only deletion reproduces the null phenotype, which is what makes this model informative.

Increased Excitatory Synaptic Drive recapitulates fidelity: moderate Supplies the direct synaptic measurement for the excitatory side of the imbalance.

Limitations: Recordings are from acute slices at postnatal days 13-17, so they capture an early developmental window rather than the established chronic epilepsy, and an isolated slice cannot report network behaviour in the intact brain.

Readouts

Excitatory postsynaptic current amplitude in layer II/III pyramidal neurons

Direction: INCREASED

Interpretation: EPSC amplitude is elevated relative to heterozygote and wild-type littermates.

Show evidence (1 reference)

PMID:34634460 SUPPORT Model Organism

The voltage-clamp measurement behind this readout.

Reduced Inhibitory Synaptic Drive recapitulates fidelity: moderate Supplies the inhibitory side of the same measurement, which moves in the opposite direction and is therefore a separate claim.

Limitations: Same slice-preparation and developmental-window caveats as the excitatory readout; the recordings do not identify which interneuron populations are responsible.

Readouts

Inhibitory postsynaptic current frequency and amplitude

Direction: DECREASED

Interpretation: Both IPSC frequency and amplitude fall relative to littermate controls.

Show evidence (1 reference)

PMID:34634460 SUPPORT Model Organism

The same recording, quoted for the inhibitory half of the result.

Neocortical Network Hypersynchrony recapitulates fidelity: moderate Locates the bursting anatomically - present in neocortical but not hippocampal slices - and pharmacologically, as NMDA receptor- and gap-junction-dependent.

Limitations: This is in vitro network activity in slices, not an in vivo EEG seizure, so it is a substrate measurement rather than an ictal recording.

Readouts

Spontaneous neocortical bursting

Direction: INCREASED

Interpretation: Spontaneous bursting appears in knockout neocortical slices and is absent from wild-type controls.

Show evidence (1 reference)

PMID:34634460 SUPPORT Model Organism

"identified spontaneous bursting activity in the neocortex, a marker of the underlying network hyperexcitability"

The field-potential measurement behind this readout.

AAV9-Synapsin I-WWOX gene replacement in Wwox-null mice

A neonatal gene-replacement experiment rather than a disease model: restoring WWOX in neurons alone reverses several arms of the pathograph at once, which is the strongest available evidence that they share the same upstream cause.

Species

Mouse

Genotype

Wwox-null treated with AAV9-SynI-WWOX by intracerebroventricular injection

Publication

PMID:34747138

Pathograph links

Loss of WWOX Scaffold Function rescues fidelity: moderate Neuron-restricted restoration of the missing protein rescues hyperexcitability and seizures, myelination deficits, and premature lethality together.

Limitations: Delivered neonatally into a mouse whose disease has barely begun, whereas children are diagnosed after seizure onset; the rescue therefore speaks to prevention rather than reversal. Two of the rescued endpoints - hypoglycemia and premature lethality at two to four weeks - have no direct counterpart in the human course.

Readouts

Seizures, myelination and survival after neuronal WWOX restoration

Direction: RESTORED

Interpretation: Multiple independent phenotypes revert together after restoring the single missing protein in neurons.

Show evidence (1 reference)

PMID:34747138 SUPPORT Model Organism

The rescue measurements behind this readout.

Show evidence (1 reference)

PMID:34747138 SUPPORT Model Organism

"These findings provide a proof-of-concept for WWOX gene therapy as a promising approach to curing children with WOREE and SCAR12."

The authors' framing of the experiment as translational proof of concept.

{ }

Source YAML

click to show

name: WWOX-Related Developmental and Epileptic Encephalopathy
creation_date: "2026-08-19T19:10:00Z"
category: Mendelian
synonyms:
- WOREE syndrome
- WWOX-related epileptic encephalopathy
- Developmental and epileptic encephalopathy 28
- DEE28
- EIEE28
description: >-
  WWOX-related developmental and epileptic encephalopathy (WOREE syndrome, DEE28)
  is an autosomal recessive developmental and epileptic encephalopathy caused by
  biallelic loss-of-function variants in WWOX, which encodes a WW-domain-containing
  oxidoreductase acting as a multi-partner scaffold protein. Seizures begin in the
  first weeks to months of life and are drug-resistant; affected children acquire
  neither language nor independent walking, and mortality in early childhood is
  high. WWOX loss acts through several separable routes - dysregulated Wnt/GSK-3beta
  signalling, failure of oligodendrocyte maturation with CNS hypomyelination, and a
  cortical excitation-inhibition imbalance measured directly in neuronal-deletion
  mice - which converge on network hyperexcitability. Genotype is the dominant
  prognostic axis: biallelic null variants carry significantly lower survival
  probability than genotypes containing a presumed hypomorphic missense allele, and
  the milder allelic disorder SCAR12 sits at the missense end of the same spectrum.
disease_term:
  preferred_term: developmental and epileptic encephalopathy, 28
  term:
    id: MONDO:0014533
    label: developmental and epileptic encephalopathy, 28
parents:
- Epilepsy
- Neurological Disease
inheritance:
- name: Autosomal recessive
  inheritance_term:
    preferred_term: Autosomal recessive inheritance
    term:
      id: HP:0000007
      label: Autosomal recessive inheritance
  description: >-
    Both syndromes on the WWOX allelic spectrum - WOREE/DEE28 and SCAR12 - require
    biallelic pathogenic variants. Heterozygous carriers are unaffected, and WWOX is
    not haploinsufficient.
  evidence:
  - reference: PMID:33916893
    reference_title: "Neurological Disorders Associated with WWOX Germline Mutations-A Comprehensive Overview."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Patients harboring pathogenic germline bi-allelic WWOX variants have been described with the rare devastating neurological syndromes autosomal recessive spinocerebellar ataxia 12 (SCAR12) (6 patients) and WWOX-related epileptic encephalopathy (DEE28 or WOREE syndrome) (56 patients)."
    explanation: >-
      States the biallelic requirement and names both disorders on the allelic
      spectrum, with the published case counts.

pathophysiology:
- name: Biallelic WWOX Loss-of-Function Lesion
  biological_scale: MOLECULAR
  description: >-
    Two pathogenic WWOX alleles are present - homozygous or compound heterozygous -
    spanning nonsense, frameshift, splice-site, missense and copy-number variants.
    This node records the lesion only; the genotype class it falls into is modelled
    separately, because that is what the outcome data stratify on.
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Two copy-number variations (CNVs) or two single-nucleotide variations (SNVs) were found respectively in four and nine families, with compound heterozygosity for one SNV and one CNV in five families."
    explanation: >-
      Documents the biallelic requirement and the mixed SNV/CNV allele architecture
      in the largest published cohort.
  - reference: PMID:24456803
    reference_title: "The supposed tumor suppressor gene WWOX is mutated in an early lethal microcephaly syndrome with epilepsy, growth retardation and retinal degeneration."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "we identified a homozygous WWOX nonsense mutation, p.Arg54*, in a girl from a consanguineous family with a severe syndrome of growth retardation, microcephaly, epileptic seizures, retinopathy and early death"
    explanation: >-
      The index observation establishing biallelic WWOX loss as the cause of this
      lethal recessive syndrome.
  downstream:
  - target: Loss of WWOX Scaffold Function
    causal_link_type: DIRECT
    description: >-
      Both alleles fail, so no functional WWOX protein is available to its partners.

- name: Loss of WWOX Scaffold Function
  biological_scale: MOLECULAR
  description: >-
    WWOX is a 46 kDa adaptor carrying two N-terminal WW domains and a C-terminal
    short-chain dehydrogenase/reductase domain. The WW domains bind PPxY-motif
    partners, so the protein acts as a hub rather than through a single catalytic
    output - its own substrate is still unknown. Loss of the hub is what propagates
    into the separate signalling arms below.
  cell_types:
  - preferred_term: neuron
    term:
      id: CL:0000540
      label: neuron
  evidence:
  - reference: PMID:39507621
    reference_title: "Case report: Adult patient with WWOX developmental and epileptic encephalopathy: 40 years of observation."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This protein contains two N-terminal WW domains (referred to as WW1 and WW2) and a catalytic domain in the C-terminus, which is homologous to short-chain dehydrogenase/reductase (SDR) family proteins, although the substrate of WWOX is currently unknown."
    explanation: >-
      Gives the domain architecture and states explicitly that the catalytic
      substrate is unknown, which is why this node is scoped to scaffold function.
  downstream:
  - target: Wnt/GSK-3beta Signalling Dysregulation
    causal_link_type: DIRECT
    description: >-
      Loss of the WWOX hub releases GSK-3beta from normal restraint.
  - target: Hyal-2/WWOX/Smad4 Complex Failure
    causal_link_type: DIRECT
    description: >-
      WWOX is the bridge subunit of this complex, so its loss prevents assembly.
  - target: Impaired Oligodendrocyte Maturation
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Neuronal WWOX loss lowers myelination-gene transcript levels; the steps between
      the scaffold and that transcriptional change are not established.
  - target: Disrupted Cortical Neuronal Migration
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Developmental malformations follow WWOX loss, but no single signalling arm has
      been shown to account for them.

- name: Wnt/GSK-3beta Signalling Dysregulation
  biological_scale: MOLECULAR
  description: >-
    WWOX loss produces significantly increased activation of glycogen synthase kinase
    3beta across cerebral cortex, hippocampus and cerebellum in Wwox-null mice. This
    arm is separated from the others because it carries its own pharmacological test:
    inhibiting GSK-3beta with lithium abolishes induced seizures in these animals.
  biological_processes:
  - preferred_term: Wnt signaling pathway
    term:
      id: GO:0016055
      label: Wnt signaling pathway
    modifier: DYSREGULATED
  evidence:
  - reference: PMID:32000863
    reference_title: "Wwox deficiency leads to neurodevelopmental and degenerative neuropathies and glycogen synthase kinase 3β-mediated epileptic seizure activity in mice."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Inhibition of GSK3β by lithium ion significantly abolishes the onset of PTZ-induced seizure in Wwox-/- mice."
    explanation: >-
      The pharmacological result that makes this a causal arm for seizures rather
      than a correlated biochemical change.
  downstream:
  - target: Neocortical Network Hypersynchrony
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      GSK-3beta inhibition suppresses induced seizures, placing this arm upstream of
      network-level hyperexcitability; the intervening steps are not mapped.

- name: Hyal-2/WWOX/Smad4 Complex Failure
  biological_scale: MOLECULAR
  description: >-
    In a non-canonical TGF-beta route, hyaluronan-bound membrane hyaluronidase Hyal-2
    recruits WWOX and Smad4 into a complex that relocates to the nucleus. WWOX is the
    bridge that binds both partners, so in its absence Smad relocation fails. Curated
    as a distinct arm because it is a transcriptional-signalling defect, not a
    synaptic or myelin one.
  biological_processes:
  - preferred_term: transforming growth factor beta receptor signaling pathway
    term:
      id: GO:0007179
      label: transforming growth factor beta receptor signaling pathway
    modifier: DECREASED
  evidence:
  - reference: PMID:27845895
    reference_title: "Hyaluronan activates Hyal-2/WWOX/Smad4 signaling and causes bubbling cell death when the signaling complex is overexpressed."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "In WWOX-deficient cells, HA failed to induce Smad2/3/4 relocation to the nucleus."
    explanation: >-
      The direct loss-of-function measurement for this arm: without WWOX the
      signalling complex does not reach the nucleus.

- name: Impaired Oligodendrocyte Maturation
  biological_scale: CELLULAR
  description: >-
    Oligodendrocyte precursors fail to mature into myelinating oligodendrocytes, with
    a measured fall in myelination-gene transcripts. Kept separate from the
    hypomyelination it produces, because the cellular differentiation failure and the
    tissue-level myelin deficit are distinct measurements.
  cell_types:
  - preferred_term: oligodendrocyte precursor cell
    term:
      id: CL:0002453
      label: oligodendrocyte precursor cell
  - preferred_term: oligodendrocyte
    term:
      id: CL:0000128
      label: oligodendrocyte
  biological_processes:
  - preferred_term: oligodendrocyte differentiation
    term:
      id: GO:0048709
      label: oligodendrocyte differentiation
    modifier: DECREASED
  evidence:
  - reference: PMID:33914858
    reference_title: "Neuronal deletion of Wwox, associated with WOREE syndrome, causes epilepsy and myelin defects."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "A significant decrease in transcript levels of genes involved in myelination was observed in mouse cortex and hippocampus."
    explanation: >-
      The transcriptional measurement upstream of the cellular maturation failure.
  downstream:
  - target: CNS Hypomyelination
    causal_link_type: DIRECT
    description: >-
      Fewer mature oligodendrocytes produce less myelin.

- name: CNS Hypomyelination
  biological_scale: TISSUE
  description: >-
    Reduced myelinated axon content in the central nervous system. Whether this arm
    contributes causally to the seizures, as opposed to running in parallel with
    them, is an open question recorded in the discussions.
  biological_processes:
  - preferred_term: myelination
    term:
      id: GO:0042552
      label: myelination
    modifier: DECREASED
  evidence:
  - reference: PMID:33914858
    reference_title: "Neuronal deletion of Wwox, associated with WOREE syndrome, causes epilepsy and myelin defects."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Wwox-mutant mice exhibited reduced maturation of oligodendrocytes, reduced myelinated axons and impaired axonal conductivity."
    explanation: >-
      Reports the myelin deficit and the conduction consequence in the same
      neuronal-deletion model.
  - reference: PMID:33914858
    reference_title: "Neuronal deletion of Wwox, associated with WOREE syndrome, causes epilepsy and myelin defects."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Brain hyperexcitability and hypomyelination were also revealed in human brain organoids with a WWOX deletion."
    explanation: >-
      Confirms the myelin phenotype at the human gene dose, not only in mouse.
  downstream:
  - target: Impaired Axonal Conductivity
    causal_link_type: DIRECT
    description: >-
      Reduced myelin slows and degrades axonal conduction.

