5-230935-C-T
Variant summary
Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4BP6
The NM_004168.4(SDHA):c.830C>T(p.Thr277Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000101 in 1,613,876 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign 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. T277K) 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: Likely_benign. The variant received -2 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| SDHA | NM_004168.4 | c.830C>T | p.Thr277Met | 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.830C>T | p.Thr277Met | missense_variant | Exon 7 of 15 | 1 | NM_004168.4 | ENSP00000264932.6 | ||
| ENSG00000286001 | ENST00000651543.1 | n.830C>T | non_coding_transcript_exon_variant | Exon 7 of 24 | ENSP00000499215.1 |
Frequencies
GnomAD3 genomes AF: 0.0000920 AC: 14AN: 152164Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000836 AC: 21AN: 251232 AF XY: 0.0000957 show subpopulations
GnomAD4 exome AF: 0.000102 AC: 149AN: 1461712Hom.: 0 Cov.: 57 AF XY: 0.0000963 AC XY: 70AN XY: 727172 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000920 AC: 14AN: 152164Hom.: 0 Cov.: 33 AF XY: 0.0000673 AC XY: 5AN XY: 74344 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:2
In the published literature, this variant has been reported in individuals affected with PPGL (PMID: 28384794 (2017)) and a rare cancer (PMID: 32570879 (2020)). The variant has also been reported in individuals affected with a cardiomyopathy (PMIDs: 28798025 (2017), 30775854 (2019)). The frequency of this variant in the general population, 0.00018 (20/113552 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant. -
Observed in an individual with an adrenal paraganglioma (PMID: 28384794); In silico analysis indicates that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 28798025, 35883565, 28384794, 28546994, 30775854, 32570879, 29978154, 38473309) -
Pheochromocytoma/paraganglioma syndrome 5 Uncertain:1Benign:1
This variant is considered likely benign. This variant has been observed at a population frequency that is significantly greater than expected given the associated disease prevalence and penetrance. -
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. -
Mitochondrial complex II deficiency, nuclear type 1 Uncertain:1
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
Leigh syndrome Uncertain:1
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
Skeletal myopathy Uncertain:1
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Dilated cardiomyopathy 1GG Uncertain:1
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Hereditary cancer-predisposing syndrome Uncertain:1
The p.T277M variant (also known as c.830C>T), located in coding exon 7 of the SDHA gene, results from a C to T substitution at nucleotide position 830. The threonine at codon 277 is replaced by methionine, an amino acid with similar properties. This variant was reported in a Polish individual with unilateral adrenal tumor (Bausch B et al. JAMA Oncol, 2017 Sep;3:1204-1212) but has also been reported in multiple individuals without personal or family histories of paragangliomas or pheochromocytomas (Rana HQ et al. Cancers (Basel), 2024 Feb;16:). This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -
Dilated cardiomyopathy 1GG;C3279992:Pheochromocytoma/paraganglioma syndrome 5;C5543254:Neurodegeneration with ataxia and late-onset optic atrophy;C5700310:Mitochondrial complex II deficiency, nuclear type 1 Uncertain:1
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Pheochromocytoma/paraganglioma syndrome 5;C5700310:Mitochondrial complex II deficiency, nuclear type 1 Benign:1
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Hereditary pheochromocytoma-paraganglioma Benign:1
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at