rs746666691
Variant summary
Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_ModerateBS2
The NM_003001.5(SDHC):c.22C>A(p.His8Asn) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000149 in 1,612,810 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. 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. H8Q) has been classified as Uncertain significance.
Frequency
Consequence
NM_003001.5 missense, splice_region
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -6 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
SDHC | NM_003001.5 | c.22C>A | p.His8Asn | missense_variant, splice_region_variant | Exon 2 of 6 | ENST00000367975.7 | NP_002992.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152186Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000281 AC: 7AN: 248980Hom.: 0 AF XY: 0.0000371 AC XY: 5AN XY: 134776
GnomAD4 exome AF: 0.0000157 AC: 23AN: 1460624Hom.: 0 Cov.: 30 AF XY: 0.0000234 AC XY: 17AN XY: 726748
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152186Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74342
ClinVar
Submissions by phenotype
Gastrointestinal stromal tumor;C1854336:Paragangliomas 3 Uncertain:1
This sequence change replaces histidine, which is basic and polar, with asparagine, which is neutral and polar, at codon 8 of the SDHC protein (p.His8Asn). This variant is present in population databases (rs746666691, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with SDHC-related conditions. ClinVar contains an entry for this variant (Variation ID: 1513452). An algorithm developed to predict the effect of missense changes on protein structure and function outputs the following: PolyPhen-2: "Benign". The asparagine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect 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. -
Paragangliomas 3 Uncertain:1
The missense variant p.H8N in SDHC (NM_003001.5) has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. The p.His8Asn variant is novel (not in any individuals) in 1000 Genomes. There is a small physicochemical difference between histidine and asparagine, which is not likely to impact secondary protein structure as these residues share similar properties. In silico tools predict the variant to be tolerated. The residue is conserved across species. The amino acid change p.His8Asn in SDHC is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. For these reasons, this variant has been classified as Uncertain Significance. -
Hereditary cancer-predisposing syndrome Uncertain:1
The p.H8N variant (also known as c.22C>A), located in coding exon 2 of the SDHC gene, results from a C to A substitution at nucleotide position 22. The histidine at codon 8 is replaced by asparagine, an amino acid with similar properties. This alteration was identified in 2/1358 non-cancer control individuals and in 0/57 cases, in a study looking at cancer predisposition mutations in patients with cutaneous melanoma and a history of at least two additional non-cutaneous melanoma primary cancers (Pritchard AL et al. PLoS One, 2018 Apr;13:e0194098). This amino acid position is well 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at