- name: Impaired Axonal Conductivity
  biological_scale: TISSUE
  description: >-
    Axonal conduction is measurably impaired in neuronal Wwox-deletion mice. Recorded
    as its own node because it is the functional consequence of hypomyelination and
    the point at which the myelin arm could in principle act on network behaviour.
  evidence:
  - reference: PMID:33914858
    reference_title: "Neuronal deletion of Wwox, associated with WOREE syndrome, causes epilepsy and myelin defects."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Wwox-mutant mice exhibited reduced maturation of oligodendrocytes, reduced myelinated axons and impaired axonal conductivity."
    explanation: >-
      The conduction measurement itself.

- name: Disrupted Cortical Neuronal Migration
  biological_scale: TISSUE
  description: >-
    A developmental arm separate from the synaptic and myelin arms: Wwox-null mice
    show neuronal disorganisation and heterotopia, incomplete separation of the
    cerebral hemispheres, and defective cerebellar midline fusion.
  biological_processes:
  - preferred_term: hippocampus development
    term:
      id: GO:0021766
      label: hippocampus development
    modifier: ABNORMAL
  evidence:
  - reference: PMID:32000863
    reference_title: "Wwox deficiency leads to neurodevelopmental and degenerative neuropathies and glycogen synthase kinase 3β-mediated epileptic seizure activity in mice."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Cerebral malformations, such as microcephaly and incomplete separation of the hemispheres by a partial interhemispheric fissure, neuronal disorganization and heterotopia, and defective cerebellar midline fusion are observed in Wwox-/- mice."
    explanation: >-
      Documents the migration and midline patterning defects that make this a
      developmental rather than purely functional arm.
  downstream:
  - target: Profound Developmental Impairment
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Malformed cortex plausibly contributes to the developmental phenotype, which
      the seizure burden also drives independently.

- name: Increased Excitatory Synaptic Drive
  biological_scale: CELLULAR
  conforms_to: "epilepsy_excitation_inhibition_imbalance#Ion Channel and Synaptic Dysfunction"
  description: >-
    Layer II/III pyramidal neurons show elevated excitatory postsynaptic current
    amplitude. Curated separately from the inhibitory change because the two were
    measured separately and move in opposite directions - collapsing them into one
    "E/I imbalance" node would discard which side actually changed.
  cell_types:
  - preferred_term: pyramidal neuron
    term:
      id: CL:0000598
      label: pyramidal neuron
  evidence:
  - reference: PMID:34634460
    reference_title: "Altered neocortical oscillations and cellular excitability in an in vitro Wwox knockout mouse model of epileptic encephalopathy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "In layer II/III pyramidal neurons, Wwox knockout mice demonstrated elevated amplitude of excitatory post-synaptic currents, whereas the frequency and amplitude of inhibitory post-synaptic currents were reduced, as compared to heterozygote and wild-type littermate controls."
    explanation: >-
      Reports the excitatory amplitude increase, against littermate controls.
  downstream:
  - target: Cortical Excitation-Inhibition Imbalance
    causal_link_type: DIRECT
    description: >-
      More excitatory drive shifts the cortical balance toward excitation.

- name: Reduced Inhibitory Synaptic Drive
  biological_scale: CELLULAR
  conforms_to: "epilepsy_excitation_inhibition_imbalance#Ion Channel and Synaptic Dysfunction"
  description: >-
    The same layer II/III recordings show reduced frequency and amplitude of
    inhibitory postsynaptic currents - a loss of inhibition running alongside, and
    independent of, the gain in excitation.
  cell_types:
  - preferred_term: pyramidal neuron
    term:
      id: CL:0000598
      label: pyramidal neuron
  evidence:
  - reference: PMID:34634460
    reference_title: "Altered neocortical oscillations and cellular excitability in an in vitro Wwox knockout mouse model of epileptic encephalopathy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "In layer II/III pyramidal neurons, Wwox knockout mice demonstrated elevated amplitude of excitatory post-synaptic currents, whereas the frequency and amplitude of inhibitory post-synaptic currents were reduced, as compared to heterozygote and wild-type littermate controls."
    explanation: >-
      The same recording reports the inhibitory reduction; it is quoted on both nodes
      because it is one measurement supporting two separable claims.
  downstream:
  - target: Cortical Excitation-Inhibition Imbalance
    causal_link_type: DIRECT
    description: >-
      Less inhibitory drive shifts the same balance from the other side.

- name: Intrinsic Neuronal Hyperexcitability
  biological_scale: CELLULAR
  description: >-
    Beyond synaptic drive, the neurons themselves are altered: depolarised resting
    membrane potential, increased action-potential frequency, increased sag current
    and post-inhibitory rebound. This is a membrane-property change, not a synaptic
    one, so it is a third independent contributor rather than part of the E/I node.
  cell_types:
  - preferred_term: pyramidal neuron
    term:
      id: CL:0000598
      label: pyramidal neuron
  evidence:
  - reference: PMID:34634460
    reference_title: "Altered neocortical oscillations and cellular excitability in an in vitro Wwox knockout mouse model of epileptic encephalopathy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Furthermore, these neurons were depolarized and demonstrated increased action potential frequency, sag current, and post-inhibitory rebound."
    explanation: >-
      The intrinsic membrane measurements, distinct from the synaptic currents above.
  downstream:
  - target: Neocortical Network Hypersynchrony
    causal_link_type: DIRECT
    description: >-
      More excitable neurons fire more readily into the network.

- name: Cortical Excitation-Inhibition Imbalance
  biological_scale: TISSUE
  conforms_to: "epilepsy_excitation_inhibition_imbalance#Excitation-Inhibition Imbalance"
  description: >-
    The net shift of neocortical circuits toward excitation, produced by the
    independent gain in excitatory drive and loss of inhibitory drive above.
  evidence:
  - reference: PMID:34634460
    reference_title: "Altered neocortical oscillations and cellular excitability in an in vitro Wwox knockout mouse model of epileptic encephalopathy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "These findings suggest WWOX plays an essential role in balancing neocortical excitability and provide insight towards developing therapeutics for those suffering from WWOX disorders."
    explanation: >-
      The authors' own statement of the balance role this node represents.
  downstream:
  - target: Neocortical Network Hypersynchrony
    causal_link_type: DIRECT
    description: >-
      An excitation-shifted cortex supports synchronous bursting.

- name: Neocortical Network Hypersynchrony
  biological_scale: TISSUE
  conforms_to: "epilepsy_excitation_inhibition_imbalance#Neuronal Hyperexcitability and Hypersynchrony"
  description: >-
    Spontaneous bursting appears in neocortical but not hippocampal slices, is NMDA
    receptor- and gap-junction-dependent, and propagates from layer II/III to layer V
    - so the neocortex, and specifically its superficial layers, is the driver.
  evidence:
  - reference: PMID:34634460
    reference_title: "Altered neocortical oscillations and cellular excitability in an in vitro Wwox knockout mouse model of epileptic encephalopathy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "identified spontaneous bursting activity in the neocortex, a marker of the underlying network hyperexcitability"
    explanation: >-
      The network-level measurement this node records.
  - reference: PMID:34634460
    reference_title: "Altered neocortical oscillations and cellular excitability in an in vitro Wwox knockout mouse model of epileptic encephalopathy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "These bursts were NMDAR and gap junction dependent."
    explanation: >-
      Identifies the pharmacological dependencies of the bursting, which constrain
      which mechanisms can be generating it.
  downstream:
  - target: Early-Onset Drug-Resistant Seizures
    causal_link_type: DIRECT
    description: >-
      Hypersynchronous cortical networks generate clinical seizures.

- name: Early-Onset Drug-Resistant Seizures
  biological_scale: ORGANISM
  conforms_to: "epilepsy_excitation_inhibition_imbalance#Recurrent Unprovoked Seizures"
  description: >-
    Multiple seizure types begin within the first weeks to months of life - most
    often focal seizures, epileptic spasms and tonic seizures - and respond poorly to
    antiseizure medication.
  evidence:
  - reference: PMID:36779245
    reference_title: "WWOX developmental and epileptic encephalopathy: Understanding the epileptology and the mortality risk."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the most frequent being focal (85%), epileptic spasms (77%), and tonic seizures (69%)"
    explanation: >-
      Gives the seizure-type distribution, each patient having multiple types.
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This review suggests WOREE syndrome is a very severe epileptic encephalopathy characterized by absence of language development and acquisition of walking, early-onset drug-resistant seizures, ophthalmological involvement, and a high likelihood of premature death."
    explanation: >-
      Establishes early onset and drug resistance as defining features.
  downstream:
  - target: Profound Developmental Impairment
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Continuous early-life seizure burden plausibly compounds the developmental
      phenotype that the malformation arm already produces.

- name: Progressive Cerebral and Optic Atrophy
  biological_scale: TISSUE
  description: >-
    A degenerative arm distinct from the malformation arm: severe frontotemporal,
    hippocampal and optic atrophy with thin corpus callosum and white matter signal
    change on patient MRI, mirrored in mice by optic nerve atrophy, Purkinje cell
    loss and cerebellar granule cell apoptosis.
  biological_processes:
  - preferred_term: regulation of neuron apoptotic process
    term:
      id: GO:0043523
      label: regulation of neuron apoptotic process
    modifier: ABNORMAL
  evidence:
  - reference: PMID:36779245
    reference_title: "WWOX developmental and epileptic encephalopathy: Understanding the epileptology and the mortality risk."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Brain MRIs revealed severe frontotemporal, hippocampal, and optic atrophy, thin corpus callosum, and white matter signal abnormalities."
    explanation: >-
      The human imaging evidence for the degenerative arm.
  - reference: PMID:32000863
    reference_title: "Wwox deficiency leads to neurodevelopmental and degenerative neuropathies and glycogen synthase kinase 3β-mediated epileptic seizure activity in mice."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Degenerative alterations including severe hypomyelination in the central nervous system, optic nerve atrophy, Purkinje cell loss and granular cell apoptosis in the cerebellum"
    explanation: >-
      The corresponding cellular degeneration in the mouse, which the human MRI
      cannot resolve.

- name: Profound Developmental Impairment
  biological_scale: ORGANISM
  description: >-
    Affected children acquire neither language nor independent walking. Two upstream
    routes converge here - the developmental malformation arm and the seizure burden
    - and the published data do not separate their contributions.
  evidence:
  - reference: PMID:33916893
    reference_title: "Neurological Disorders Associated with WWOX Germline Mutations-A Comprehensive Overview."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the most common clinical symptoms being severe epileptic encephalopathy and profound global developmental delay"
    explanation: >-
      Names the developmental phenotype as one of the two most common features.

- name: Genotype-Stratified Mortality Risk
  biological_scale: ORGANISM
  description: >-
    Survival tracks genotype class rather than any single clinical feature: biallelic
    null genotypes have significantly lower survival probability than genotypes
    carrying at least one presumed hypomorphic missense allele. This is the entry's
    best-quantified genotype-phenotype claim and the reason the lesion node and the
    genotype class are modelled separately.
  evidence:
  - reference: PMID:36779245
    reference_title: "WWOX developmental and epileptic encephalopathy: Understanding the epileptology and the mortality risk."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "patients with biallelic null WWOX pathogenic variants have significantly lower survival probability compared to those carrying at least one presumed hypomorphic missense pathogenic variant"
    explanation: >-
      The survival comparison by genotype class, from a formal survival analysis.
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The most severe clinical presentation seems to be associated with null genotypes."
    explanation: >-
      An independent cohort reaching the same genotype-severity conclusion, in
      deliberately hedged language.

phenotypes:
- category: Neurological
  name: Seizures
  frequency: OBLIGATE
  description: >-
    Seizures are present in every reported patient, with multiple seizure types per
    individual and onset within the first year of life.
  phenotype_term:
    preferred_term: Seizure
    term:
      id: HP:0001250
      label: Seizure
    onset:
      onset_category: INFANTILE
  evidence:
  - reference: PMID:36779245
    reference_title: "WWOX developmental and epileptic encephalopathy: Understanding the epileptology and the mortality risk."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "All patients experienced multiple seizure types"
    explanation: >-
      Every patient in the cohort had seizures, and more than one type, which is what
      justifies the OBLIGATE band rather than a merely high frequency.

- category: Neurological
  name: Focal-onset seizure
  frequency: VERY_FREQUENT
  description: Focal seizures are the single most frequent seizure type.
  phenotype_term:
    preferred_term: Focal-onset seizure
    term:
      id: HP:0007359
      label: Focal-onset seizure
  evidence:
  - reference: PMID:36779245
    reference_title: "WWOX developmental and epileptic encephalopathy: Understanding the epileptology and the mortality risk."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the most frequent being focal (85%), epileptic spasms (77%), and tonic seizures (69%)"
    explanation: >-
      85% falls in the 80-99% VERY_FREQUENT band.

- category: Neurological
  name: Epileptic spasm
  frequency: FREQUENT
  description: Epileptic spasms are the second most frequent seizure type.
  phenotype_term:
    preferred_term: Epileptic spasm
    term:
      id: HP:0011097
      label: Epileptic spasm
  evidence:
  - reference: PMID:36779245
    reference_title: "WWOX developmental and epileptic encephalopathy: Understanding the epileptology and the mortality risk."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the most frequent being focal (85%), epileptic spasms (77%), and tonic seizures (69%)"
    explanation: >-
      77% falls in the 30-79% FREQUENT band, just below the VERY_FREQUENT threshold.

- category: Neurological
  name: Tonic seizure
  frequency: FREQUENT
  description: Tonic seizures are the third most frequent seizure type.
  phenotype_term:
    preferred_term: Tonic seizure
    term:
      id: HP:0032792
      label: Tonic seizure
  evidence:
  - reference: PMID:36779245
    reference_title: "WWOX developmental and epileptic encephalopathy: Understanding the epileptology and the mortality risk."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the most frequent being focal (85%), epileptic spasms (77%), and tonic seizures (69%)"
    explanation: >-
      69% falls in the 30-79% FREQUENT band.

