rs980397872

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM1PM2BP4

The NM_004168.4(SDHA):c.1666A>G(p.Met556Val) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000031 in 1,612,954 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 1/1 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. M556T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

SDHA
NM_004168.4 missense, splice_region

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 4.98

Variant links:

Genes affected

SDHA (HGNC:10680): (succinate dehydrogenase complex flavoprotein subunit A) This gene encodes a major catalytic subunit of succinate-ubiquinone oxidoreductase, a complex of the mitochondrial respiratory chain. The complex is composed of four nuclear-encoded subunits and is localized in the mitochondrial inner membrane. Mutations in this gene have been associated with a form of mitochondrial respiratory chain deficiency known as Leigh Syndrome. A pseudogene has been identified on chromosome 3q29. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jun 2014]

SDHA links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 15 uncertain in NM_004168.4

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.31207356).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SDHA	NM_004168.4 linkuse as main transcript	c.1666A>G	p.Met556Val	missense_variant, splice_region_variant	13/15	ENST00000264932.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SDHA	ENST00000264932.11 linkuse as main transcript	c.1666A>G	p.Met556Val	missense_variant, splice_region_variant	13/15	1	NM_004168.4	P1	P31040-1

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152128

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000405

AC:

AN:

246656

Hom.:

AF XY:

0.00000746

AC XY:

AN XY:

134100

show subpopulations

Gnomad AFR exome

AF:

0.0000682

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1460826

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

726686

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

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:

9.00e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152128

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74306

show subpopulations

Gnomad4 AFR

AF:

0.0000724

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Paragangliomas 5;C5700310:Mitochondrial complex II deficiency, nuclear type 1

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 09, 2022

This sequence change replaces methionine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 556 of the SDHA protein (p.Met556Val). This variant is present in population databases (no rsID available, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with SDHA-related conditions. ClinVar contains an entry for this variant (Variation ID: 472349). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The valine 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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 04, 2022

The p.M556V variant (also known as c.1666A>G), located in coding exon 13 of the SDHA gene, results from an A to G substitution at nucleotide position 1666. The methionine at codon 556 is replaced by valine, an amino acid with highly similar properties. This amino acid position is not 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: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.075

BayesDel_addAF

Pathogenic

0.18

BayesDel_noAF

Uncertain

0.030

Cadd

Benign

Dann

Benign

0.95

DEOGEN2

Benign

0.35

T;D;.;T

Eigen

Benign

-0.24

Eigen_PC

Benign

-0.17

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.89

D;D;D;D

M_CAP

Uncertain

0.090

MetaRNN

Benign

0.31

T;T;T;T

MetaSVM

Benign

-0.45

MutationTaster

Benign

0.85

D;D;D

PrimateAI

Uncertain

0.57

Sift4G

Benign

0.084

T;T;T;D

Polyphen

0.0020

.;B;.;.

Vest4

0.36

MutPred

0.36

.;Loss of sheet (P = 0.1158);.;.;

MVP

0.72

MPC

0.49

ClinPred

0.55

GERP RS

2.5

Varity_R

0.61

gMVP

0.44

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over