5-218368-C-G

Position:

• chr5-218368-C-G

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP6

The NM_004168.4(SDHA):​c.13C>G​(p.Arg5Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000307 in 1,304,980 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 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: 34)
  • Exomes 𝑓: 0.0000031 (0 hom.)
• Consequence: SDHA NM_004168.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: -0.166

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]

ENSG00000286001 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.059296817).
• BP6: Variant 5-218368-C-G is Benign according to our data. Variant chr5-218368-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 966890.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SDHA	NM_004168.4	c.13C>G	p.Arg5Gly	missense_variant	1/15	ENST00000264932.11	NP_004159.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SDHA	ENST00000264932.11	c.13C>G	p.Arg5Gly	missense_variant	1/15	1	NM_004168.4	ENSP00000264932.6
ENSG00000286001	ENST00000651543.1	n.13C>G		non_coding_transcript_exon_variant	1/24			ENSP00000499215.1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome AF: 0.00000307 AC: 4 AN: 1304980 Hom.: 0 Cov.: 31 AF XY: 0.00000155 AC XY: 1 AN XY: 644360

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000798

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: 0.00000191

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 34

ExAC AF: 0.0000178 AC: 2

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

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

Jan 16, 2024

This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 5 of the SDHA protein (p.Arg5Gly). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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: 966890). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae 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 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

May 23, 2024

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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.075
BayesDel_addAF	Benign	-0.17	T
BayesDel_noAF	Benign	-0.48
CADD	Benign	11
DANN	Benign	0.64
DEOGEN2	Benign	0.26	T;T;.;.
Eigen	Benign	-1.0
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.022	N
LIST_S2	Benign	0.60	T;T;T;T
M_CAP	Uncertain	0.26	D
MetaRNN	Benign	0.059	T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.55	.;N;.;N
PrimateAI	Uncertain	0.72	T
PROVEAN	Benign	-0.51	.;N;N;N
REVEL	Benign	0.078
Sift	Benign	0.26	.;T;T;T
Sift4G	Benign	0.60	T;T;T;T
Polyphen		0.0020	.;B;B;.
Vest4		0.13
MutPred		0.34		Loss of MoRF binding (P = 9e-04);Loss of MoRF binding (P = 9e-04);Loss of MoRF binding (P = 9e-04);Loss of MoRF binding (P = 9e-04);
MVP		0.38
MPC		1.3
ClinPred		0.069	T
GERP RS		0.23
Varity_R		0.079
gMVP		0.58

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: rs770866830; hg19: chr5-218483;