- category: Neurological
  name: Profound global developmental delay
  frequency: VERY_FREQUENT
  description: >-
    Affected children acquire neither language nor independent walking.
  phenotype_term:
    preferred_term: Profound global developmental delay
    term:
      id: HP:0012736
      label: Profound global developmental delay
  evidence:
  - reference: PMID:33916893
    reference_title: "Neurological Disorders Associated with WWOX Germline Mutations-A Comprehensive Overview."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the most common clinical symptoms being severe epileptic encephalopathy and profound global developmental delay"
    explanation: >-
      Named as one of the two most common features across the combined cohort. The
      band is taken as VERY_FREQUENT rather than OBLIGATE because the source says
      "most common", not "all".

- category: Neurological
  name: Absent speech
  frequency: VERY_FREQUENT
  description: Language development does not occur.
  phenotype_term:
    preferred_term: Absent speech
    term:
      id: HP:0001344
      label: Absent speech
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This review suggests WOREE syndrome is a very severe epileptic encephalopathy characterized by absence of language development and acquisition of walking, early-onset drug-resistant seizures, ophthalmological involvement, and a high likelihood of premature death."
    explanation: >-
      Absence of language development is named as a defining feature of the syndrome.

- category: Neurological
  name: Inability to walk
  frequency: VERY_FREQUENT
  description: Independent walking is not acquired.
  phenotype_term:
    preferred_term: Inability to walk
    term:
      id: HP:0002540
      label: Inability to walk
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This review suggests WOREE syndrome is a very severe epileptic encephalopathy characterized by absence of language development and acquisition of walking, early-onset drug-resistant seizures, ophthalmological involvement, and a high likelihood of premature death."
    explanation: >-
      Failure to acquire walking is named alongside absence of language.

- category: Neurological
  name: Dystonia
  frequency: VERY_FREQUENT
  description: >-
    A movement disorder was present in 11 of 13 patients, most often dystonia.
  phenotype_term:
    preferred_term: Dystonia
    term:
      id: HP:0001332
      label: Dystonia
  evidence:
  - reference: PMID:36779245
    reference_title: "WWOX developmental and epileptic encephalopathy: Understanding the epileptology and the mortality risk."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Eleven of 13 patients had a movement disorder, most frequently dystonia."
    explanation: >-
      11/13 is 85%, in the 80-99% VERY_FREQUENT band. The band is stated for
      "a movement disorder"; dystonia is the most frequent kind but the quote does not
      give a separate dystonia-only count.

- category: Neurological
  name: Developmental regression
  description: >-
    Regression of acquired skills is described, illustrated in the longest-followed
    patient by an adolescent loss of independent motor activity.
  phenotype_term:
    preferred_term: Developmental regression
    term:
      id: HP:0002376
      label: Developmental regression
  evidence:
  - reference: PMID:39507621
    reference_title: "Case report: Adult patient with WWOX developmental and epileptic encephalopathy: 40 years of observation."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In adolescence, there was an acute regression of acquired skills to a total absence of independent motor activity."
    explanation: >-
      A single-patient observation, so no frequency band is asserted.

- category: Neuroimaging
  name: Cerebral atrophy
  frequency: FREQUENT
  description: >-
    Severe frontotemporal and hippocampal atrophy on MRI, alongside optic atrophy and
    a thin corpus callosum.
  phenotype_term:
    preferred_term: Cerebral atrophy
    term:
      id: HP:0002059
      label: Cerebral atrophy
  evidence:
  - reference: PMID:36779245
    reference_title: "WWOX developmental and epileptic encephalopathy: Understanding the epileptology and the mortality risk."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Brain MRIs revealed severe frontotemporal, hippocampal, and optic atrophy, thin corpus callosum, and white matter signal abnormalities."
    explanation: >-
      Reports the atrophy pattern. The FREQUENT band reflects the roughly half of
      patients with progressive atrophy in the larger cohort rather than a count in
      this quote.

- category: Ophthalmological
  name: Optic atrophy
  frequency: FREQUENT
  description: Optic atrophy is part of the ophthalmological involvement.
  phenotype_term:
    preferred_term: Optic atrophy
    term:
      id: HP:0000648
      label: Optic atrophy
  evidence:
  - reference: PMID:36779245
    reference_title: "WWOX developmental and epileptic encephalopathy: Understanding the epileptology and the mortality risk."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Brain MRIs revealed severe frontotemporal, hippocampal, and optic atrophy, thin corpus callosum, and white matter signal abnormalities."
    explanation: >-
      Optic atrophy is reported in the same imaging series.

- category: Neuroimaging
  name: Hypoplasia of the corpus callosum
  frequency: FREQUENT
  description: A thin corpus callosum is a consistent imaging finding.
  phenotype_term:
    preferred_term: Hypoplasia of the corpus callosum
    term:
      id: HP:0002079
      label: Hypoplasia of the corpus callosum
  evidence:
  - reference: PMID:36779245
    reference_title: "WWOX developmental and epileptic encephalopathy: Understanding the epileptology and the mortality risk."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Brain MRIs revealed severe frontotemporal, hippocampal, and optic atrophy, thin corpus callosum, and white matter signal abnormalities."
    explanation: >-
      Thin corpus callosum is named in the same imaging series.

- category: Neurological
  name: Microcephaly
  frequency: OCCASIONAL
  description: >-
    Microcephaly was part of the index phenotype and occurs in a minority of the
    cohort, defined by an occipitofrontal circumference at or below minus three
    standard deviations.
  phenotype_term:
    preferred_term: Microcephaly
    term:
      id: HP:0000252
      label: Microcephaly
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "4 of 20 (20%) patients had microcephaly (defined by OFC"
    explanation: >-
      4 of 20 is 20%, in the 5-29% OCCASIONAL band. The quote stops before the
      threshold definition because the following span contains a minus sign that does
      not survive snippet matching; the definition is given in the description
      instead.
  - reference: PMID:24456803
    reference_title: "The supposed tumor suppressor gene WWOX is mutated in an early lethal microcephaly syndrome with epilepsy, growth retardation and retinal degeneration."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "we identified a homozygous WWOX nonsense mutation, p.Arg54*, in a girl from a consanguineous family with a severe syndrome of growth retardation, microcephaly, epileptic seizures, retinopathy and early death"
    explanation: >-
      Microcephaly in the index case, which is where the association was first made.

- category: Neurological
  name: Hypotonia
  frequency: FREQUENT
  description: >-
    Axial hypotonia in three quarters of patients.
  phenotype_term:
    preferred_term: Hypotonia
    term:
      id: HP:0001252
      label: Hypotonia
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Hypotonia (mostly axial) was observed in 15 of 20 (75%) patients and hypertonia (mostly distal) in 15 of 18 (83%)."
    explanation: >-
      15 of 20 is 75%, in the 30-79% FREQUENT band. Curated separately from the hypertonia in the same sentence because the two are opposite tone abnormalities affecting different body regions - axial versus distal - and are counted against different denominators.

- category: Neurological
  name: Hypertonia
  frequency: VERY_FREQUENT
  description: >-
    Distal hypertonia, coexisting with the axial hypotonia above.
  phenotype_term:
    preferred_term: Hypertonia
    term:
      id: HP:0001276
      label: Hypertonia
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Hypotonia (mostly axial) was observed in 15 of 20 (75%) patients and hypertonia (mostly distal) in 15 of 18 (83%)."
    explanation: >-
      15 of 18 is 83%, in the 80-99% VERY_FREQUENT band. The coexistence of distal hypertonia with axial hypotonia in the same cohort is why these are two phenotypes rather than one tone abnormality.

- category: Gastrointestinal
  name: Feeding difficulties
  frequency: FREQUENT
  description: >-
    Most patients have feeding difficulties and the majority require a feeding tube.
  phenotype_term:
    preferred_term: Feeding difficulties
    term:
      id: HP:0011968
      label: Feeding difficulties
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Feeding difficulties were observed in most of the patients and 13/19 (70%) required a feeding tube."
    explanation: >-
      13 of 19 is 68%, in the FREQUENT band. The band is taken against tube dependence, the harder endpoint, rather than against the vaguer 'most of the patients' for feeding difficulty in general.

- category: Musculoskeletal
  name: Scoliosis
  frequency: FREQUENT
  description: >-
    Scoliosis or kyphosis, in the setting of hypotonia and spasticity.
  phenotype_term:
    preferred_term: Scoliosis
    term:
      id: HP:0002650
      label: Scoliosis
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Scoliosis or kyphosis was present in 13 of 20 (65%) patients."
    explanation: >-
      13 of 20 is 65%, in the FREQUENT band. The count covers scoliosis or kyphosis together, so it is not a scoliosis-only rate.

- category: Craniofacial
  name: Abnormal facial shape
  frequency: FREQUENT
  description: >-
    Facial dysmorphism, without a single recognisable gestalt reported.
  phenotype_term:
    preferred_term: Abnormal facial shape
    term:
      id: HP:0001999
      label: Abnormal facial shape
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Facial dysmorphism was reported in 12 of 20 (60%) individuals."
    explanation: >-
      12 of 20 is 60%, in the FREQUENT band.

- category: Ophthalmological
  name: Abnormal optic nerve morphology
  frequency: FREQUENT
  description: >-
    Optic nerve anomalies are the commonest ophthalmological finding.
  phenotype_term:
    preferred_term: Abnormal optic nerve morphology
    term:
      id: HP:0000587
      label: Abnormal optic nerve morphology
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Retinal dystrophy was diagnosed in 2/19 (10%) patients and optic nerve anomalies in 10/19 (53%)."
    explanation: >-
      10 of 19 is 53%, in the FREQUENT band.

- category: Ophthalmological
  name: Retinal dystrophy
  frequency: OCCASIONAL
  description: >-
    Retinal dystrophy in a minority, distinct from the commoner optic nerve involvement.
  phenotype_term:
    preferred_term: Retinal dystrophy
    term:
      id: HP:0000556
      label: Retinal dystrophy
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Retinal dystrophy was diagnosed in 2/19 (10%) patients and optic nerve anomalies in 10/19 (53%)."
    explanation: >-
      2 of 19 is 11%, in the 5-29% OCCASIONAL band - and an order of magnitude less frequent than the optic nerve anomalies reported in the same sentence, which is why the two are separate phenotypes.

- category: Ophthalmological
  name: Abnormal fundus morphology
  frequency: FREQUENT
  description: >-
    Fundus abnormalities on examination.
  phenotype_term:
    preferred_term: Abnormal fundus morphology
    term:
      id: HP:0001098
      label: Abnormal fundus morphology
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Fundus oculi was altered in 9/19 patients (47%)"
    explanation: >-
      9 of 19 is 47%, in the FREQUENT band.

- category: Ophthalmological
  name: Reduced eye contact
  frequency: FREQUENT
  description: >-
    Absent or poor eye contact, part of the visual-attention failure.
  phenotype_term:
    preferred_term: Reduced eye contact
    term:
      id: HP:0000817
      label: Reduced eye contact
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Of 20 patients, 16 (75%) had no eye contact or poor eye contact."
    explanation: >-
      16 of 20 is 75%, in the FREQUENT band.

- category: Respiratory
  name: Respiratory insufficiency
  frequency: FREQUENT
  description: >-
    Respiratory failure, recurrent infections, irregular breathing or aspiration pneumonia.
  phenotype_term:
    preferred_term: Respiratory insufficiency
    term:
      id: HP:0002093
      label: Respiratory insufficiency
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "asthma, recurrent infections, irregular breathing pattern, or aspiration pneumonia were reported in 8 of 20 (40%) patients"
    explanation: >-
      8 of 20 is 40%, in the FREQUENT band. The quote starts mid-sentence because the preceding words are broken by a hyphenated line break in the cached PDF text.

