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Genetic Epilepsy v0.2091 PTS Zornitza Stark Marked gene: PTS as ready
Genetic Epilepsy v0.2091 PTS Zornitza Stark Gene: pts has been classified as Green List (High Evidence).
Genetic Epilepsy v0.2091 PTS Zornitza Stark Phenotypes for gene: PTS were changed from to Hyperphenylalaninemia, BH4-deficient, A, MIM# 261640
Genetic Epilepsy v0.2090 PTS Zornitza Stark Mode of inheritance for gene: PTS was changed from Unknown to BIALLELIC, autosomal or pseudoautosomal
Genetic Epilepsy v0.2089 PTS Zornitza Stark changed review comment from: Well established gene-disease association.; to: Well established gene-disease association. Seizures are part of the phenotype.
Genetic Epilepsy v0.1896 TUBGCP2 Zornitza Stark gene: TUBGCP2 was added
gene: TUBGCP2 was added to Genetic Epilepsy. Sources: Expert Review
Mode of inheritance for gene: TUBGCP2 was set to BIALLELIC, autosomal or pseudoautosomal
Publications for gene: TUBGCP2 were set to 31630790
Phenotypes for gene: TUBGCP2 were set to Pachygyria, microcephaly, developmental delay, and dysmorphic facies, with or without seizures, OMIM # 618737
Review for gene: TUBGCP2 was set to GREEN
Added comment: PMID: 31630790 (2019) - Five patients from four families with biallelic variants in the TUBGCP2 gene. Affected individuals shared phenotypic features that included progressive microcephaly (4/4), developmental delay (5/5, mild-severe), generalised seizures (4/5, onset at 6yrs-9m, 5m, and 7m). All patients exhibited lissencephaly-spectrum phenotypes with varying degrees of cortical malformations on brain imaging including pachygyria and subcortical band heterotopia.

All variants segregated with disease in each family. Analysis of fibroblasts derived from one patient with a splice site variant revealed several abnormal transcripts, predicted to result in LoF. No further functional studies of other variants or patient cells were performed.
Sources: Expert Review
Genetic Epilepsy v0.1823 TRA2B Elena Savva gene: TRA2B was added
gene: TRA2B was added to Genetic Epilepsy. Sources: Literature
Mode of inheritance for gene: TRA2B was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown
Publications for gene: TRA2B were set to PMID: 36549593
Phenotypes for gene: TRA2B were set to Neurodevelopmental disorder, TRA2B-related (MONDO#0700092)
Review for gene: TRA2B was set to GREEN
Added comment: PMID: 36549593
- 12 individuals with ID and dev delay. Additional features include infantile spams 6/12, hypotonia 12/12, dilated brain ventricles 6/12, microcephaly 5/12
- All variants result in the loss of 1/2 transcripts (start-losses or PTCs upstream of a second translation start position). Shorter transcript expression is increased, longer transcript expression is decreased.
- Apparently het mice K/O are normal, but complete K/O cannot develop embryonically.
- DN mechanism suggested
Sources: Literature
Genetic Epilepsy v0.1675 PTS Zornitza Stark Tag treatable tag was added to gene: PTS.
Genetic Epilepsy v0.1154 AP1G1 Danielle Ariti gene: AP1G1 was added
gene: AP1G1 was added to Genetic Epilepsy. Sources: Literature
Mode of inheritance for gene: AP1G1 was set to BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Publications for gene: AP1G1 were set to 34102099
Phenotypes for gene: AP1G1 were set to Neurodevelopmental disorder (NDD); Intellectual Disability; Epilepsy
Review for gene: AP1G1 was set to GREEN
Added comment: Two bi-allelic homozygous missense variants were found in two distinct families with Italian and Pakistani origins; homozygous missense variants.

Eight de novo heterozygous variants were identified in nine isolated affected individuals from nine families; including five missense, two frameshift, and one intronic variant that disrupts the canonical splice acceptor site.

Knocking out AP1G1 Zebrafish model resulted in severe developmental abnormalities and increased lethality.

All individuals had neurodevelopmental disorder (NDD) including global developmental delay and ID, which varied in severity from mild to severe.
Sources: Literature
Genetic Epilepsy v0.774 MADD Konstantinos Varvagiannis gene: MADD was added
gene: MADD was added to Genetic Epilepsy. Sources: Literature
Mode of inheritance for gene: MADD was set to BIALLELIC, autosomal or pseudoautosomal
Publications for gene: MADD were set to 28940097; 29302074; 32761064
Phenotypes for gene: MADD were set to Global developmental delay / Intellectual disability / Seizures; Global developmental delay / Intellectual disability / Seizures / Abnormality of the endocrine system / Exocrine pancreatic insufficiency / Constipation / Diarrhea / Anemia / Thrombocytopenia / Abnormality of the autonomic nervous system
Penetrance for gene: MADD were set to Complete
Review for gene: MADD was set to GREEN
Added comment: There are 3 reports on the phenotype of individuals with biallelic pathogenic MADD variants. Clinical presentation appears to be relevant for inclusion of this gene in both ID and epilepsy panels. A recent study provides extensive clinical details and suggests that the phenotype may range from DD/ID to a severe pleiotropic disorder characterized by severe DD (and ID), sensory and autonomic dysfunction, exocrine and endocrine insufficiency and haematological anomalies). Seizures have been reported in several individuals with either presentation.
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Anazi et al (2017 - PMID: 28940097) identified MADD as a potential ID gene. The authors described a girl with profound DD and seizures among other features. The child, deceased at the age of 14m, was born to consanguineous Saoudi parents and was found to harbour a homozygous missense SNV [NM_003682.3:c.2930T>G:p.(Val977Gly)]. Through GeneMatcher, the authors identified a further 6 y.o. girl, compound heterozygous for a missense and a stopgain variant [NM_003682.3:c.593G>A:p.(Arg198His) and c.979C>T:p.(Arg327*)]. The child had normal development and milestones until the age of 15m, when she demonstrated delay in speech, social interactions, poor eye contact and was later diagnosed with ASD.
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Hu et al (2019 - PMID: 29302074) provided details on a 22- and 30- y.o. female born to (reportedly) unrelated parents. Formal evaluation (WAIS-IV) suggested ID in the mild to moderate range(IQs of 50 and 60 respectively). Both were homozygous for an indel [NM_003682:c.3559del / p.(Met1187*)].
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Schneeberger et al (2020 - PMID: 32761064) report on 23 affected subjects.

