Early onset or syndromic epilepsy
Gene: EIF3F
Review and rating collated by Tracy Lester (Oxford Medical Genetics Laboratories Oxford University Hospitals NHS Foundation Trust, 2019_02_06) on behalf of Wessex and West Midlands GLH for GMS Neurology specialist test group, for Clinical Indication R59 'Early onset or syndromic epilepsy'. Review contributors: John Taylor and Helen Lord. Suggested gene rating: Green.Created: 6 Aug 2019, 8:38 p.m. | Last Modified: 6 Aug 2019, 8:38 p.m.
Panel Version: 1.189
AR MR67. Martin et al, 2018 - 9 patients with intellectual disorder from 7 nonconsang families of European ancestry - all hom for the same mutation in EIF3 6/9 had seizures. This variant is one of the most common protein altering variants in the gene and is present at an allele freq of 0.12% but never hom in Non-Finnish Europeans in gnomAD. Functional studies also done on this variant.Created: 6 Aug 2019, 8:31 p.m. | Last Modified: 6 Aug 2019, 8:31 p.m.
Panel Version: 1.188
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Publications
Comment when marking as ready: Not associated with phenotype in OMIM or in Gen2Phen. A single variant (rs141976414, ENSP00000310040.4:p.Phe232Val) has been identified as a homozygote in 9 subjects with intellectual disability and other phenotypic features, 6/9 have seizures. rs141976414 has a frequency of 0.12% in non-Finnish Europeans, however, it is not found as a homozygote in gnomAD (http://gnomad.broadinstitute.org). Supportive functional studies were also provided (PMID 30409806).Created: 19 Nov 2018, 10:20 a.m.
EIF3F was identified in a recent DDD publication (PMID: 30409806) as a cause of autosomal recessive intellectual disability.
All 9 individuals reported were homozygous for a missense variant (Phe232Val - rs141976414) which has a frequency of 0.12% in non-Finnish Europeans.
Features included intellectual disability (9/9), seizures (6/9), behavioral problems (3/9) and sensorineural hearing loss (3/9). Facial features were not specific.
Extensive functional studies were performed and support pathogenicity of the variant in the homozygous state (reduced protein levels, reduced translation rate in line with the role of EIF3F encoding a subunit for eukaryotic translation initiation factor 3, as well as reduced proliferation rates).
As a result this gene can be considered for inclusion in this panel as green (or amber).
Sources: Literature, Expert ReviewCreated: 18 Nov 2018, 10:15 a.m.
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Intellectual disability; Seizures; Behavioral abnormality; Sensorineural hearing impairment
Publications
Phenotypes for gene: EIF3F were changed from Intellectual disability; Seizures; Behavioral abnormality; Sensorineural hearing impairment to Mental retardation, autosomal recessive 67, OMIM:618295
Source Wessex and West Midlands GLH was added to EIF3F.
Source NHS GMS was added to EIF3F.
Konstantinos Varvagiannis: EIF3F was identified in a rece
Gene: eif3f has been classified as Green List (High Evidence).
Gene: eif3f has been classified as Green List (High Evidence).
Gene: eif3f has been classified as Green List (High Evidence).
gene: EIF3F was added gene: EIF3F was added to Genetic epilepsy syndromes. Sources: Literature,Expert Review Mode of inheritance for gene: EIF3F was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: EIF3F were set to 30409806 Phenotypes for gene: EIF3F were set to Intellectual disability; Seizures; Behavioral abnormality; Sensorineural hearing impairment Penetrance for gene: EIF3F were set to Complete Review for gene: EIF3F was set to GREEN