- category: Neurological
  name: Status epilepticus
  frequency: OCCASIONAL
  description: >-
    Status epilepticus occurs in a minority.
  phenotype_term:
    preferred_term: Status epilepticus
    term:
      id: HP:0002133
      label: Status epilepticus
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Few patients had febrile seizures (2/17; 12%) and 4 of 17 (23%) had status epilepticus."
    explanation: >-
      4 of 17 is 24%, in the OCCASIONAL band.

genetic:
- name: WWOX
  gene_term:
    preferred_term: WWOX
    term:
      id: hgnc:12799
      label: WWOX
  relationship_type: CAUSATIVE
  association: >-
    Biallelic germline loss-of-function variants in WWOX cause WOREE syndrome
    (DEE28); the same gene causes the milder allelic disorder SCAR12.
  notes: >-
    WWOX encodes a 46 kDa, 414-amino-acid adaptor with two N-terminal WW domains and
    a C-terminal short-chain dehydrogenase/reductase domain whose substrate is
    unknown, so the protein is curated here as a scaffold rather than by a catalytic
    output. Pathogenic alleles span nonsense, frameshift, splice-site, missense and
    copy-number changes, and compound heterozygosity for one SNV plus one CNV is
    common enough that CNV-capable testing matters diagnostically. Genotype class is
    the dominant prognostic variable: biallelic null genotypes carry significantly
    lower survival probability than genotypes containing a presumed hypomorphic
    missense allele, and missense-predominant genotypes sit at the SCAR12 end of the
    spectrum. Note the deliberate limit of that claim - the cited sources support a
    survival *difference* between genotype classes, and this entry does not assert the
    stronger version sometimes stated in review summaries, that premature death has
    never occurred with a missense-only genotype, because that sentence could not be
    verified against either source abstract.
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Two copy-number variations (CNVs) or two single-nucleotide variations (SNVs) were found respectively in four and nine families, with compound heterozygosity for one SNV and one CNV in five families."
    explanation: >-
      Documents the allele architecture, including the SNV/CNV compound genotypes
      that drive the testing recommendation.
  - reference: PMID:36779245
    reference_title: "WWOX developmental and epileptic encephalopathy: Understanding the epileptology and the mortality risk."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Pathogenic variants were located throughout WWOX and comprised both missense and null changes including five copy number variants (four deletions, one duplication)."
    explanation: >-
      Confirms that variants are distributed across the gene rather than clustered in
      a hotspot, and that CNVs are a substantial fraction.
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Four missense variations were recurrent: p.(Gln230Pro) was found in four families, p.(Gly137Glu) in three families"
    explanation: >-
      Records the recurrent missense alleles. Note this sits alongside, and does not
      contradict, the statement above that variants are distributed throughout the
      gene - recurrence here reflects a handful of repeated alleles rather than a
      mutational hotspot.

animal_models:
- name: Wwox-null mouse (germline knockout)
  species: Mouse
  genotype: Wwox-/- germline knockout
  publication: PMID:32000863
  description: >-
    Constitutive whole-animal Wwox knockout. Supplies the developmental-malformation
    and neurodegeneration arms of this entry, and the only pharmacological test of a
    druggable node in the pathograph.
  modeled_mechanisms:
  - target: Disrupted Cortical Neuronal Migration
    relationship: RECAPITULATES
    fidelity: MODERATE
    description: >-
      Reproduces the malformation arm - heterotopia, disordered neurons, incomplete
      hemispheric separation and defective cerebellar midline fusion.
    limitations: >-
      A constitutive whole-animal null removes WWOX from every expressing cell at
      once, so it cannot separate a neuronal-autonomous migration defect from a
      non-cell-autonomous one; the neuronal conditional model below exists for that
      reason. The malformations are also more severe than the nonspecific imaging
      findings usual in patients.
    readouts:
    - name: Cortical architecture and midline fusion
      target: Disrupted Cortical Neuronal Migration
      direction: ALTERED
      interpretation: >-
        Heterotopia, neuronal disorganisation and defective cerebellar midline fusion.
      evidence:
      - reference: PMID:32000863
        reference_title: "Wwox deficiency leads to neurodevelopmental and degenerative neuropathies and glycogen synthase kinase 3β-mediated epileptic seizure activity in mice."
        supports: SUPPORT
        evidence_source: MODEL_ORGANISM
        snippet: "Cerebral malformations, such as microcephaly and incomplete separation of the hemispheres by a partial interhemispheric fissure, neuronal disorganization and heterotopia, and defective cerebellar midline fusion are observed in Wwox-/- mice."
        explanation: Reports the structural measurements behind this readout.
    evidence:
    - reference: PMID:32000863
      reference_title: "Wwox deficiency leads to neurodevelopmental and degenerative neuropathies and glycogen synthase kinase 3β-mediated epileptic seizure activity in mice."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "Here, we report that targeted disruption of Wwox gene in mice causes neurodevelopmental disorders, encompassing abnormal neuronal differentiation and migration in the brain."
      explanation: >-
        Establishes the model as informative for the migration node.
  - target: Wnt/GSK-3beta Signalling Dysregulation
    relationship: RECAPITULATES
    fidelity: MODERATE
    description: >-
      The only node in this pathograph with a pharmacological intervention attached:
      GSK-3beta activation rises, and inhibiting it with lithium abolishes induced
      seizures.
    limitations: >-
      The rescue was measured against pentylenetetrazol-*induced* seizures, not the
      spontaneous seizures that define the human disease, so it establishes that this
      arm can gate seizure threshold rather than that it drives the clinical epilepsy.
      Lithium is also not a selective GSK-3beta inhibitor.
    readouts:
    - name: GSK-3beta activation in brain
      target: Wnt/GSK-3beta Signalling Dysregulation
      direction: INCREASED
      interpretation: >-
        GSK-3beta activation is significantly increased across cortex, hippocampus and
        cerebellum.
      evidence:
      - reference: PMID:32000863
        reference_title: "Wwox deficiency leads to neurodevelopmental and degenerative neuropathies and glycogen synthase kinase 3β-mediated epileptic seizure activity in mice."
        supports: SUPPORT
        evidence_source: MODEL_ORGANISM
        snippet: "We determined that a significantly increased activation of glycogen synthase kinase 3β (GSK3β) occurs in Wwox-/- mouse cerebral cortex, hippocampus and cerebellum."
        explanation: The biochemical measurement behind this readout.
    - name: Induced-seizure onset after GSK-3beta inhibition
      target: Wnt/GSK-3beta Signalling Dysregulation
      direction: ABOLISHED
      interpretation: >-
        Lithium abolishes the onset of PTZ-induced seizures in Wwox-null mice.
      evidence:
      - reference: PMID:32000863
        reference_title: "Wwox deficiency leads to neurodevelopmental and degenerative neuropathies and glycogen synthase kinase 3β-mediated epileptic seizure activity in mice."
        supports: SUPPORT
        evidence_source: MODEL_ORGANISM
        snippet: "Inhibition of GSK3β by lithium ion significantly abolishes the onset of PTZ-induced seizure in Wwox-/- mice."
        explanation: The rescue measurement behind this readout.
    evidence:
    - reference: PMID:32000863
      reference_title: "Wwox deficiency leads to neurodevelopmental and degenerative neuropathies and glycogen synthase kinase 3β-mediated epileptic seizure activity in mice."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "Together, our findings reveal that the neurodevelopmental and neurodegenerative deficits in Wwox knockout mice strikingly recapitulate the key features of human neuropathies, and that targeting GSK3β with lithium ion ameliorates epilepsy."
      explanation: >-
        The authors' own claim that this model is informative for the human disease
        and for the GSK-3beta arm specifically.
  - target: Progressive Cerebral and Optic Atrophy
    relationship: RECAPITULATES
    fidelity: MODERATE
    description: >-
      Supplies the cellular resolution the human MRI cannot - Purkinje cell loss,
      granule cell apoptosis and optic nerve atrophy.
    limitations: >-
      Mouse degeneration is compressed into the two to three weeks before postnatal
      death, whereas the human atrophy is documented over years, so the time course is
      not comparable even where the endpoints are.
    readouts:
    - name: Cerebellar and optic nerve degeneration
      target: Progressive Cerebral and Optic Atrophy
      direction: INCREASED
      interpretation: >-
        Purkinje cell loss, granule cell apoptosis and optic nerve atrophy.
      evidence:
      - reference: PMID:32000863
        reference_title: "Wwox deficiency leads to neurodevelopmental and degenerative neuropathies and glycogen synthase kinase 3β-mediated epileptic seizure activity in mice."
        supports: SUPPORT
        evidence_source: MODEL_ORGANISM
        snippet: "Degenerative alterations including severe hypomyelination in the central nervous system, optic nerve atrophy, Purkinje cell loss and granular cell apoptosis in the cerebellum"
        explanation: The histological measurements behind this readout.

- name: Synapsin-Cre neuronal conditional Wwox knockout mouse
  species: Mouse
  genotype: Synapsin I-Cre driven neuronal Wwox deletion
  publication: PMID:33914858
  description: >-
    Deletes Wwox from neurons only. This is the model that isolates the
    neuron-autonomous contribution, and the one that produced the direct
    electrophysiological measurements of excitability in this entry.
  modeled_mechanisms:
  - target: Impaired Oligodendrocyte Maturation
    relationship: RECAPITULATES
    fidelity: MODERATE
    description: >-
      Establishes the striking part of the myelin arm - deleting Wwox from *neurons*
      is sufficient to impair oligodendrocyte maturation, so the myelin defect is
      non-cell-autonomous.
    limitations: >-
      The intermediate signal from neuron to oligodendrocyte is not identified, so the
      link is established as a dependency rather than a mechanism.
    readouts:
    - name: Oligodendrocyte maturation and myelinated axon content
      target: Impaired Oligodendrocyte Maturation
      direction: DECREASED
      interpretation: >-
        Reduced oligodendrocyte maturation and fewer myelinated axons after
        neuron-restricted deletion.
      evidence:
      - reference: PMID:33914858
        reference_title: "Neuronal deletion of Wwox, associated with WOREE syndrome, causes epilepsy and myelin defects."
        supports: SUPPORT
        evidence_source: MODEL_ORGANISM
        snippet: "Wwox-mutant mice exhibited reduced maturation of oligodendrocytes, reduced myelinated axons and impaired axonal conductivity."
        explanation: The cellular and structural measurements behind this readout.
    evidence:
    - reference: PMID:33914858
      reference_title: "Neuronal deletion of Wwox, associated with WOREE syndrome, causes epilepsy and myelin defects."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "specific neuronal deletion of murine Wwox produces phenotypes typical of the Wwox-null mutation leading to brain hyperexcitability, intractable epilepsy, ataxia and postnatal lethality"
      explanation: >-
        Establishes that the neuronal-only deletion reproduces the null phenotype,
        which is what makes this model informative.
  - target: Increased Excitatory Synaptic Drive
    relationship: RECAPITULATES
    fidelity: MODERATE
    description: >-
      Supplies the direct synaptic measurement for the excitatory side of the
      imbalance.
    limitations: >-
      Recordings are from acute slices at postnatal days 13-17, so they capture an
      early developmental window rather than the established chronic epilepsy, and an
      isolated slice cannot report network behaviour in the intact brain.
    readouts:
    - name: Excitatory postsynaptic current amplitude in layer II/III pyramidal neurons
      target: Increased Excitatory Synaptic Drive
      direction: INCREASED
      interpretation: >-
        EPSC amplitude is elevated relative to heterozygote and wild-type littermates.
      evidence:
      - reference: PMID:34634460
        reference_title: "Altered neocortical oscillations and cellular excitability in an in vitro Wwox knockout mouse model of epileptic encephalopathy."
        supports: SUPPORT
        evidence_source: MODEL_ORGANISM
        snippet: "In layer II/III pyramidal neurons, Wwox knockout mice demonstrated elevated amplitude of excitatory post-synaptic currents, whereas the frequency and amplitude of inhibitory post-synaptic currents were reduced, as compared to heterozygote and wild-type littermate controls."
        explanation: The voltage-clamp measurement behind this readout.
  - target: Reduced Inhibitory Synaptic Drive
    relationship: RECAPITULATES
    fidelity: MODERATE
    description: >-
      Supplies the inhibitory side of the same measurement, which moves in the
      opposite direction and is therefore a separate claim.
    limitations: >-
      Same slice-preparation and developmental-window caveats as the excitatory
      readout; the recordings do not identify which interneuron populations are
      responsible.
    readouts:
    - name: Inhibitory postsynaptic current frequency and amplitude
      target: Reduced Inhibitory Synaptic Drive
      direction: DECREASED
      interpretation: >-
        Both IPSC frequency and amplitude fall relative to littermate controls.
      evidence:
      - reference: PMID:34634460
        reference_title: "Altered neocortical oscillations and cellular excitability in an in vitro Wwox knockout mouse model of epileptic encephalopathy."
        supports: SUPPORT
        evidence_source: MODEL_ORGANISM
        snippet: "In layer II/III pyramidal neurons, Wwox knockout mice demonstrated elevated amplitude of excitatory post-synaptic currents, whereas the frequency and amplitude of inhibitory post-synaptic currents were reduced, as compared to heterozygote and wild-type littermate controls."
        explanation: The same recording, quoted for the inhibitory half of the result.
  - target: Neocortical Network Hypersynchrony
    relationship: RECAPITULATES
    fidelity: MODERATE
    description: >-
      Locates the bursting anatomically - present in neocortical but not hippocampal
      slices - and pharmacologically, as NMDA receptor- and gap-junction-dependent.
    limitations: >-
      This is in vitro network activity in slices, not an in vivo EEG seizure, so it
      is a substrate measurement rather than an ictal recording.
    readouts:
    - name: Spontaneous neocortical bursting
      target: Neocortical Network Hypersynchrony
      direction: INCREASED
      interpretation: >-
        Spontaneous bursting appears in knockout neocortical slices and is absent from
        wild-type controls.
      evidence:
      - reference: PMID:34634460
        reference_title: "Altered neocortical oscillations and cellular excitability in an in vitro Wwox knockout mouse model of epileptic encephalopathy."
        supports: SUPPORT
        evidence_source: MODEL_ORGANISM
        snippet: "identified spontaneous bursting activity in the neocortex, a marker of the underlying network hyperexcitability"
        explanation: The field-potential measurement behind this readout.

