rs146276662
Variant summary
Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6
The NM_003002.4(SDHD):c.118A>C(p.Ile40Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000471 in 1,613,874 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. I40T) has been classified as Likely benign.
Frequency
Consequence
NM_003002.4 missense
Scores
Clinical Significance
Conservation
Publications
- hereditary pheochromocytoma-paragangliomaInheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
- pheochromocytomaInheritance: AD Classification: DEFINITIVE Submitted by: G2P
- pheochromocytoma/paraganglioma syndrome 1Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
- Carney-Stratakis syndromeInheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet
- mitochondrial complex II deficiency, nuclear type 1Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- renal cell carcinomaInheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
- mitochondrial complex 2 deficiency, nuclear type 3Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics
- mitochondrial complex II deficiencyInheritance: AR Classification: MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet
- Cowden diseaseInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- intestinal cancerInheritance: AD Classification: LIMITED Submitted by: G2P
- mitochondrial diseaseInheritance: AR Classification: LIMITED Submitted by: ClinGen
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ACMG classification
Our verdict: Likely_benign. The variant received -3 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| SDHD | NM_003002.4 | c.118A>C | p.Ile40Leu | missense_variant | Exon 2 of 4 | ENST00000375549.8 | NP_002993.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000394 AC: 6AN: 152164Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000278 AC: 7AN: 251478 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 0.0000479 AC: 70AN: 1461710Hom.: 0 Cov.: 30 AF XY: 0.0000344 AC XY: 25AN XY: 727172 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000394 AC: 6AN: 152164Hom.: 0 Cov.: 32 AF XY: 0.0000403 AC XY: 3AN XY: 74350 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Hereditary pheochromocytoma-paraganglioma Uncertain:1Benign:1
This missense variant replaces isoleucine with leucine at codon 40 of the SDHD protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in individuals affected with Cowden-like syndrome (PMID: 22829200), or head-neck paraganglioma (PMID: 19351833). This variant has been identified in 7/251478 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance.
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. The evidence from the literature, in combination with allele frequency data from public databases where available, was sufficient to determine this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign.
Pheochromocytoma;C1847319:Carney-Stratakis syndrome;C1868633:Paragangliomas with sensorineural hearing loss;CN166604:Cowden syndrome 3 Uncertain:1
This sequence change replaces isoleucine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 40 of the SDHD protein (p.Ile40Leu). This variant is present in population databases (rs146276662, gnomAD 0.005%). This missense change has been observed in individual(s) with Cowden or Cowden-like syndrome (PMID: 22829200). ClinVar contains an entry for this variant (Variation ID: 218581). 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 SDHD 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.
Carney-Stratakis syndrome;C3494181:Pheochromocytoma/paraganglioma syndrome 1;C5436934:Mitochondrial complex 2 deficiency, nuclear type 3 Uncertain:1
not provided Uncertain:1
The SDHD c.118A>C (p.Ile40Leu) variant has been reported in the published literature in an individual with Cowden or Cowden-like syndrome (PMID: 22829200 (2012)) and in extracranial solid tumors from pediatric patients (PMID: 35739269 (2022)). The frequency of this variant in the general population, 0.000062 (7/113770 chromosomes in European (Non-Finnish) subpopulation (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is higher than would generally be expected for pathogenic variants in this gene. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded conflicting predictions that this variant is deleterious or benign. Based on the available information, we are unable to determine the clinical significance of this variant.
Pheochromocytoma/paraganglioma syndrome 1 Uncertain:1
Hereditary cancer-predisposing syndrome Benign:1
This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at