rs587781720
Variant summary
Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PP3_StrongPP5
The NM_004168.4(SDHA):c.818C>T(p.Thr273Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000744 in 1,613,930 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T273A) has been classified as Uncertain significance.
Frequency
Consequence
NM_004168.4 missense
Scores
Clinical Significance
Conservation
Publications
- hereditary pheochromocytoma-paragangliomaInheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
- pheochromocytoma/paraganglioma syndrome 5Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Illumina, Ambry Genetics, Labcorp Genetics (formerly Invitae)
- mitochondrial complex II deficiency, nuclear type 1Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
- neurodegeneration with ataxia and late-onset optic atrophyInheritance: AD Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
- Leigh syndromeInheritance: AR Classification: MODERATE Submitted by: Ambry Genetics, ClinGen
- familial isolated dilated cardiomyopathyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- gastrointestinal stromal tumorInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- Leigh syndrome with leukodystrophyInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- mitochondrial complex II deficiencyInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- dilated cardiomyopathy 1GGInheritance: AR Classification: LIMITED Submitted by: Ambry Genetics
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ACMG classification
Our verdict: Uncertain_significance. The variant received 5 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| SDHA | NM_004168.4 | c.818C>T | p.Thr273Ile | missense_variant | Exon 7 of 15 | ENST00000264932.11 | NP_004159.2 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| SDHA | ENST00000264932.11 | c.818C>T | p.Thr273Ile | missense_variant | Exon 7 of 15 | 1 | NM_004168.4 | ENSP00000264932.6 | ||
| ENSG00000286001 | ENST00000651543.1 | n.818C>T | non_coding_transcript_exon_variant | Exon 7 of 24 | ENSP00000499215.1 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152160Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000119 AC: 3AN: 251326 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.00000684 AC: 10AN: 1461770Hom.: 0 Cov.: 57 AF XY: 0.00000275 AC XY: 2AN XY: 727196 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152160Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2AN XY: 74336 show subpopulations
ClinVar
Submissions by phenotype
Pheochromocytoma/paraganglioma syndrome 5 Uncertain:2
This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
This variant is classified as a variant of uncertain significance as there is insufficient evidence to determine its impact on protein function and/or cancer risk. -
Pheochromocytoma/paraganglioma syndrome 5;C5700310:Mitochondrial complex II deficiency, nuclear type 1 Pathogenic:1
This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 273 of the SDHA protein (p.Thr273Ile). This variant is present in population databases (rs587781720, gnomAD 0.003%). This missense change has been observed in individuals with gastrointestinal stromal tumor, pheochromocytoma and paraganglioma (PMID: 23109135, 27011036; external communication, internal data). ClinVar contains an entry for this variant (Variation ID: 141401). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on SDHA protein function. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Neoplasm of brain Pathogenic:1
This sequence change, c.818C>T, in exon 7 of SDHA gene results in the missense change, p.Thr273Ile. This variant is present in population databases (rs587781720, gnomAD 0.003%). This change has been observed in individuals with GIST (PMID: 23109135, 27011036). ClinVar contains an entry for this variant (Variation ID: 141401). c paraganglioma tumor, diagnosed in a 57-year-old male. This amino acid position is highly conserved in available vertebrate species. In addition, this change is predicted to be deleterious by in silico analysis. For these reasons, this variant has been classified as Likely Pathogenic. -
Hereditary cancer-predisposing syndrome Pathogenic:1
The p.T273I variant (also known as c.818C>T), located in coding exon 7 of the SDHA gene, results from a C to T substitution at nucleotide position 818. The threonine at codon 273 is replaced by isoleucine, an amino acid with similar properties. This alteration has been previously identified as a somatic finding in several gastrointestinal stromal tumors (GISTs) demonstrating absence of SDHB and presence of SDHA protein staining by IHC (Belinsky MG et al. Genes Chromosomes Cancer. 2013 Feb;52:214-24; Miettinen M et al. Am. J. Surg. Pathol. 2013 Feb;37:234-40; Boikos SA et al. JAMA Oncol. 2016 Jul;2:922-8). Two of these individuals diagnosed with GIST were also found to carry this alteration in germline DNA (Belinsky MG et al. Genes Chromosomes Cancer. 2013 Feb;52:214-24; Boikos SA et al. JAMA Oncol. 2016 Jul;2:922-8), while no germline specimen was available for the third case (Miettinen M et al. Am. J. Surg. Pathol. 2013 Feb;37:234-40). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
not specified Uncertain:1
DNA sequence analysis of the SDHA gene demonstrated a sequence change, c.818C>T, in exon 7 that results in an amino acid change, p.Thr273Ile. This sequence change has been described in the gnomAD database in three individuals (dbSNPrs587781720). The p.Thr273Ile change has been reported in an individual with gastrointestinal stromal tumor (PMID: 23109135). The p.Thr273Ile change affects a highly conserved amino acid residue located in a domain of the SDHA protein that is known to be functional. The p.Thr273Ile substitution appears to be deleterious using several in-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL). Due to the lack of functional studies, the clinical significance of the p.Thr273Ile change remains unknown at this time. -
Dilated cardiomyopathy 1GG;C5543254:Neurodegeneration with ataxia and late-onset optic atrophy;C5700310:Mitochondrial complex II deficiency, nuclear type 1 Uncertain:1
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not provided Uncertain:1
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 28748451, 23730622, 25394176, 23282968, 24886695, 27986441, 23109135, 36980917, 32741965, 27011036) -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at