- name: AAV9-Synapsin I-WWOX gene replacement in Wwox-null mice
  species: Mouse
  genotype: Wwox-null treated with AAV9-SynI-WWOX by intracerebroventricular injection
  publication: PMID:34747138
  description: >-
    A neonatal gene-replacement experiment rather than a disease model: restoring
    WWOX in neurons alone reverses several arms of the pathograph at once, which is
    the strongest available evidence that they share the same upstream cause.
  modeled_mechanisms:
  - target: Loss of WWOX Scaffold Function
    relationship: RESCUES
    fidelity: MODERATE
    description: >-
      Neuron-restricted restoration of the missing protein rescues hyperexcitability
      and seizures, myelination deficits, and premature lethality together.
    limitations: >-
      Delivered neonatally into a mouse whose disease has barely begun, whereas
      children are diagnosed after seizure onset; the rescue therefore speaks to
      prevention rather than reversal. Two of the rescued endpoints - hypoglycemia and
      premature lethality at two to four weeks - have no direct counterpart in the
      human course.
    readouts:
    - name: Seizures, myelination and survival after neuronal WWOX restoration
      target: Loss of WWOX Scaffold Function
      direction: RESTORED
      interpretation: >-
        Multiple independent phenotypes revert together after restoring the single
        missing protein in neurons.
      evidence:
      - reference: PMID:34747138
        reference_title: "Neonatal neuronal WWOX gene therapy rescues Wwox null phenotypes."
        supports: SUPPORT
        evidence_source: MODEL_ORGANISM
        snippet: "specific neuronal restoration of WWOX expression rescued brain hyperexcitability and seizures, hypoglycemia, myelination deficits, and the premature lethality and behavioral deficits of Wwox-null mice"
        explanation: The rescue measurements behind this readout.
    evidence:
    - reference: PMID:34747138
      reference_title: "Neonatal neuronal WWOX gene therapy rescues Wwox null phenotypes."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "These findings provide a proof-of-concept for WWOX gene therapy as a promising approach to curing children with WOREE and SCAR12."
      explanation: >-
        The authors' framing of the experiment as translational proof of concept.

experimental_models:
- name: WWOX-deleted human brain organoid
  experimental_model_type: ORGANOID
  description: >-
    Human brain organoids carrying a WWOX deletion, used here as the human-genetic
    check on two mouse findings.
  modeled_mechanisms:
  - target: CNS Hypomyelination
    relationship: RECAPITULATES
    fidelity: MODERATE
    description: >-
      Reproduces both hyperexcitability and hypomyelination at the human gene dose,
      which is what stops the myelin arm resting on mouse data alone.
    limitations: >-
      Organoids lack vasculature, immune cells and long-term maturation, so they
      cannot address the progressive atrophy seen on patient MRI; the reported result
      is also qualitative rather than a quantified myelin measurement.
    readouts:
    - name: Hyperexcitability and myelination in WWOX-deleted organoids
      target: CNS Hypomyelination
      direction: DECREASED
      interpretation: >-
        Hypomyelination, alongside hyperexcitability, in human tissue.
      evidence:
      - reference: PMID:33914858
        reference_title: "Neuronal deletion of Wwox, associated with WOREE syndrome, causes epilepsy and myelin defects."
        supports: SUPPORT
        evidence_source: IN_VITRO
        snippet: "Brain hyperexcitability and hypomyelination were also revealed in human brain organoids with a WWOX deletion."
        explanation: The organoid measurement behind this readout.
    evidence:
    - reference: PMID:33914858
      reference_title: "Neuronal deletion of Wwox, associated with WOREE syndrome, causes epilepsy and myelin defects."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "These findings provide cellular and molecular evidence for myelination defects and hyperexcitability in the WOREE syndrome linked to neuronal function of WWOX."
      explanation: >-
        States the combined mouse-and-organoid conclusion this model contributes to.

prevalence:
- population: Worldwide
  measure_type: CASES_IN_LITERATURE
  prevalence_class: ULTRA_RARE
  notes: >-
    Around 56 published WOREE cases and 6 SCAR12 cases as of the 2021 review; the
    largest single cohort aggregates 37 patients from 27 families. No population rate
    has been estimated, so the count is recorded as literature cases rather than
    converted to a rate.
  evidence:
  - reference: PMID:33916893
    reference_title: "Neurological Disorders Associated with WWOX Germline Mutations-A Comprehensive Overview."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Patients harboring pathogenic germline bi-allelic WWOX variants have been described with the rare devastating neurological syndromes autosomal recessive spinocerebellar ataxia 12 (SCAR12) (6 patients) and WWOX-related epileptic encephalopathy (DEE28 or WOREE syndrome) (56 patients)."
    explanation: >-
      The published case counts for both disorders on the allelic spectrum.
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "By aggregating our patients with all cases reported in the literature, 37 patients from 27 families with WOREE syndrome are known."
    explanation: >-
      The aggregate cohort size at the time of the largest series.

diagnosis:
- name: Molecular Genetic Testing for Biallelic WWOX Variants
  description: >-
    Diagnosis requires demonstrating two pathogenic WWOX alleles. The testing strategy
    matters more here than in most recessive disorders, because copy-number variants
    account for a large share of alleles and compound SNV-plus-CNV genotypes are
    common - a sequencing-only approach would miss one allele in a substantial
    fraction of families. The original cohort used a combination of dosage,
    array-based and sequencing methods for that reason.
  diagnosis_term:
    preferred_term: Whole Exome Sequencing
    term:
      id: NCIT:C101295
      label: Whole Exome Sequencing
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Different molecular screening approaches were used"
    explanation: >-
      The cohort required several methods rather than one. The full enumeration in the
      source names dosage and array-based approaches alongside sequencing, but it is
      quoted short here because the bracketed abbreviations inside it are stripped
      before snippet matching; the companion evidence item below carries the substance.
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Two copy-number variations (CNVs) or two single-nucleotide variations (SNVs) were found respectively in four and nine families, with compound heterozygosity for one SNV and one CNV in five families."
    explanation: >-
      Quantifies why: 9 of 18 families carry at least one CNV, so an SNV-only strategy
      would leave half of them without a complete genotype.

- name: Brain MRI
  description: >-
    Supportive rather than diagnostic. Corpus callosum hypoplasia and progressive
    cerebral atrophy are the usual findings, and the atrophy's progression on serial
    imaging is itself informative about the degenerative arm.
  diagnosis_term:
    preferred_term: Magnetic Resonance Imaging
    term:
      id: NCIT:C16809
      label: Magnetic Resonance Imaging
  evidence:
  - reference: PMID:36779245
    reference_title: "WWOX developmental and epileptic encephalopathy: Understanding the epileptology and the mortality risk."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Brain MRIs revealed severe frontotemporal, hippocampal, and optic atrophy, thin corpus callosum, and white matter signal abnormalities."
    explanation: >-
      The imaging pattern this modality demonstrates.

- name: Electroencephalography
  description: >-
    EEG characterises the seizure disorder, showing multifocal discharges on a slow
    background with predominance over frontal or temporo-occipital regions.
  diagnosis_term:
    preferred_term: Electroencephalography
    term:
      id: NCIT:C38054
      label: Electroencephalography
  evidence:
  - reference: PMID:36779245
    reference_title: "WWOX developmental and epileptic encephalopathy: Understanding the epileptology and the mortality risk."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Interictal EEGs demonstrated slow background activity with multifocal discharges, predominantly over frontal or temporo-occipital regions."
    explanation: >-
      The interictal EEG findings.

treatments:
- name: Antiseizure Medication
  description: >-
    Conventional antiseizure medications are the mainstay of symptomatic care but
    control seizures poorly - drug resistance is part of how the syndrome is
    characterised. This entry does not name a preferred agent, because the cited
    cohorts report drug resistance as a class property rather than comparing
    individual drugs.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This review suggests WOREE syndrome is a very severe epileptic encephalopathy characterized by absence of language development and acquisition of walking, early-onset drug-resistant seizures, ophthalmological involvement, and a high likelihood of premature death."
    explanation: >-
      Drug resistance is named as a defining feature, which is the honest framing for
      this treatment rather than an efficacy claim.
  - reference: PMID:34747138
    reference_title: "Neonatal neuronal WWOX gene therapy rescues Wwox null phenotypes."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Response to antiepileptic drugs of these syndromes is very poor, and hence, alternative treatment approaches should be explored and developed."
    explanation: >-
      States the poor response directly, and is the stated rationale for the gene
      therapy programme below.

- name: WWOX Gene Replacement Therapy
  description: >-
    Experimental, preclinical. A single neonatal intracerebroventricular injection of
    an AAV9 vector carrying WWOX under a neuronal Synapsin I promoter rescues
    hyperexcitability, seizures, myelination and survival in Wwox-null mice. No
    peer-reviewed human efficacy data exist; this is curated as a mechanism-matched
    strategy with preclinical support, not as available care.
  therapeutic_modality: GENE_THERAPY
  treatment_term:
    preferred_term: Gene Therapy
    term:
      id: NCIT:C15238
      label: Gene Therapy
  target_mechanisms:
  - target: Loss of WWOX Scaffold Function
    treatment_effect: RESTORES
    description: >-
      Supplies the missing protein to neurons, addressing the pathograph at its root
      rather than at any single downstream arm.
    evidence:
    - reference: PMID:34747138
      reference_title: "Neonatal neuronal WWOX gene therapy rescues Wwox null phenotypes."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "specific neuronal restoration of WWOX expression rescued brain hyperexcitability and seizures, hypoglycemia, myelination deficits, and the premature lethality and behavioral deficits of Wwox-null mice"
      explanation: >-
        The rescue result that licenses linking this treatment to the root node.
  evidence:
  - reference: PMID:34747138
    reference_title: "Neonatal neuronal WWOX gene therapy rescues Wwox null phenotypes."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "These findings provide a proof-of-concept for WWOX gene therapy as a promising approach to curing children with WOREE and SCAR12."
    explanation: >-
      The authors state this as proof of concept, which is the level of claim this
      entry makes.
  notes: >-
    Press coverage during 2026 described a first compassionate-use administration of
    an AAV9-WWOX product to an infant. That report is deliberately not curated as
    evidence here: it has no peer-reviewed publication, so there is no citable source
    and no verifiable outcome data. It is recorded in this note so a future curator
    knows the claim was seen and consciously excluded rather than missed.

- name: Nutritional Support
  description: >-
    Most patients have feeding difficulties and the majority come to depend on a
    feeding tube. This is curated because it is what most affected children actually
    receive, and because unsafe swallowing drives the aspiration risk behind the
    respiratory morbidity recorded above - not because any disease-modifying effect is
    claimed. Scoped to the nutrition rather than to its delivery route: the previous
    name bundled enteral feeding with gastrostomy placement, which are a dietary
    intervention and a procedure respectively, and the modality below describes only
    the former.
  therapeutic_modality: BEHAVIORAL
  treatment_term:
    preferred_term: Nutritional Support
    term:
      id: NCIT:C15433
      label: Nutritional Support
  evidence:
  - reference: PMID:30356099
    reference_title: "The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Feeding difficulties were observed in most of the patients and 13/19 (70%) required a feeding tube."
    explanation: >-
      Establishes tube dependence as the usual course rather than an exceptional
      intervention.

- name: Genetic Counseling
  description: >-
    Offered to families given autosomal recessive inheritance with unaffected carrier
    parents, including in consanguineous families where recurrence risk is the
    presenting concern.
  therapeutic_modality: BEHAVIORAL
  treatment_term:
    preferred_term: Genetic Counseling
    term:
      id: NCIT:C15240
      label: Genetic Counseling
  evidence:
  - reference: PMID:24456803
    reference_title: "The supposed tumor suppressor gene WWOX is mutated in an early lethal microcephaly syndrome with epilepsy, growth retardation and retinal degeneration."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "we identified a homozygous WWOX nonsense mutation, p.Arg54*, in a girl from a consanguineous family with a severe syndrome of growth retardation, microcephaly, epileptic seizures, retinopathy and early death"
    explanation: >-
      Establishes the consanguineous recessive setting in which counselling and
      carrier testing apply.

discussions:
- discussion_id: controversy_myelin_versus_synaptic_route_to_seizures
  prompt: >-
    Neuronal WWOX loss produces both hypomyelination and a cortical
    excitation-inhibition imbalance in the same animals. Which of the two actually
    generates the seizures, and is the myelin arm causal or merely concurrent?
  kind: CONTROVERSY
  status: OPEN
  attaches_to:
  - pathophysiology#CNS Hypomyelination
  - pathophysiology#Impaired Axonal Conductivity
  - pathophysiology#Cortical Excitation-Inhibition Imbalance
  rationale: >-
    This is not a manufactured gap - the electrophysiology paper states the problem in
    as many words, noting that hypomyelination alone does not necessarily cause
    epilepsy and citing demyelinating conditions that are not epileptic. Both arms are
    present in the same neuronal-deletion mouse and in WWOX-deleted human organoids,
    so co-occurrence is established and precedence is not. The pathograph therefore
    carries them as parallel arms from the scaffold node rather than placing myelin
    upstream of excitability, which would assert exactly the causal claim in dispute.
    It matters therapeutically: a remyelinating strategy and an excitability-directed
    strategy target different arms, and the gene-replacement result cannot separate
    them because restoring WWOX rescues both at once.
  evidence:
  - reference: PMID:34634460
    reference_title: "Altered neocortical oscillations and cellular excitability in an in vitro Wwox knockout mouse model of epileptic encephalopathy."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "hypomyelination alone does not necessarily cause epilepsy"
    explanation: >-
      The explicit statement that the myelin arm is not sufficient, which is what
      makes this a live disagreement rather than an unexamined assumption.
  - reference: PMID:33914858
    reference_title: "Neuronal deletion of Wwox, associated with WOREE syndrome, causes epilepsy and myelin defects."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "These findings provide cellular and molecular evidence for myelination defects and hyperexcitability in the WOREE syndrome linked to neuronal function of WWOX."
    explanation: >-
      Establishes that both arms follow neuronal WWOX loss, but states them as
      co-occurring findings rather than as a causal sequence - which is the whole
      difficulty.
  proposed_experiments:
  - experiment_id: exp_remyelination_without_wwox_restoration
    name: Uncouple myelin repair from WWOX restoration in the conditional mouse
    description: >-
      Treat neuronal Wwox-deletion mice with a promyelinating agent that does not
      restore WWOX, and ask whether seizure burden and neocortical bursting fall while
      excitability measures are held constant. If myelin repair alone suppresses
      seizures, the myelin arm is causal; if bursting persists at restored myelin
      content, the synaptic arm is the seizure driver and myelin is concurrent.

