3-100728759-C-T
Variant summary
Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM2PM5PP3_ModeratePP5_Very_Strong
The NM_006070.6(TFG):c.316C>T(p.Arg106Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000292 in 1,611,608 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. R106H) has been classified as Likely pathogenic.
Frequency
Consequence
NM_006070.6 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 16 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
TFG | NM_006070.6 | c.316C>T | p.Arg106Cys | missense_variant | 4/8 | ENST00000240851.9 | NP_006061.2 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
TFG | ENST00000240851.9 | c.316C>T | p.Arg106Cys | missense_variant | 4/8 | 1 | NM_006070.6 | ENSP00000240851 | P4 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152096Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000401 AC: 10AN: 249380Hom.: 0 AF XY: 0.0000519 AC XY: 7AN XY: 134908
GnomAD4 exome AF: 0.0000315 AC: 46AN: 1459512Hom.: 0 Cov.: 30 AF XY: 0.0000358 AC XY: 26AN XY: 726102
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152096Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74276
ClinVar
Submissions by phenotype
not provided Pathogenic:2
Pathogenic, no assertion criteria provided | clinical testing | Genetic Services Laboratory, University of Chicago | May 10, 2022 | DNA sequence analysis of the TGF gene demonstrated a sequence change, c.316C>T, in exon 4 that results in an amino acid change, p.Arg106Cys. The p.Arg106Cys change affects a highly conserved amino acid residue located in a domain of the TFG protein that is not known to be functional. In-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL) provide contradictory results for the p.Arg106Cys substitution. This sequence change has been described in the gnomAD database with a frequency of 0.0086% in the non-Finnish European subpopulation (dbSNP rs587777175). This pathogenic sequence change has previously been described in the homozygous state in individuals with autosomal recessive spastic paraplegia (PMID: 23479643, 27492651, 29971521). Heterozygous pathogenic variants have also been described in individuals with autosomal dominant hereditary motor and sensory neuropathy (PMID: 22883144). However, variants associated with autosomal dominant conditions appear to be located in a different region of the protein than the p.Arg106Cys substitution (PMID: 26945032). Heterozygous carriers of the p.Arg106Cys change have not been reported to be affected. The TGF cDNA reference sequence used is NM_006070.5 - |
Pathogenic, criteria provided, single submitter | clinical testing | GeneDx | Jun 30, 2021 | Published functional studies demonstrate damaging effects on protein secretion from the endoplasmic reticulum (ER), ER morphology, and mitochondrial dysfunction (Beetz et al., 2013; Harlalka et al., 2016; Slosarek et al., 2018); Not observed at a significant frequency in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 27535533, 32488467, 30157421, 30221345, 26945032, 24954637, 27813252, 25098539, 24613659, 27601211, 27492651, 29971521, 23479643) - |
Hereditary spastic paraplegia 57 Pathogenic:2
Pathogenic, no assertion criteria provided | literature only | OMIM | Mar 26, 2013 | - - |
Pathogenic, no assertion criteria provided | clinical testing | Clinical Genetics Laboratory, University Hospital Schleswig-Holstein | Oct 05, 2021 | - - |
Inborn genetic diseases Pathogenic:1
Pathogenic, criteria provided, single submitter | clinical testing | Ambry Genetics | Dec 18, 2020 | The p.R106C variant (also known as c.316C>T), located in coding exon 3 of the TFG gene, results from a C to T substitution at nucleotide position 316. The arginine at codon 106 is replaced by cysteine, an amino acid with highly dissimilar properties. This variant was detected in the homozygous state in multiple unrelated families and segregates with autosomal recessive hereditary spastic paraplegia and optic nerve hypoplasia in affected relatives (Beetz C et al. Proc Natl Acad Sci U S A, 2013 Mar;110:5091-6; Harlalka GV et al. Hum Mutat, 2016 11;37:1157-1161; Kvarnung M et al. Clin Genet, 2018 12;94:528-537; Catania A et al. Neurogenetics, 2018 08;19:179-187). Functional studies with this alteration show impaired TFG protein oligomerization leading to abnormal ER function (Beetz C et al. Proc Natl Acad Sci U S A, 2013 Mar;110:5091-6; Harlalka GV et al. Hum Mutat, 2016 11;37:1157-1161; Slosarek EL et al. Cell Rep, 2018 08;24:2248-2260). Based on the supporting evidence, this variant is pathogenic for spastic paraplegia 57 (SPG57); however, the clinical significance for hereditary motor and sensory neuropathy, Okinawa type (HMSN-P) is unclear. - |
Hereditary motor and sensory neuropathy, Okinawa type;C3714897:Hereditary spastic paraplegia 57 Pathogenic:1
Pathogenic, criteria provided, single submitter | clinical testing | Labcorp Genetics (formerly Invitae), Labcorp | Jul 25, 2023 | For these reasons, this variant has been classified as Pathogenic. Experimental studies have shown that this missense change affects TFG function (PMID: 23479643, 27492651, 30157421). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt TFG protein function. ClinVar contains an entry for this variant (Variation ID: 100909). This missense change has been observed in individuals with autosomal recessive hereditary spastic paraplegia (PMID: 23479643, 27492651, 29971521). It has also been observed to segregate with disease in related individuals. This variant is present in population databases (rs587777175, gnomAD 0.009%). This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 106 of the TFG protein (p.Arg106Cys). - |
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at