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Early onset or syndromic epilepsy

Gene: UGDH

Green List (high evidence)

UGDH (UDP-glucose 6-dehydrogenase)
EnsemblGeneIds (GRCh38): ENSG00000109814
EnsemblGeneIds (GRCh37): ENSG00000109814
OMIM: 603370, Gene2Phenotype
UGDH is in 2 panels

3 reviews

Sarah Leigh (Genomics England Curator)

The rating of this gene has been updated following NHS Genomic Medicine Service approval.
Created: 3 Mar 2022, 5:34 p.m. | Last Modified: 3 Mar 2022, 5:34 p.m.
Panel Version: 2.491

Arina Puzriakova (Genomics England Curator)

Comment on list classification: There is sufficient evidence to rate this gene Green at the next GMS panel update.

Multiple patients from over 20 unrelated families with severe epilepsy, mostly ranging from neonatal to infantile onset developmental epileptic encephalopathy.
Created: 5 Oct 2020, 4:24 p.m. | Last Modified: 5 Oct 2020, 4:24 p.m.
Panel Version: 2.158

Konstantinos Varvagiannis (Other)

Green List (high evidence)

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
Created: 7 May 2020, 9:15 a.m.

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Epileptic encephalopathy, early infantile, 84 - MIM #618792



Mode of Inheritance
BIALLELIC, autosomal or pseudoautosomal
  • Expert Review Green
  • Epileptic encephalopathy, early infantile, 84 - MIM #618792
Clinvar variants
Variants in UGDH
Panels with this gene

History Filter Activity

3 Mar 2022, Gel status: 3

Removed Tag

Sarah Leigh (Genomics England Curator)

Tag for-review was removed from gene: UGDH.

3 Mar 2022, Gel status: 3

Added New Source, Status Update

Sarah Leigh (Genomics England Curator)

Source Expert Review Green was added to UGDH. Rating Changed from Amber List (moderate evidence) to Green List (high evidence)

5 Oct 2020, Gel status: 2

Entity classified by Genomics England curator

Arina Puzriakova (Genomics England Curator)

Gene: ugdh has been classified as Amber List (Moderate Evidence).

5 Oct 2020, Gel status: 0

Added Tag

Arina Puzriakova (Genomics England Curator)

Tag for-review tag was added to gene: UGDH.

7 May 2020, Gel status: 0

Created, Added New Source, Set mode of inheritance, Set publications, Set Phenotypes, Set penetrance

Konstantinos Varvagiannis (Other)

gene: UGDH was added gene: UGDH was added to Genetic epilepsy syndromes. 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