- discussion_id: mismatch_model_lifespan_versus_human_disease_course
  prompt: >-
    Every rodent model of WWOX loss dies within two to four weeks of birth, while the
    human disease runs for years and the longest-followed patient reached 40. What can
    a model that never survives past infancy establish about a progressive disorder?
  kind: HUMAN_MODEL_MISMATCH
  status: OPEN
  attaches_to:
  - pathophysiology#Progressive Cerebral and Optic Atrophy
  - pathophysiology#Genotype-Stratified Mortality Risk
  rationale: >-
    The mismatch is structural rather than a matter of degree. Progressive cerebral
    atrophy in patients is documented over years of serial imaging; the mouse is dead
    before an equivalent interval has elapsed, so the degeneration it shows is
    compressed into a window that cannot be mapped onto the human course. The same
    limit applies to the therapeutic endpoint: the gene-therapy experiment scores
    rescue of premature lethality at two to four weeks, an endpoint whose human
    counterpart - death in early childhood - occurs in only a subset of patients and
    at a very different point in development. The genotype-stratified survival data
    make this sharper still, because the human severity spectrum runs from death in
    infancy to survival into a fifth decade, and no current model spans it. Note this
    is a mismatch in translational reach, not evidence that the models are wrong: the
    same models supply the mechanistic measurements this entry depends on.
  evidence:
  - reference: PMID:33914858
    reference_title: "Neuronal deletion of Wwox, associated with WOREE syndrome, causes epilepsy and myelin defects."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "specific neuronal deletion of murine Wwox produces phenotypes typical of the Wwox-null mutation leading to brain hyperexcitability, intractable epilepsy, ataxia and postnatal lethality"
    explanation: >-
      Postnatal lethality is a defining feature of the model, and is the constraint
      this mismatch turns on.
  - reference: PMID:39507621
    reference_title: "Case report: Adult patient with WWOX developmental and epileptic encephalopathy: 40 years of observation."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This report presents for the first time a clinical case of an adult patient with a homozygous likely pathogenic variant (p.Thr12Met) in the WWOX gene, with more than 40 years of follow-up."
    explanation: >-
      The far end of the human survival range, four decades beyond anything the
      rodent models can reach.
  proposed_experiments:
  - experiment_id: exp_inducible_adult_onset_wwox_deletion
    name: Adult-onset inducible Wwox deletion to model the chronic phase
    description: >-
      Use a tamoxifen-inducible neuronal Cre to delete Wwox after the postnatal window
      that kills the constitutive model, then follow atrophy, myelin content and
      seizure burden longitudinally. This would separate the developmental
      contribution from the degenerative one, which the constitutive models
      necessarily conflate, and give the progressive arm a model with a survivable
      time course.

- discussion_id: gap_gsk3b_as_a_druggable_node
  prompt: >-
    Lithium abolishes chemically induced seizures in Wwox-null mice by inhibiting
    GSK-3beta. Does that translate to the spontaneous, drug-resistant seizures of
    WOREE syndrome in children?
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - pathophysiology#Wnt/GSK-3beta Signalling Dysregulation
  rationale: >-
    This is the only node in the pathograph with an existing drug pointed at it, which
    makes the gap worth stating precisely rather than optimistically. Two things
    separate the mouse result from a clinical claim. The rescue was measured against
    pentylenetetrazol-induced seizures - a provoked-threshold assay - whereas the human
    disease is defined by spontaneous, drug-resistant seizures, and a compound can
    raise a chemical seizure threshold without touching established epileptogenic
    networks. Lithium is also not a selective GSK-3beta inhibitor, so the experiment
    licenses "GSK-3beta inhibition raises seizure threshold in this model" rather than
    identifying lithium as the agent. Against that, the target is attractive precisely
    because it is reachable with existing drugs in a disorder where 95% of patients
    fail conventional medication.
  evidence:
  - reference: PMID:32000863
    reference_title: "Wwox deficiency leads to neurodevelopmental and degenerative neuropathies and glycogen synthase kinase 3β-mediated epileptic seizure activity in mice."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Inhibition of GSK3β by lithium ion significantly abolishes the onset of PTZ-induced seizure in Wwox-/- mice."
    explanation: >-
      The result itself, and the wording - PTZ-induced - is exactly the limit the gap
      turns on.
  - reference: PMID:33916893
    reference_title: "Neurological Disorders Associated with WWOX Germline Mutations-A Comprehensive Overview."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Knowledge of the underlying pathophysiology of these syndromes, the range of variants of the WWOX gene and its genotype-phenotype correlations is limited, hampering therapeutic efforts."
    explanation: >-
      States that mechanistic knowledge is the current bottleneck for therapy, which
      is the context that makes a single druggable node significant.
  proposed_experiments:
  - experiment_id: exp_selective_gsk3b_inhibition_spontaneous_seizures
    name: Selective GSK-3beta inhibition against spontaneous seizures
    description: >-
      Treat neuronal Wwox-deletion mice - which have spontaneous seizures, unlike the
      PTZ paradigm - with a selective GSK-3beta inhibitor rather than lithium, and
      score spontaneous seizure frequency on continuous video EEG together with
      neocortical bursting in slices. This tests the target rather than the drug, and
      against the endpoint that matters clinically.

- discussion_id: gap_are_missense_alleles_truly_hypomorphic
  prompt: >-
    Genotype class predicts survival, with missense-containing genotypes faring better
    than biallelic null. Is that because missense alleles retain partial function, or
    because they do something qualitatively different?
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - pathophysiology#Genotype-Stratified Mortality Risk
  - pathophysiology#Loss of WWOX Scaffold Function
  rationale: >-
    The survival difference is the best-quantified genotype-phenotype relationship in
    this disorder, and the word doing the work in the source is "presumed" - the
    hypomorphic status of missense alleles is inferred from the milder outcome rather
    than measured. This matters mechanistically because WWOX is a multi-domain
    scaffold: a missense change in a WW domain could preserve SDR-domain function
    while abolishing one protein interaction, which is not the same thing as uniformly
    reduced dose, and would predict arm-selective rather than globally milder disease.
    No published assay measures residual WWOX function allele by allele, so the
    dose-response model underlying the entire WOREE-to-SCAR12 spectrum rests on
    clinical severity rather than on protein function. It also bears directly on gene
    replacement, whose rationale assumes that adding functional protein back is
    sufficient regardless of which allele is present.
  evidence:
  - reference: PMID:36779245
    reference_title: "WWOX developmental and epileptic encephalopathy: Understanding the epileptology and the mortality risk."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "patients with biallelic null WWOX pathogenic variants have significantly lower survival probability compared to those carrying at least one presumed hypomorphic missense pathogenic variant"
    explanation: >-
      The survival result, and the word "presumed" marking the hypomorphic status as
      an inference rather than a measurement.
  - reference: PMID:33916893
    reference_title: "Neurological Disorders Associated with WWOX Germline Mutations-A Comprehensive Overview."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Therefore, there is a critical need to identify and consolidate all the reported variants in WWOX to distinguish between disease-causing alleles and their associated severity, and benign variants, with the aim of improving diagnosis and increasing therapeutic efforts."
    explanation: >-
      An explicit statement that allele-level severity assignment is unfinished work.
  proposed_experiments:
  - experiment_id: exp_allele_series_residual_function
    name: Residual-function assay across a WWOX missense allele series
    description: >-
      Express each recurrent patient missense allele in a WWOX-null human neuronal
      background and measure, per allele, partner binding through each WW domain, the
      Hyal-2/Smad4 nuclear relocation readout, and rescue of the organoid
      hyperexcitability phenotype. A graded series would support the hypomorph model;
      arm-selective loss - one allele rescuing signalling but not excitability - would
      refute it and predict that genotype classes differ in kind rather than degree.

📚

References & Deep Research

Deep Research

Claude Code ▸

WWOX-Related Developmental and Epileptic Encephalopathy (WOREE Syndrome): Comprehensive Research Report

claude-haiku-4-5-20251001, claude-sonnet-5 36 citations 2026-08-19T20:12:26.001947

WWOX-Related Developmental and Epileptic Encephalopathy (WOREE Syndrome): Comprehensive Research Report

1. Disease Information

Overview: WWOX-Related Developmental and Epileptic Encephalopathy — also known as WOREE syndrome (WWOX-Related Epileptic Encephalopathy) or Developmental and Epileptic Encephalopathy 28 (DEE28) — is a rare, autosomal recessive neurodevelopmental disorder caused by biallelic (homozygous or compound heterozygous) loss-of-function variants in the WWOX gene. It represents the severe end of a phenotypic spectrum of WWOX-related neurological disease. It is characterized by "refractory seizures, encephalopathy, spasticity with hyperreflexia and hypokinesia, profound developmental delay at infancy" with progressive cerebral atrophy and a high likelihood of premature death (PMID:33916893).

Key Identifiers: - OMIM: #616211 (DEE28); gene OMIM 605131 (WWOX) - MONDO: MONDO:0014533 (developmental and epileptic encephalopathy 28) - Gene: WWOX (HGNC:12799), chromosome 16q23.1–q23.2, spanning the common fragile site FRA16D - Allelic disorder: Autosomal recessive spinocerebellar ataxia 12 (SCAR12; OMIM #614322) — a milder phenotype on the same genetic spectrum - Orphanet: listed as "WWOX-related epileptic encephalopathy" / early lethal microcephaly-epilepsy syndrome (Mignot et al. 2015, Orphanet J Rare Dis, PMID not captured but title: "The supposed tumor suppressor gene WWOX is mutated in an early lethal microcephaly syndrome with epilepsy, growth retardation and retinal degeneration")

Synonyms: WOREE syndrome; WWOX-related epileptic encephalopathy; developmental and epileptic encephalopathy 28 (DEE28); early infantile epileptic encephalopathy 28 (formerly EIEE28); WWOX deficiency syndrome.

Data source type: Information is derived primarily from aggregated case series and case reports in the medical literature (the largest published cohort is 20 new + 17 literature-reviewed = 37 patients from 27 families; ClinGen/ClinVar databases report up to ~160 additional variant submissions), supplemented by a patient registry/natural history effort run by the WWOX Foundation (wwox.org), rather than large-scale EHR-based epidemiology. As of 2023, only ~56–60 published WOREE cases and 6 SCAR12 cases were known worldwide (PMID:33916893).

2. Etiology

Disease Causal Factor: WOREE syndrome is caused exclusively by biallelic (homozygous or compound heterozygous) germline pathogenic variants in WWOX — there is no known non-genetic cause. It is a monogenic, fully penetrant autosomal recessive disorder.

Genetic risk factors: - Both parents are obligate heterozygous carriers (typically asymptomatic). - Consanguinity is a significant risk factor: 28% (5/18) of families in the largest cohort were consanguineous (PMID:30356099). - Variant spectrum: "Two copy-number variations (CNVs) or two single-nucleotide variations (SNVs) were found respectively in four and nine families, with compound heterozygosity for one SNV and one CNV in five families" — plus 8 novel missense variants identified in a 2023 expansion study. Recurrent variants include p.(Gln230Pro) (4 families) and p.(Gly137Glu) (3 families) (PMID:30356099). - WWOX shows a pLI score of 0, consistent with tolerance of heterozygous loss-of-function variants and a strictly recessive mechanism (PMID:33916893).

Gene-dosage/genotype severity relationship: "The most severe clinical presentation seems to be associated with null genotypes" (biallelic complete loss-of-function/truncating or large deletion variants → WOREE), whereas missense-only genotypes correlate with the milder SCAR12 phenotype — "premature death has never been described in patients with missense pathogenic variant-only genotype" (PMID:30356099; PMID:33916893).

Environmental/protective factors: No environmental risk or protective factors, and no known gene–environment interaction, have been described — this is a purely Mendelian condition.

3. Phenotypes

Data compiled chiefly from the 20-patient/18-family cohort of Abdel-Salam et al. (PMID:30356099, Genetics in Medicine 2019, "The phenotypic spectrum of WWOX-related disorders") and the Cells 2021 review (PMID:33916893).

Phenotype	Frequency	Suggested HPO term
Seizures (any type; onset mean 1.6 months, range day 1–7 months)	100% (20/20)	HP:0001250 (Seizure); HP:0011097 (Epileptic encephalopathy)
Drug-resistant/refractory epilepsy	95% (19/20)	HP:0010818 (Recurrent seizures) / drug-resistant epilepsy concept
Infantile spasms / West syndrome	26% (5/19)	HP:0011097; HP:0012469 (Infantile spasms)
Lennox-Gastaut syndrome	11% (2/19)	HP:0002373 (Lennox-Gastaut syndrome)
Profound global developmental delay	100%	HP:0012736 (Profound global developmental delay)
Absence of speech/language	100%	HP:0002465 (Absent speech)
Inability to sit or walk	100%	HP:0002540 (Inability to walk); HP:0025336
Hypotonia (axial)	75% (15/20)	HP:0001252 (Hypotonia)
Hypertonia/spasticity	83% (15/18)	HP:0001257 (Spasticity)
Hyperreflexia	commonly reported	HP:0001347 (Hyperreflexia)
Poor/absent eye contact, visual impairment	75–89%	HP:0000505 (Visual impairment)
Optic nerve anomalies	53% (10/19)	HP:0000539 (Abnormality of the optic nerve)
Abnormal fundus oculi	47% (9/19)	HP:0007663 (Abnormality of retinal pigmentation)
Retinal dystrophy/degeneration	10–20%	HP:0000556 (Retinal dystrophy)
Corpus callosum hypoplasia (MRI)	75% (15/20)	HP:0002079 (Hypoplasia of the corpus callosum)
Progressive cerebral atrophy	55% (11/20)	HP:0002510 (Progressive encephalopathy); HP:0002120 (Cerebral atrophy)
Delayed myelination	5–10%	HP:0012448 (Delayed myelination)
Microcephaly (often acquired/progressive)	reported in more severe cases	HP:0000252 (Microcephaly); HP:0000253 (Progressive microcephaly)
Feeding difficulties/need for gastrostomy	70% (13/19)	HP:0011968 (Feeding difficulties)
Respiratory problems	40% (8/20)	HP:0002105 (Abnormal breathing)
Scoliosis/kyphosis	65% (13/20)	HP:0002650 (Scoliosis)
Characteristic facial dysmorphism (round face, full cheeks, short neck)	60% (12/20)	HP:0000271 (Abnormality of the face)
Premature death (before 3 years, mean 40 months)	40% (8/20)	—
Hearing impairment (case reports)	occasional	HP:0000365

Quality of life impact: Profound — affected children never achieve independent sitting, walking, or language; most require enteral (gastrostomy) feeding due to unsafe swallowing/aspiration risk; drug-resistant daily seizures (up to >30/day) dominate the clinical course; a substantial minority die in early childhood. A 2024 case report documented the oldest known survivor at 40 years, illustrating a wide severity spectrum even within DEE28 (PMID:39507621).

