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Early onset or syndromic epilepsy v2.404 | AIMP1 | Arina Puzriakova Phenotypes for gene: AIMP1 were changed from Leukodystrophy, hypomyelinating 3 260600 to Leukodystrophy, hypomyelinating, 3, OMIM:260600 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Early onset or syndromic epilepsy v2.0 | RARS |
Konstantinos Varvagiannis gene: RARS was added gene: RARS was added to Genetic epilepsy syndromes. Sources: Literature Mode of inheritance for gene: RARS was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: RARS were set to 31814314; 28905880; 24777941 Phenotypes for gene: RARS were set to Leukodystrophy, hypomyelinating, 9 616140 Penetrance for gene: RARS were set to Complete Review for gene: RARS was set to GREEN Added comment: Biallelic pathogenic RARS1 variants cause Leukodystrophy, hypomyelinating, 9 (# 616140). The current review was based primarily on PMID: 31814314 (Mendes et al, 2019) providing details on 20 affected individuals from 15 families. 5 of these patients were included in a previous publication (Wolf et al, 2014 - PMID: 24777941) sharing authors with this study. Clinical presentation and severity can be highly variable. However, among the 15 patients of relevant age (5/20 deceased at an early age), ID was observed in 13 (in 6/13 mild-moderate, in 7/13 severe/profound). Epilepsy was reported in half (10/20) with seizures being refractory to treatment in most and the phenotype corresponding to an infantile epileptic encephalopathy. DD and seizures were the presenting feature in 7 and 5 patients respectively, while in other cases presenting features were less specific (eg. failure to thrive in 1/20, irritabilty in 2/20). As a result the gene appears to be relevant to both DD/ID and epilepsy panels. RARS1 encodes the cytoplasmic arginyl-tRNA synthetase 1, which is a component of the aminoacyl-tRNA synthetase complex (OMIM and Wolf et al, 2014 - PMID: 24777941). Aminoacyl-tRNA synthetases catalyze the aminoacylation ('charging') of tRNA by (with) their cognate amino acid. Utilisation of alternative initiation codons, from a single mRNA transcript, results in translation of a long and a short protein isoform (Zheng et al 2006 - PMID: 16430231). The long isoform is needed for the formation of the multi-synthetase complex (MSC), while the short is free in the cytoplasm and does not have any interaction with the MSC. The long isoform appears to be essential for protein synthesis (discussed with several refs provided in PMID: 28905880 - Nafisinia et al, 2017). The role of variants has been supported in several patients by additional studies - among others : [PMID 31814314] Impaired Arginyl-tRNA synthetase activity was demonstrated in fibroblasts from 3 patients. Activity was normal in one additional individual compound heterozygous for a variant affecting initiation codon and a missense one. Western blot however demonstrated presence mainly of the short protein isoform. The authors suggest that this isoform possibly contributed to enzymatic activity. The long isoform which is needed for the MSC complex was only represented by a faint band in the Western Blot of the same individual. [PMID: 28905880] Using fibroblasts from an affected subject homozygous for a missense variant (NM_002887.3:c.5A>G / p.Asp2Gly) and controls, a 75% reduction of the long isoform was shown upon WB. The short isoform was present at similar levels. As the N-terminus (of the long isoform) mediates interaction with the MSC (and AIMP1), assembly of the latter was 99% reduced in patient fibroblasts. Proliferation of patient fibroblasts was significantly reduced when cultured in a medium with limited arginine, a finding which was thought to reflect inefficient protein synthesis. Mutations in other genes encoding for aminoacyl-tRNA synthetases (eg. AARS1, VARS1) or scaffolding proteins of the multisynthetase complex (eg. AIMP1 and AIMP2) lead to neurodevelopmental disorders with overlapping phenotype [most genes rated green in both the ID and epilepsy panel]. Sources: Literature |
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Early onset or syndromic epilepsy v1.191 | AIMP1 | Rebecca Foulger Source Wessex and West Midlands GLH was added to AIMP1. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Early onset or syndromic epilepsy v1.190 | AIMP1 | Rebecca Foulger Source NHS GMS was added to AIMP1. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Early onset or syndromic epilepsy v1.189 | AIMP1 | Rebecca Foulger edited their review of gene: AIMP1: Added comment: 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. ; Changed rating: AMBER | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Early onset or syndromic epilepsy v1.188 | AIMP1 | Tracy Lester reviewed gene: AIMP1: Rating: GREEN; Mode of pathogenicity: ; Publications: 24958424, 21092922 ; Phenotypes: Leukodystrophy, hypomyelinating, 260600; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Early onset or syndromic epilepsy v1.1 | AIMP2 |
Konstantinos Varvagiannis gene: AIMP2 was added gene: AIMP2 was added to Genetic epilepsy syndromes. Sources: Literature Mode of inheritance for gene: AIMP2 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: AIMP2 were set to 29215095 Phenotypes for gene: AIMP2 were set to Leukodystrophy, hypomyelinating, 17 (MIM 618006) Penetrance for gene: AIMP2 were set to Complete Review for gene: AIMP2 was set to AMBER Added comment: Biallelic pathogenic variants in AIMP2 cause Leukodystrophy, hypomyelinating, 17 (MIM 618006). 3 individuals from 2 unrelated consanguineous families, of Indian origin have been reported (all in PMID: 29215095). The phenotype consisted of feeding difficulties, lack of development with intellectual disability and seizures (3/3) as well as brain MRI abnormalities (cerebral and cerebellar atrophy, hypo-intensities of the basal ganglia on T2w sequences). Severe microcephaly was observed in 2 patients for whom this information was available (birth measurements not specified). All patients described to date were homozygous for a nonsense variant [NM_006303.3:c.105C>A or p.(Tyr35Ter)] which appears to be a founder mutation in this population. Quantitative reverse transcription PCR demonstrated reduced mRNA levels in peripheral lymphocytes, but this decrease was not significant compared to controls (the authors presume low level of NMD). Previous mouse models provide some - but not substantial - support. The authors note marked similarity with the phenotype associated with AIMP1 (Leukodystrophy, hypomyelinating, 3 - MIM 260600), another auxiliary protein of the macromolecular multienzyme multi-tRNA synthetase complex. AIMP1 is listed in the current panel as green. AIMP2 is not associated with any phenotype in G2P. As a result, this gene can be considered for inclusion in this panel probably as amber. Sources: Literature |
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Early onset or syndromic epilepsy v0.1459 | AIMP1 | Rebecca Foulger Added comment: Comment on mode of inheritance: Updated MOI from monoallelic to biallelic to match OMIM, Gene2Phenotype, and other relevant panels. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Early onset or syndromic epilepsy v0.1459 | AIMP1 | Rebecca Foulger Mode of inheritance for gene: AIMP1 was changed from MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown to BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Early onset or syndromic epilepsy | AIMP1 | Sarah Leigh marked gene: AIMP1 as ready | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Early onset or syndromic epilepsy | AIMP1 | Sarah Leigh classified AIMP1 as Green List (high evidence) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Early onset or syndromic epilepsy | AIMP1 | Arianna Tucci reviewed gene: AIMP1 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Early onset or syndromic epilepsy | AIMP1 | Sarah Leigh Added gene to panel |