The authors categorized the phenotypes in 2 groups. 9 individuals belonging to group 1 presented with hypotonia, DD (9/9) with speech impaiment, ID (5/5) and seizures (6/9). 14 patients, belonging to group 2 had DD (9/9 - severe), ID (3/3), seizures (9/14), endo- and exocrine dysfunction, impairment of sensory and autonomic nervous system, haematological anomalies. The course was fatal in some cases, within the later group. Some facial features appeared to be more frequent (e.g. full cheeks, small mouth, tented upper lip - small palpebral fissures in some, etc). Genital anomalies were also common in males from both groups.

All were found to harbor biallelic MADD variants (21 different - missense and pLoF SNVs as well as an intragenic deletion). Variants in all cases affected all 7 isoforms. Data did not allow genotype-phenotype correlations e.g. individuals with missense and a pLoF variant (in trans) were identified within either group.

Studies using patient-derived fibroblasts supported the role of the variants, e.g. lower mRNA levels for those where NMD would apply, deficiency or drastic reduction of the protein upon immunobloting (also the case for missense variants) and mRNA analyses demonstrating aberrant transcripts for 2 relevant variants.

MADD encodes the MAPK-activating protein containing a death domain implicated among others in neurotransmission (Rab3 GEF and effector playing a role in formation/trafficking of synaptic vessicles), cell survival (pro-apoptotic effects/protection against apoptosis upon TNF-a treatment), etc. The gene has relevant expression pattern in fetal and adult brain (discussed by Hu et al).

Studies in patient fibroblasts provide evidence of reduced activation of MAP kinases ERK1/2 upon treatment with TNF-a, activation of the intrinsic (TNF-a-dependent-) apoptosis. MADD deficiency was shown to result to decreased EGF endocytosis (likely mediated by Rab3).

Mouse model further supports the role of MADD (summary by MGI: "Mice homozygous for a knock-out allele die shortly after birth due to respiratory failure, are hyporesponsive to tactile stimuli, and exhibit defects in neurotransmitter release with impaired synaptic vesicle trafficking and depletion of synaptic vesicles at the neuromuscular junction.").

You may consider inclusion in other gene panels e.g. for hematologic (low Hb and thrombocytopenia in several) or GI (e.g diarrhea) disorders.
Sources: Literature
Genetic Epilepsy v0.694 UGDH Konstantinos Varvagiannis gene: UGDH was added
gene: UGDH was added to Genetic Epilepsy. Sources: Literature
Mode of inheritance for gene: UGDH was set to BIALLELIC, autosomal or pseudoautosomal
Publications for gene: UGDH were set to 32001716
Phenotypes for gene: UGDH were set to Epileptic encephalopathy, early infantile, 84 - MIM #618792
Penetrance for gene: UGDH were set to Complete
Review for gene: UGDH was set to GREEN
Added comment: Hengel et al (2020 - PMID: 32001716) report on 36 individuals with biallelic UGDH pathogenic variants.

The phenotype corresponded overall to a developmental epileptic encephalopathy with hypotonia, feeding difficulties, severe global DD, moderate or commonly severe ID in all. Hypotonia and motor disorder (incl. spasticity, dystonia, ataxia, chorea, etc) often occurred prior to the onset of seizures. A single individual did not present seizures and 2 sibs had only seizures in the setting of fever.

Affected subjects were tested by exome sequencing and UGDH variants were the only/best candidates for the phenotype following also segregation studies. Many were compound heterozygous or homozygous (~6 families were consanguineous) for missense variants and few were compound heterozygous for missense and pLoF variants. There were no individuals with biallelic pLoF variants identified. Parental/sib studies were all compatible with AR inheritance mode.

UGDH encodes the enzyme UDP-glucose dehydrogenase which converts UDP-glucose to UDP-glucuronate, the latter being a critical component of the glycosaminoglycans, hyaluronan, chondroitin sulfate, and heparan sulfate [OMIM].

Patient fibroblast and biochemical assays suggested a LoF effect of variants leading to impairment of UGDH stability, oligomerization or enzymatic activity (decreased UGDH-catalyzed reduction of NAD+ to NADH / hyaluronic acid production which requires UDP-glucuronate).

Attempts to model the disorder using an already developped zebrafish model (for a hypomorphic LoF allele) were unsuccessful as fish did not exhibit seizures spontaneously or upon induction with PTZ.

Modelling of the disorder in vitro using patient-derived cerebral organoids demonstrated smaller organoids due to reduced number of proliferating neural progenitors.
Sources: Literature
Genetic Epilepsy v0.0 PTS Zornitza Stark gene: PTS was added
gene: PTS was added to Genetic Epilepsy_AustralianGenomics_VCGS. Sources: Australian Genomics Health Alliance Epilepsy Flagship,Expert Review Green,Victorian Clinical Genetics Services
Mode of inheritance for gene: PTS was set to Unknown