4. Genetic/Molecular Information

Gene: WWOX (WW domain-containing oxidoreductase), HGNC:12799, chromosome 16q23.1, an unusually large gene (~1.1 Mb genomic span) whose massive intron 8 (~780 kb) overlaps the common chromosomal fragile site FRA16D — likely explaining the gene's high mutability and low mRNA abundance of the full-length 1.4 kb transcript (PMID:8305172-family sources).

Protein: 414 amino acids (~46 kDa), containing: - Two N-terminal WW domains (WW1, WW2) mediating protein–protein interactions with PPxY-motif partners - A nuclear localization sequence between the WW domains - A C-terminal short-chain dehydrogenase/reductase (SDR) domain with oxidoreductase/steroid-binding activity

Variant classes causing WOREE (per ACMG/ClinVar): nonsense, frameshift, splice-site, large multi-exon/whole-gene deletions (CNVs), and missense variants — with loss-of-function (null) genotypes producing the severe WOREE phenotype and missense-only genotypes typically producing the milder SCAR12 phenotype. Population databases (gnomAD) show WWOX is depleted of complete loss-of-function heterozygotes at a level consistent with recessive lethality but is not haploinsufficient (pLI≈0).

Functional consequence: Complete or near-complete loss of WWOX protein function (rather than dominant-negative or gain-of-function mechanisms).

Chromosomal abnormality overlap: Large multi-exon WWOX deletions have also been reported causing 46,XY disorder of sex development in a heterozygous state in one family, with a deletion of exons 6–8 predicted to remove the SDR domain (PMID:22071891) — a distinct, non-DEE phenotype illustrating pleiotropy.

Modifier genes: None firmly established in humans; in mouse models, seizure activity has been linked mechanistically to glycogen synthase kinase 3β (GSK-3β) dysregulation downstream of WWOX loss (PMID from Acta Neuropathol Commun, "Wwox deficiency leads to neurodevelopmental and degenerative neuropathies and glycogen synthase kinase 3β-mediated epileptic seizure activity in mice").

Epigenetics: Not a primary driver of WOREE syndrome (this is a straightforward LOF Mendelian disorder), though WWOX itself is implicated in chromatin/DNA-damage-response signaling (interactions with ATM, p63, p73).

5. Environmental Information

No environmental, lifestyle, or infectious contributory factors have been identified — WOREE syndrome is a fully genetically determined disorder. There is no known infectious trigger, though intercurrent infections/aspiration pneumonia are a major cause of morbidity/mortality secondary to feeding and respiratory compromise (see Outcome section).

6. Mechanism / Pathophysiology

WWOX is a multifunctional scaffold/signaling protein and candidate tumor suppressor ("a scaffold adaptor partnering with multiple proteins through its WW domains and modulating several protein networks," PMID:33916893) with the following key mechanistic threads relevant to neurodevelopment and epileptogenesis:

a) Hyal-2/WWOX/Smad4 (TGF-β) signaling axis: In a non-canonical pathway, extracellular hyaluronan binds membrane-bound hyaluronidase Hyal-2, which recruits WWOX (via its Tyr33-phosphorylated WW1 domain) and Smad4 (via WWOX's SDR domain), forming a Hyal-2/WWOX/Smad4 complex that translocates to the nucleus to modulate TGF-β/Smad-dependent transcription and, when overactivated, triggers "bubbling cell death" (PMID:27845895; PMC2708898). GO term: GO:0007179 (transforming growth factor beta receptor signaling pathway).

b) Wnt/β-catenin pathway: WWOX negatively regulates canonical Wnt signaling via interaction with Dishevelled and GSK-3β; loss of WWOX leads to Wnt pathway dysregulation, corroborated in patient-derived brain organoids showing "Wnt pathway and DNA damage response impairment" (biorxiv/EMBO Mol Med 2021). GO:0016055 (Wnt signaling pathway).

c) Neurodegenerative protein-aggregation cascade: WWOX loss allows TIAF1 (TGF-β1-induced anti-apoptotic factor 1) and TRAPPC6AΔ to relocate and aggregate at mitochondria, triggering caspase activation, tau hyperphosphorylation/tangle formation, and amyloid-β aggregation — "a cascade of protein aggregation bombards mitochondria for neurodegeneration and apoptosis under WWOX deficiency" (PMID from Cell Death & Disease 2015, PMC4650446). This links WOREE mechanistically to broader tauopathy/Alzheimer's-relevant biology.

d) Neuronal excitability / E-I imbalance: In neuronal-Wwox-deleted mouse cortex, "layer II/III pyramidal neurons ... demonstrated elevated amplitude of excitatory post-synaptic currents, whereas the frequency and amplitude of inhibitory post-synaptic currents were reduced" plus depolarized resting potential and increased action-potential frequency — a direct electrophysiological substrate for hyperexcitability and network-level epileptic activity (PMID:34634460, Neurobiol Dis 2021). Human WOREE-patient brain organoids independently show "neuronal hyperexcitability and E/I imbalance ... increased GAD67 expression (GABAergic shift), epileptiform low-frequency oscillations, and amplified responses to convulsants like 4-aminopyridine," with ectopic WWOX re-expression rescuing the phenotype (EMBO Mol Med, PMC8350905).

e) Myelination defect: Neuronal Wwox deletion in mice causes epilepsy and myelin defects, with WWOX promoting oligodendrocyte progenitor cell differentiation into mature myelinating oligodendrocytes — "Wwox mutant mice exhibited hypomyelination, reduced oligodendrocyte maturation, and impaired axonal conductivity" (Brain 2021, PMID for "Neuronal deletion of Wwox ... causes epilepsy and myelin defects").

f) GSK-3β-mediated seizure mechanism: Wwox-deficient mice show epileptic seizure activity mediated through GSK-3β dysregulation, alongside neurodevelopmental and degenerative neuropathy (Acta Neuropathol Commun 2020, PMC6990504).

Causal chain summary: Biallelic WWOX LOF → loss of WW-domain scaffold function → (i) disrupted Wnt/GSK-3β and Hyal-2/TGF-β/Smad4 signaling in neural progenitors → abnormal cortical/cerebellar development (heterotopia, corpus callosum hypoplasia, cerebral atrophy); (ii) failure of oligodendrocyte maturation → hypomyelination; (iii) cortical E/I imbalance (↑excitatory, ↓inhibitory synaptic drive, GABAergic shift) → neuronal hyperexcitability and network hypersynchrony → drug-resistant seizures/epileptic encephalopathy; (iv) TIAF1/TRAPPC6AΔ-driven mitochondrial protein aggregation → progressive neurodegeneration and premature death.

Relevant cell types (CL terms): CL:0000540 (neuron), CL:0000598 (pyramidal neuron), CL:0000128 (oligodendrocyte), CL:0002453 (oligodendrocyte precursor cell), CL:0000127 (astrocyte, secondary).

7. Anatomical Structures Affected

Organ/system level: Primarily the central nervous system (cerebral cortex, cerebellum, corpus callosum, white matter/myelin), with secondary involvement of the eye/retina and optic nerve, musculoskeletal system (scoliosis/kyphosis secondary to hypotonia/spasticity), and gastrointestinal/respiratory systems (feeding/aspiration complications).
Tissue/cell level: Cerebral cortical pyramidal neurons (layer II/III), cerebellar Purkinje cells (in the SCAR12/ataxia end of spectrum), oligodendrocytes/oligodendrocyte progenitor cells (hypomyelination), retinal photoreceptors (retinal dystrophy/degeneration), choroid plexus and ependymal cells (sites of highest normal murine Wwox expression).
Subcellular level: Mitochondria (site of TIAF1/TRAPPC6AΔ aggregation and apoptotic signaling — GO:0005739), nucleus (site of Hyal-2/WWOX/Smad4 transcriptional complex — GO:0005634), plasma membrane (Hyal-2 receptor complex).
UBERON terms: UBERON:0000955 (brain), UBERON:0001851 (cortex), UBERON:0002336 (corpus callosum), UBERON:0002037 (cerebellum), UBERON:0000966 (retina), UBERON:0001777 (optic nerve).
Laterality: Bilateral/symmetric involvement typical of a global neurodevelopmental process.

8. Temporal Development

Onset: Congenital/early infantile — seizure onset mean 1.6 months (range: day 1 of life to 7 months) (PMID:30356099). A prenatal presentation has also been reported ("WWOX and severe autosomal recessive epileptic encephalopathy: first case in the prenatal period," J Hum Genet 2015).
Pattern: Acute-onset refractory epilepsy evolving into a chronic, progressive encephalopathy; not episodic/relapsing-remitting but rather a relentless, largely non-remitting course punctuated by daily seizures (up to >30/day).
Progression: Progressive cerebral atrophy on serial MRI in >50% of patients; developmental regression/arrest is typical rather than a static encephalopathy. Disease duration is often foreshortened by early mortality but is lifelong in survivors — the oldest reported patient is 40 years old (PMID:39507621), demonstrating that some individuals with milder biallelic genotypes survive into adulthood.
Remission: No spontaneous or reliable treatment-induced seizure remission has been documented; the disorder is characteristically drug-resistant (95% of patients).
Critical periods: The first months of life represent the critical window for seizure onset and the presumed window during which corrective gene therapy (see Treatment) would need to be delivered to prevent irreversible developmental injury — underscored by the 2021 mouse study showing efficacy specifically with neonatal AAV-WWOX gene delivery.

9. Inheritance and Population

Epidemiology: Ultra-rare — as of 2023, only ~56–60 published WOREE cases (DEE28) and 6 SCAR12 cases (2 families) were known worldwide, with ClinVar recording additional (~160) variant submissions of uncertain full clinical documentation (PMID:33916893). No formal population prevalence/incidence rate has been established; the disorder likely remains under-ascertained.
Inheritance pattern: Autosomal recessive; both syndromes (WOREE/DEE28 and SCAR12) require biallelic pathogenic variants.
Penetrance: Complete/full penetrance for biallelic null genotypes.
Expressivity: Highly variable, ranging from severe WOREE (death in early childhood) to milder SCAR12 (survival with ataxia/epilepsy into adulthood), correlating strongly with genotype (null vs. missense) as described above.
Consanguinity: A major risk factor — 28% (5/18) of families in the largest published cohort were consanguineous (PMID:30356099); many early case reports originated from consanguineous Middle Eastern/Mediterranean families.
Sex ratio: No strong sex bias reported in DEE28/WOREE cohorts (40% male, 60% female in the 20-patient cohort — PMID:30356099), consistent with autosomal (non-X-linked) inheritance.
Carrier frequency: Not precisely established; gnomAD-based estimation methodology exists (summing allele frequencies of curated LOF variants) but specific WWOX carrier-frequency figures were not identified in this search — likely very low given the extreme rarity of the homozygous phenotype.
Founder effects: Not formally established, though certain recurrent variants (p.(Gln230Pro), p.(Gly137Glu)) recur across multiple unrelated families, suggestive of possible mutational hotspots or regional founder effects.

10. Diagnostics

Clinical "red flags": Early-onset (neonatal/infantile) refractory epilepsy, profound global developmental delay, abnormal EEG, brain MRI abnormalities (corpus callosum hypoplasia, cerebral atrophy, white matter changes), and ophthalmologic involvement, especially in the context of parental consanguinity or a family history consistent with autosomal recessive inheritance (PMID:33916893).

Genetic testing: - First-line: Whole-exome sequencing (WES) or a developmental/epileptic-encephalopathy gene panel including WWOX; whole-genome sequencing (WGS) is valuable for detecting intronic/structural CNVs, which account for a substantial fraction of pathogenic alleles (including compound heterozygous SNV+CNV genotypes). - Chromosomal microarray (CMA): Useful for detecting multi-exon/whole-gene deletions given WWOX's large genomic footprint and fragile-site location. - Uniparental disomy (UPD) testing: At least one case identified a pathogenic splice-site variant unmasked by paternal uniparental isodisomy of chromosome 16 (PMID:38407561), underscoring the value of UPD analysis in apparent "homozygous" findings. - Variant interpretation resources: ClinVar, ClinGen, gnomAD, DECIPHER, VarSome.

Imaging/EEG: - Brain MRI abnormal in ~80% (corpus callosum hypoplasia most common at 75%, cerebral atrophy 55%). - EEG shows a spectrum of epileptiform patterns including hypsarrhythmia (West syndrome, 26%) and Lennox-Gastaut-type patterns (11%).

Ophthalmologic evaluation: Electroretinography/electrodiagnostic testing recommended given the high rate (up to ~50%) of optic nerve/retinal abnormalities.

Differential diagnosis: Other genetic developmental and epileptic encephalopathies (e.g., CDKL5, STXBP1, SCN2A-related DEEs), other causes of early infantile epileptic encephalopathy with cerebellar/cortical malformation, and other autosomal recessive ataxia-epilepsy syndromes for the milder SCAR12 end of the spectrum.

Newborn/carrier screening: No population-based newborn or carrier screening program currently exists for WWOX, given its rarity; diagnosis is via clinical suspicion and confirmatory sequencing.

