11-61430178-C-A

Position:

• chr11-61430178-C-A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PVS1_Strong PM2 PP5

The NM_017841.4(SDHAF2):​c.32C>A​(p.Ser11Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,854 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SDHAF2 NM_017841.4 stop_gained
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 1.11

Genes affected

SDHAF2 (HGNC:26034): (succinate dehydrogenase complex assembly factor 2) This gene encodes a mitochondrial assembly factor needed for the flavination of a succinate dehydrogenase complex subunit (SDHA), which is required for activity of the succinate dehydrogenase complex. Mutations in this gene are associated with paraganglioma. [provided by RefSeq, May 2022]

(HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.936 CDS is truncated, and there are 3 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-61430178-C-A is Pathogenic according to our data. Variant chr11-61430178-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 2158448.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SDHAF2	NM_017841.4	c.32C>A	p.Ser11Ter	stop_gained	1/4	ENST00000301761.7	NP_060311.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SDHAF2	ENST00000301761.7	c.32C>A	p.Ser11Ter	stop_gained	1/4	1	NM_017841.4	ENSP00000301761	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461854 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727222

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 33

Bravo AF: 0.0000113

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary pheochromocytoma-paraganglioma Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 05, 2022

For these reasons, this variant has been classified as Pathogenic. This variant has not been reported in the literature in individuals affected with SDHAF2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Ser11*) in the SDHAF2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in SDHAF2 are known to be pathogenic (PMID: 22241717, 26096992). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 30, 2023

The p.S11* variant (also known as c.32C>A), located in coding exon 1 of the SDHAF2 gene, results from a C to A substitution at nucleotide position 32. This changes the amino acid from a serine to a stop codon within coding exon 1. The predicted stop codon occurs in the 5’ end of theSDHAF2 gene. Premature termination codons in the 5’ end of a gene have been reported to escape nonsense-mediated mRNAdecay and/or lead to re-initiation (Rivas et al. Science. 2015 May 8;348(6235):666-9; Lindeboom et al. Nat Genet. 2016 Oct;48(10):1112-8; Rhee et al. Sci Rep. 2017 May 10;7(1):1653). The exact functional effect of this alteration is unknown. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.50
CADD	Pathogenic	37
DANN	Benign	0.95
Eigen	Uncertain	0.28
Eigen_PC	Benign	-0.024
FATHMM_MKL	Benign	0.36	N
MutationTaster	Benign	1.0	A;A
Vest4		0.48, 0.38, 0.49, 0.34, 0.47
GERP RS		3.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.14		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs148425779; hg19: chr11-61197650;