5-240397-A-G

Position:

• chr5-240397-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_004168.4(SDHA):​c.1472A>G​(p.Glu491Gly) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. E491A) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: SDHA NM_004168.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.69

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SDHA	NM_004168.4	c.1472A>G	p.Glu491Gly	missense_variant	11/15	ENST00000264932.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SDHA	ENST00000264932.11	c.1472A>G	p.Glu491Gly	missense_variant	11/15	1	NM_004168.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000206 AC: 3 AN: 1458418 Hom.: 0 Cov.: 29 AF XY: 0.00000138 AC XY: 1 AN XY: 725670

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 08, 2019

This variant is not present in population databases (ExAC no frequency). This sequence change replaces glutamic acid with glycine at codon 491 of the SDHA protein (p.Glu491Gly). The glutamic acid residue is moderately conserved and there is a moderate physicochemical difference between glutamic acid and glycine. This variant has not been reported in the literature in individuals with SDHA-related conditions. 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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 17, 2019

The p.E491G variant (also known as c.1472A>G), located in coding exon 11 of the SDHA gene, results from an A to G substitution at nucleotide position 1472. The glutamic acid at codon 491 is replaced by glycine, an amino acid with similar properties. 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: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Uncertain	0.092	D
BayesDel_noAF	Benign	-0.11
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Benign	0.38	T;T;.;.
Eigen	Uncertain	0.32
Eigen_PC	Uncertain	0.37
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.97	D;D;D;D
M_CAP	Benign	0.055	D
MetaRNN	Uncertain	0.47	T;T;T;T
MetaSVM	Benign	-0.44	T
MutationAssessor	Benign	2.0	.;M;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.65	T
PROVEAN	Uncertain	-3.1	.;D;D;D
REVEL	Uncertain	0.30
Sift	Benign	0.035	.;D;D;D
Sift4G	Benign	0.13	T;T;T;T
Polyphen		0.0010, 0.12	.;B;B;.
Vest4		0.59
MutPred		0.30		.;Loss of solvent accessibility (P = 0.0387);Loss of solvent accessibility (P = 0.0387);.;
MVP		0.83
MPC		0.57
ClinPred		0.93	D
GERP RS		5.0
Varity_R		0.24
gMVP		0.68

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

Other links and lift over

dbSNP: rs754324916; hg19: chr5-240512;