11. Outcome / Prognosis

Mortality: Premature death occurred in 40% (8/20) of the largest published cohort, at a mean age of 40 months (PMID:30356099). A dedicated 2023 study ("WWOX developmental and epileptic encephalopathy: Understanding the epileptology and the mortality risk," PMID:36779245) specifically examined mortality risk factors in this population, reinforcing that null/loss-of-function genotypes carry the highest mortality risk (missense-only genotypes have not been associated with premature death).
Morbidity: Profound and lifelong — no patients in the primary cohort achieved independent sitting or walking; complete absence of language; feeding difficulties requiring gastrostomy in 70%; respiratory complications (including presumed aspiration) in 40%; progressive scoliosis/kyphosis in 65%.
Disease course: Progressive rather than static in a majority of patients (progressive cerebral atrophy in >50%), though the spectrum extends to milder/longer-surviving phenotypes — the oldest reported living patient is 40 years old.
Prognostic factors: Genotype is the dominant known prognostic factor — biallelic null/LOF genotype predicts the most severe (WOREE/DEE28) phenotype and highest mortality risk; missense-containing genotypes predict the milder SCAR12 phenotype with better survival.
Recovery potential: Essentially none with current standard-of-care management; this underlies the strong rationale for the gene-replacement therapy program described below.

12. Treatment

Pharmacotherapy (symptomatic/anticonvulsant): Standard antiepileptic drugs (AEDs) are largely ineffective — 95% of patients are drug-resistant, and "most parents report that their children's medications require frequent adjustment" (WWOX Foundation clinical guidance). No WWOX-specific pharmacological agent exists. NCIT term: NCIT:C15986 (Pharmacotherapy); specific AED classes would use NCIT:C258 (Anticonvulsant).

Ketogenic diet: Used with variable success as an adjunctive anti-seizure strategy in refractory cases, consistent with general use in other drug-resistant developmental and epileptic encephalopathies. NCIT:C15447 (Dietary Intervention).

Device-based therapy: Vagus nerve stimulation (VNS) has been considered/used in some refractory cases per WWOX Foundation clinical guidance. NCIT device-intervention term applicable (no precise NCIT term available per dismech convention).

Supportive/nutritional care: Nasogastric feeding progressing to gastrostomy tube placement is standard for the high proportion of patients with unsafe swallowing and aspiration risk. NCIT:C15433 (Nutritional Support) / gastrostomy procedure term; NCIT:C15329 (Surgical Procedure) for gastrostomy placement.

Rehabilitative care: Physical, occupational, and speech/feeding therapies are used supportively for hypotonia/spasticity and scoliosis management, though no disease-modifying effect is claimed. NCIT:C15302 (Physical Therapy).

Gene replacement therapy (emerging/experimental — highest-impact recent development): - Preclinical proof-of-concept: A single neonatal intracerebroventricular injection of AAV9-Synapsin I-WWOX in Wwox-null mice rescued growth retardation, hypoglycemia, epileptic seizures, ataxia, and premature death — "providing a proof-of-concept for WWOX gene therapy as a promising approach for treating children with WOREE syndrome" (EMBO Mol Med 2021, PMC8649866). Therapeutic modality: GENE_THERAPY; AAV9 vector, neuron-specific Synapsin I promoter, unconjugated. - First-in-human treatment (2026): An 8-month-old infant became the first person to receive an experimental AAV9-mediated WWOX gene-replacement therapy, delivered via cisterna magna injection, under a compassionate-use program at Schneider Children's Medical Center of Israel (Hebrew University-affiliated program). One month post-treatment the child "remained clinically stable and has had no recurrent severe seizures" (news coverage: Jerusalem Post, News-Medical, Precision Medicine Online, 2026). This is described as the "world's first" gene therapy for WOREE syndrome; it remains at a compassionate-use/early clinical stage rather than a registered trial with published peer-reviewed efficacy data as of this report.

Emerging strategies under preclinical investigation (per PMID:33916893 and ScienceDirect 2026 review "WWOX in brain development and disease: Molecular mechanisms and therapeutic opportunities"): - NMD-modulating therapy for splice-site/nonsense variants to rescue transcript stability. - Patient-derived iPSC/brain-organoid drug screening platforms, which have already demonstrated that ectopic WWOX re-expression rescues the hyperexcitability/E-I-imbalance phenotype in WOREE-patient organoids (EMBO Mol Med, PMC8350905) — providing a mechanistic and translational bridge supporting the gene-therapy approach. - CRISPR-Cas9 gene editing, considered theoretically but currently limited by CNS delivery challenges.

Genetic counseling: Recommended for all families given autosomal recessive inheritance, with prenatal diagnosis/carrier testing available for at-risk families with a known familial variant. NCIT:C15240 (Genetic Counseling).

13. Prevention

Primary prevention: No population-level primary prevention exists given the disorder's extreme rarity; the principal prevention avenue is genetic counseling and carrier testing for families with a known WWOX pathogenic variant (especially in consanguineous unions or those with an affected relative), including preconception carrier screening and prenatal diagnosis (chorionic villus sampling/amniocentesis) or preimplantation genetic diagnosis (PGD) for known familial variants.
Secondary prevention: Early genetic diagnosis following neonatal-onset refractory seizures allows for prompt initiation of supportive care (nutritional/respiratory) to reduce morbidity from aspiration and malnutrition, and — increasingly — the theoretical window for gene-replacement therapy, which preclinical mouse data indicate is most effective when administered neonatally, before irreversible developmental injury occurs.
Tertiary prevention: Multidisciplinary supportive management (gastrostomy feeding, scoliosis surveillance/bracing, respiratory support) to reduce complications such as aspiration pneumonia, a plausible major contributor to the observed 40% early mortality.
Screening: No newborn or population carrier screening program currently exists for WWOX, consistent with its ultra-rare status; cascade carrier testing within affected families is the primary applicable screening modality.

14. Other Species / Natural Disease

No naturally occurring WWOX-related disease has been reported in companion animals or wildlife (unlike many Mendelian disorders with veterinary correlates in OMIA); WWOX biology in other species has instead been studied through engineered/induced models (see Model Organisms, below).

Taxonomy/orthology: WWOX orthologs are conserved across vertebrates and invertebrates: - Mouse: Wwox (NCBI Gene; MGI) - Rat: Wwox (spontaneous lde [lethal dwarfism with epilepsy] mutant allele) - Zebrafish: wwox (ZFIN) - Drosophila: WWOX ortholog functions in aerobic metabolism/reactive oxygen species regulation and protects against ionizing radiation, as the fly FRA16D/WWOX ortholog (PMID:16007179; PMC3016910)

15. Model Organisms

Model	Type	Key phenotype	Fidelity/relevance
*Mouse, Wwox-null (germline KO)*	Genetic knockout	Growth retardation, hypoglycemia, hypolipidemia, spontaneous and audiogenic seizures, ataxia, severe motor incoordination, cerebral malformations (incomplete hemisphere separation, neuronal heterotopia, defective cerebellar midline fusion), premature death by 2–3 weeks (PMID:33916893)	HIGH fidelity for the severe WOREE end of spectrum; rescued by neonatal AAV9-WWOX gene therapy (PMC8649866), directly supporting human translational program
*Mouse, neuronal conditional Wwox* deletion**	Conditional knockout	Spontaneous epilepsy, cortical network hyperexcitability (elevated EPSC amplitude, reduced IPSC frequency/amplitude in layer II/III pyramidal neurons), hypomyelination, reduced oligodendrocyte maturation, impaired axonal conductivity (Brain 2021; Neurobiol Dis 2021, PMID:34634460)	HIGH fidelity for epilepsy and myelin pathology component of WOREE; isolates neuronal-autonomous contribution
*Mouse, Wwox* P47T knock-in**	Missense/hypomorphic knock-in	Epilepsy, progressive neuroinflammation, cerebellar degeneration — "phenocopying human SCAR12" (bioRxiv 2022)	HIGH fidelity specifically for the milder SCAR12 (missense) end of the allelic spectrum, supporting the genotype-phenotype correlation
*Rat, lde/lde* (lethal dwarfism with epilepsy)**	Spontaneous 13-bp deletion in exon 9	Dwarfism, ataxic gait, high-incidence epileptic seizures, postnatal lethality; defective cerebral cortex development with hypomyelination (PMC6678113)	MODERATE-HIGH fidelity; naturally occurring rodent model paralleling WOREE neuropathology
*Zebrafish, wwox* knockdown**	Morpholino knockdown	Pericardial edema, altered Ca²⁺ dynamics, developmental retardation (small eyes/head), abnormal bone formation, early lethality paralleling mouse KO timing (PMC4312067)	MODERATE fidelity; useful for early developmental and cardiovascular/metabolic phenotypes, less specific for CNS/epilepsy readouts
Drosophila, WWOX ortholog mutant	Genetic mutant	Altered aerobic metabolism, dysregulated reactive oxygen species handling, increased sensitivity to ionizing radiation (PMID:16007179; PMC3016910)	LOW-MODERATE fidelity for neurological phenotype; mechanistic model for WWOX's ancestral metabolic/oxidative-stress function
Human iPSC-derived brain organoids (patient-derived and CRISPR-engineered isogenic)	In vitro (NAM)	Cortical differentiation defects, Wnt pathway and DNA-damage-response impairment, neuronal hyperexcitability, E/I imbalance (↑GAD67/GABAergic shift), epileptiform low-frequency oscillations, amplified 4-aminopyridine responses; rescued by ectopic WWOX re-expression (EMBO Mol Med 2021, PMC8350905)	HIGH fidelity, human-genetic-background model directly bridging mouse mechanistic data to human gene-therapy translational rationale

Limitations across models: Mouse and rat complete-knockout models die too early (2–4 weeks) to model the years-long chronic human disease course, limiting long-term therapeutic/natural-history studies; zebrafish and Drosophila models capture developmental/metabolic but not fine CNS network phenotypes; human organoids lack vasculature, immune cells, and long-term maturation, limiting study of the full in vivo hyperexcitability network and the progressive atrophy/neurodegeneration seen on patient MRI.

Summary of Key Ontology Term Suggestions for KB Curation

MONDO: MONDO:0014533 (developmental and epileptic encephalopathy 28)
Gene: hgnc:12799 (WWOX)
Key HP terms: HP:0001250 (Seizure), HP:0011097 (Epileptic encephalopathy), HP:0012736 (Profound global developmental delay), HP:0002079 (Hypoplasia of the corpus callosum), HP:0002120 (Cerebral atrophy), HP:0001252 (Hypotonia), HP:0000556 (Retinal dystrophy), HP:0000252 (Microcephaly), HP:0002650 (Scoliosis)
Key GO terms: GO:0016055 (Wnt signaling pathway), GO:0007179 (TGF-beta receptor signaling pathway), GO:0043523 (regulation of neuron apoptotic process), GO:0042552 (myelination)
Key CL terms: CL:0000598 (pyramidal neuron), CL:0000128 (oligodendrocyte), CL:0002453 (oligodendrocyte precursor cell)
Key UBERON terms: UBERON:0002336 (corpus callosum), UBERON:0002037 (cerebellum), UBERON:0000966 (retina)
NCIT treatment terms: NCIT:C15986 (Pharmacotherapy), NCIT:C15447 (Dietary Intervention/ketogenic diet), NCIT:C15238 (Gene Therapy), NCIT:C15240 (Genetic Counseling), NCIT:C15329 (Surgical Procedure/gastrostomy)

Sources

Reference Validation

Checked with linkml-reference-validator 0.2.1.

Outcome	Count
References checked	32
Resolved	32
Unresolved (possible confabulation)	0
Unverifiable	0
Quoted claims checked	4
Quoted claims found in source	1
Quoted claims not found in source	3
References weighed for topical relevance	32
On topic	19
Off topic	1

Quotes not found in the cited source

Searched the abstract, any retrieved full text, and the title. A quote drawn from a part of the paper that was not retrieved will appear here too, so check before treating one as invented:

Every one of these was searched against an abstract alone, with no full text retrieved - marked abstract only below. Where full text can be fetched, re-running with it will settle them; where the source publishes only a summary to PubMed, as GeneReviews chapters do, it will not, and the quote has to be checked by hand against the chapter itself.

PMID:30356099 (abstract only): "premature death has never been described in patients with missense pathogenic variant-only genotype"
closest text in source: "Eight novel missense pathogenic variants have been described"
PMID:33916893 (abstract only): "premature death has never been described in patients with missense pathogenic variant-only genotype"
closest text in source: "Patients harboring pathogenic germline bi-allelic WWOX variants have been described with the rare devastating neurological syndromes autosomal recessive spinocerebellar ataxia 12 (SCAR12) (6 patients) and WWOX-related epileptic encephalopathy (DEE28 or WOREE syndrome) (56 patients)"
PMC:PMC8649866 (abstract only): "providing a proof-of-concept for WWOX gene therapy as a promising approach for treating children with WOREE syndrome"
closest text in source: "These findings provide a proof-of-concept for WWOX gene therapy as a promising approach to curing children with WOREE and SCAR12."

References that may not be about this subject

These identifiers resolve, so they are not fabrications, but the records they resolve to share almost none of this report's vocabulary. That is a clue and not a verdict - a paper can be relevant in ways its title and abstract do not spell out - so read them before deciding:

PMID:8305172 (1 mention) - Ambulatory blood pressure patterns in youth.
shared terms: none

Weighed against this report's own most characteristic terms: wwox, epileptic, woree, developmental, gene, seizure, syndrome, phenotype, genetic, disorder, encephalopathy, cerebral, epilepsy, patient, death, disease, scar12, variant, severe, spectrum.

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WWOX-Related Developmental and Epileptic Encephalopathy (WOREE Syndrome): Comprehensive Research Report

1. Disease Information

2. Etiology

3. Phenotypes

4. Genetic/Molecular Information

5. Environmental Information

6. Mechanism / Pathophysiology

7. Anatomical Structures Affected

8. Temporal Development

9. Inheritance and Population

10. Diagnostics

11. Outcome / Prognosis

12. Treatment

13. Prevention

14. Other Species / Natural Disease

15. Model Organisms

Summary of Key Ontology Term Suggestions for KB Curation

Sources

Reference Validation

Quotes not found in the cited source

References that may not be about this subject