rs1554983610

Positions:

• chr11-61430171-A-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_017841.4(SDHAF2):​c.25A>G​(p.Thr9Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 33)
• Consequence: SDHAF2 NM_017841.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4 B:1
• Conservation: PhyloP100: 0.249

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_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.03352076).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SDHAF2	NM_017841.4	c.25A>G	p.Thr9Ala	missense_variant	1/4	ENST00000301761.7	NP_060311.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SDHAF2	ENST00000301761.7	c.25A>G	p.Thr9Ala	missense_variant	1/4	1	NM_017841.4	ENSP00000301761	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary pheochromocytoma-paraganglioma Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Aug 15, 2023	This missense variant replaces threonine with alanine at codon 9 of the SDHAF2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with SDHAF2-related disorders in the literature. This variant has not been identified 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 04, 2024	This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 9 of the SDHAF2 protein (p.Thr9Ala). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SDHAF2-related conditions. ClinVar contains an entry for this variant (Variation ID: 463820). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The alanine 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. -

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	curation	Sema4, Sema4	Dec 26, 2021	- -
Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Mar 08, 2022	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. -

Paragangliomas 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Aug 11, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.053
BayesDel_addAF	Benign	-0.23	T
BayesDel_noAF	Benign	-0.56
CADD	Benign	6.4
DANN	Benign	0.77
DEOGEN2	Benign	0.0068	.;T;.;.;.;.
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.0029	N
LIST_S2	Benign	0.45	T;T;T;T;T;T
M_CAP	Benign	0.017	T
MetaRNN	Benign	0.034	T;T;T;T;T;T
MetaSVM	Benign	-0.95	T
MutationAssessor	Benign	0.14	.;N;.;.;.;.
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.30	T
PROVEAN	Benign	0.36	N;N;.;.;.;N
REVEL	Benign	0.12
Sift	Benign	0.42	T;T;.;.;.;T
Sift4G	Benign	0.35	T;T;.;T;T;T
Polyphen		0.0	.;B;.;.;.;.
Vest4		0.075, 0.048, 0.035, 0.080, 0.060
MutPred		0.094		Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);Loss of sheet (P = 0.0181);
MVP		0.17
MPC		0.17
ClinPred		0.033	T
GERP RS		1.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.2
Varity_R		0.036
gMVP		0.31

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.12		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: rs1554983610; hg19: chr11-61197643; COSMIC: COSV57100266; COSMIC: COSV57100266;