NM_004168.4:c.985C>G

Variant names:

• chr5-233566-C-G
• rs771328239
• NM_004168.4:c.985C>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PP3_Moderate

The NM_004168.4(SDHA):​c.985C>G​(p.Arg329Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000616 in 1,461,862 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R329L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: SDHA NM_004168.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.61
• Publications: 3 publications found

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 Gene-Disease associations (from GenCC):

• hereditary pheochromocytoma-paraganglioma

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• pheochromocytoma/paraganglioma syndrome 5

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Illumina, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• mitochondrial complex II deficiency, nuclear type 1

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• neurodegeneration with ataxia and late-onset optic atrophy

  Inheritance: AD Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• Leigh syndrome

  Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics, ClinGen
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• gastrointestinal stromal tumor

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Leigh syndrome with leukodystrophy

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• mitochondrial complex II deficiency

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• dilated cardiomyopathy 1GG

  Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

ENSG00000286001 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.895

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SDHA	NM_004168.4	c.985C>G	p.Arg329Gly	missense_variant	Exon 8 of 15	ENST00000264932.11	NP_004159.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SDHA	ENST00000264932.11	c.985C>G	p.Arg329Gly	missense_variant	Exon 8 of 15	1	NM_004168.4	ENSP00000264932.6
ENSG00000286001	ENST00000651543.1	n.985C>G		non_coding_transcript_exon_variant	Exon 8 of 24			ENSP00000499215.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.0000159 AC: 4 AN: 251494 AF XY: 0.0000221

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000352

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000616 AC: 9 AN: 1461862 Hom.: 0 Cov.: 32 AF XY: 0.00000825 AC XY: 6 AN XY: 727228

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000719 AC: 8 AN: 1111984

Other (OTH) AF: 0.0000166 AC: 1 AN: 60396

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.0000165 AC: 2

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Pheochromocytoma/paraganglioma syndrome 5;C5700310:Mitochondrial complex II deficiency, nuclear type 1 Uncertain:1

Dec 10, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 329 of the SDHA protein (p.Arg329Gly). This variant is present in population databases (rs771328239, gnomAD 0.004%). 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: 472422). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt SDHA protein function with a negative predictive value of 95%. 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

Oct 30, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R329G variant (also known as c.985C>G), located in coding exon 8 of the SDHA gene, results from a C to G substitution at nucleotide position 985. The arginine at codon 329 is replaced by glycine, an amino acid with dissimilar properties. This amino acid position is highly 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	Pathogenic	0.93
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	0.080
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.40	T;T;.;.
Eigen	Uncertain	0.41
Eigen_PC	Uncertain	0.30
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Pathogenic	0.99	D;D;D;D
M_CAP	Uncertain	0.085	D
MetaRNN	Pathogenic	0.89	D;D;D;D
MetaSVM	Benign	-0.72	T
MutationAssessor	Uncertain	2.0	.;M;.;.
PhyloP100		2.6
PrimateAI	Pathogenic	0.85	D
PROVEAN	Pathogenic	-6.3	.;D;D;D
REVEL	Uncertain	0.47
Sift	Pathogenic	0.0	.;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		1.0, 0.99	.;D;D;.
Vest4		0.93
MutPred		0.70		.;Loss of stability (P = 0.0672);Loss of stability (P = 0.0672);.;
MVP		0.60
MPC		1.5
ClinPred		0.96	D
GERP RS		2.3
Varity_R		0.94
gMVP		0.88
Mutation Taster		=14/86	disease causing

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

Other links and lift over

dbSNP: rs771328239; hg19: chr5-233681;