rs1126557
Variant summary
Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1PP3_Strong
The NM_004168.4(SDHA):c.1787A>G(p.Asp596Gly) variant causes a missense change. The variant allele was found at a frequency of 0.0000124 in 1,613,830 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. D596Y) 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_pathogenic. The variant received 6 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| SDHA | NM_004168.4 | c.1787A>G | p.Asp596Gly | missense_variant | Exon 13 of 15 | ENST00000264932.11 | NP_004159.2 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| SDHA | ENST00000264932.11 | c.1787A>G | p.Asp596Gly | missense_variant | Exon 13 of 15 | 1 | NM_004168.4 | ENSP00000264932.6 | ||
| ENSG00000286001 | ENST00000651543.1 | n.*520A>G | non_coding_transcript_exon_variant | Exon 12 of 24 | ENSP00000499215.1 | |||||
| ENSG00000286001 | ENST00000651543.1 | n.*520A>G | 3_prime_UTR_variant | Exon 12 of 24 | ENSP00000499215.1 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152208Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000199 AC: 5AN: 250880 AF XY: 0.0000147 show subpopulations
GnomAD4 exome AF: 0.0000130 AC: 19AN: 1461622Hom.: 0 Cov.: 32 AF XY: 0.0000138 AC XY: 10AN XY: 727116 show subpopulations ⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152208Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74360 show subpopulations ⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
ClinVar
Submissions by phenotype
not provided Uncertain:3
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The frequency of this variant in the general population, 0.00017 (6/35422 chromosomes, http://gnomad.broadinstitute.org), is uninformative in assessment of its pathogenicity. In the published literature, the variant has been reported in an individual with combined complex II/III deficiency (PMID: 29488078 (2018)). 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. -
In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 29488078) -
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:2
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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 aspartic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 596 of the SDHA protein (p.Asp596Gly). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with clinical features of autosomal recessive mitochondrial complex II deficiency (PMID: 29488078). ClinVar contains an entry for this variant (Variation ID: 472358). 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 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.D596G variant (also known as c.1787A>G), located in coding exon 13 of the SDHA gene, results from an A to G substitution at nucleotide position 1787. The aspartic acid at codon 596 is replaced by glycine, an amino acid with similar properties. This alteration was identified via whole exome sequencing in conjunction with SDHA p.D135N in a three-year-old proband with combined complex II/III deficiency; however, the authors did not determine phase of the alterations, nor were any functional studies performed (Tan AP et al. Childs Nerv Syst 2018 Apr;34(4):601-603). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
SDHA-related disorder Uncertain:1
The SDHA c.1787A>G variant is predicted to result in the amino acid substitution p.Asp596Gly. This variant has been reported along with a second variant in an individual with combined complex II/III deficiency (Tan et al. 2018. PubMed ID: 29488078). This variant is reported in 0.017% of alleles in individuals of Latino descent in gnomAD and has an interpretation of uncertain significance in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/472358/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at