5-224496-C-T
Variant summary
Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1PP3_Moderate
The NM_004168.4(SDHA):c.287C>T(p.Thr96Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000347 in 1,612,784 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T96P) 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 4 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| SDHA | NM_004168.4 | c.287C>T | p.Thr96Ile | missense_variant | Exon 3 of 15 | ENST00000264932.11 | NP_004159.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000526 AC: 8AN: 152196Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251148 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.0000329 AC: 48AN: 1460588Hom.: 0 Cov.: 32 AF XY: 0.0000248 AC XY: 18AN XY: 726602 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000526 AC: 8AN: 152196Hom.: 0 Cov.: 33 AF XY: 0.0000538 AC XY: 4AN XY: 74358 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Pheochromocytoma/paraganglioma syndrome 5 Uncertain:3
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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. -
not provided Uncertain:3
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; Has not been previously published as pathogenic or benign to our knowledge -
The SDHA c.287C>T (p.Thr96Ile) variant has been briefly reported in the published literature in individuals with diverse tumors/cancers (PMID: 38473309 (2024)), but not specifically paraganglioma-pheochromocytoma (PGL-PCC) syndrome. The frequency of this variant in the general population, 0.000031 (4/128870 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 damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -
p.Thr96Ile (c.287C>T) in exon 3 of the SDHA gene (NM_004168.2) Seen in a patient with multiple unexplained VF arrests. Given the lack of case data and the poor fit for the phenotype, we consider this a variant of uncertain significance and we do not feel it is suitable for assessing risk in healthy relatives ("predictive genetic testing"). -
Dilated cardiomyopathy 1GG Uncertain:1
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Pheochromocytoma/paraganglioma syndrome 5;C5700310:Mitochondrial complex II deficiency, nuclear type 1 Uncertain:1
This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 96 of the SDHA protein (p.Thr96Ile). This variant is present in population databases (rs377620054, gnomAD 0.004%). This variant has not been reported in the literature in individuals affected with SDHA-related conditions. ClinVar contains an entry for this variant (Variation ID: 239666). 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) indicates that this missense variant is not expected to disrupt SDHA protein function with a negative predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
Hereditary cancer-predisposing syndrome Uncertain:1
The p.T96I variant (also known as c.287C>T), located in coding exon 3 of the SDHA gene, results from a C to T substitution at nucleotide position 287. The threonine at codon 96 is replaced by isoleucine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
B-lymphoblastic leukemia/lymphoma with hypodiploidy Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at