rs59793293
Variant summary
Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong
The ENST00000588735.3(GFAP):c.235C>T(p.Arg79Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000656 in 152,368 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R79L) has been classified as Uncertain significance.
Frequency
Consequence
ENST00000588735.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 18 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
GFAP | NM_002055.5 | c.235C>T | p.Arg79Cys | missense_variant | 1/9 | ENST00000588735.3 | NP_002046.1 | |
GFAP | NM_001363846.2 | c.235C>T | p.Arg79Cys | missense_variant | 1/10 | NP_001350775.1 | ||
GFAP | NM_001242376.3 | c.235C>T | p.Arg79Cys | missense_variant | 1/7 | NP_001229305.1 | ||
GFAP | NM_001131019.3 | c.235C>T | p.Arg79Cys | missense_variant | 1/8 | NP_001124491.1 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
GFAP | ENST00000588735.3 | c.235C>T | p.Arg79Cys | missense_variant | 1/9 | 1 | NM_002055.5 | ENSP00000466598 | P1 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152250Hom.: 0 Cov.: 32
GnomAD4 exome Cov.: 31
GnomAD4 genome AF: 0.00000656 AC: 1AN: 152368Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74514
ClinVar
Submissions by phenotype
not provided Pathogenic:2Other:1
Pathogenic, criteria provided, single submitter | clinical testing | GeneDx | Nov 19, 2021 | Published functional studies demonstrate that p.(R79C) significantly increases GFAP aggregation in zebra fish in comparison to wild-type (Lee et al., 2017) and impairs mitochondrial transfer from astrocytes to neighboring neurons (Gao et al., 2019); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Not observed in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 12509855, 23254569, 15696488, 18584981, 12034785, 12175861, 21533827, 11567214, 12581808, 15732097, 19128991, 18463287, 31484723, 33176815, 31327963, 11138011, 33084218, 34146839, 34692893, 17894839, 28882119) - |
not provided, no classification provided | literature only | Epithelial Biology; Institute of Medical Biology, Singapore | - | - - |
Pathogenic, criteria provided, single submitter | clinical testing | Labcorp Genetics (formerly Invitae), Labcorp | Aug 05, 2022 | This variant is not present in population databases (gnomAD no frequency). For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Arg79 amino acid residue in GFAP. Other variant(s) that disrupt this residue have been observed in individuals with GFAP-related conditions (PMID: 11138011), which suggests that this may be a clinically significant amino acid residue. Experimental studies have shown that this missense change affects GFAP function (PMID: 28882119). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 16171). This missense change has been observed in individual(s) with Alexander disease (PMID: 11138011, 18584981, 23254569). In at least one individual the variant was observed to be de novo. This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 79 of the GFAP protein (p.Arg79Cys). - |
Alexander disease Pathogenic:2Other:1
Pathogenic, no assertion criteria provided | literature only | OMIM | Nov 01, 2007 | - - |
not provided, no classification provided | literature only | GeneReviews | - | - - |
Pathogenic, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Jul 25, 2022 | The GFAP c.235C>T p.(Arg79Cys) missense variant has been reported in a heterozygous state in at least seven individuals with Alexander disease, including five in whom it occurred in a de novo state (PMID: 11138011; PMID: 15696488; PMID: 18584981; PMID: 23254569; PMID: 31484723; PMID: 33176815). The c.235C>T variant is reported in the Genome Aggregation Database in one allele at a frequency of 0.000015 in the European (non-Finnish) population (version 3.1.2). Compared to wild-type GFAP, the p.(Arg79Cys) variant has been shown to significantly increase GFAP aggregation when expressed in zebrafish (PMID: 28882119). Mass spectroscopy studies in a patient with the variant suggested that levels of variant GFAP were lower than those of wild-type, suggesting an intrinsic toxicity of the variant form (PMID: 31484723). When expressed in human pluripotent stem cells induced to differentiate into astrocytes, the variant also impaired mitochondrial transfer from astrocytes and reduced astrocytic CD38 expression (PMID: 31327963). This variant was identified in a de novo state in the proband. Based on the available evidence, the c.235C>T (p.Arg79Cys) variant is classified as pathogenic for Alexander disease. - |
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at