chr1-161356841-G-A

Position:

• chr1-161356841-G-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_003001.5(SDHC):​c.405+1G>A variant causes a splice donor change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SDHC NM_003001.5 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, single submitter P:5
• Conservation: PhyloP100: 7.29

Genes affected

SDHC (HGNC:10682): (succinate dehydrogenase complex subunit C) This gene encodes one of four nuclear-encoded subunits that comprise succinate dehydrogenase, also known as mitochondrial complex II, a key enzyme complex of the tricarboxylic acid cycle and aerobic respiratory chains of mitochondria. The encoded protein is one of two integral membrane proteins that anchor other subunits of the complex, which form the catalytic core, to the inner mitochondrial membrane. There are several related pseudogenes for this gene on different chromosomes. Mutations in this gene have been associated with paragangliomas. Alternatively spliced transcript variants have been described. [provided by RefSeq, May 2013]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-161356841-G-A is Pathogenic according to our data. Variant chr1-161356841-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 7244.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr1-161356841-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SDHC	NM_003001.5	c.405+1G>A		splice_donor_variant		ENST00000367975.7	NP_002992.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SDHC	ENST00000367975.7	c.405+1G>A		splice_donor_variant		1	NM_003001.5	ENSP00000356953	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, single submitter

Submissions by phenotype

Carney triad Pathogenic:1

Likely pathogenic, no assertion criteria provided

clinical testing

Section on Endocrinology and Genetics, National Institutes of Health / The Eunice Kennedy Shriver National Institute of Child Health and Human Development

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Gastrointestinal stromal tumor;C1854336:Paragangliomas 3 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 20, 2019

For these reasons, this variant has been classified as Pathogenic. Nucleotide substitutions within the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Experimental studies have shown that this variant disrupts mRNA splicing (PMID: 17667967). Disruption of this splice site has been observed in individuals affected with paraganglioma and/or gastrointestinal stromal tumors (PMID: 17667967, 26173966, 24402737, 12658451, 21173220). ClinVar contains an entry for this variant (Variation ID: 7244). This variant is not present in population databases (ExAC no frequency). This sequence change affects a donor splice site in the last intron (intron 5) of the SDHC gene. While this is not anticipated to result in nonsense mediated decay, it likely alters RNA splicing and results in a disrupted protein product. -

Gastrointestinal stromal tumor Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Jan 04, 2011

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Carney-Stratakis syndrome Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Jan 04, 2011

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Hereditary pheochromocytoma-paraganglioma Pathogenic:1

Likely pathogenic, no assertion criteria provided

research

Section on Medical Neuroendocrinolgy, National Institutes of Health

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Pathogenic	0.34
CADD	Pathogenic	33
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.99
FATHMM_MKL	Uncertain	0.94	D
MutationTaster	Benign	1.0	D;D;D;D;D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.97		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.97		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs587776653; hg19: chr1-161326631;